I paid around 13k for geothermal. Which included digging, grass seed, 4 ton unit, heat strips, desuperheater ( preheats water going to water heater from compressor heat when running). The price included removal of fuel oil. Advantage unit is indoors, I live near farms, dust clogs the outdoor units easily, making them inefficient without cleaning regularly. I could have had propane for about the same price, electricity is cheaper in my case. I don't need to worry about refueling or running out.
@alanknudson8774 I got it the summer the world wide flu broke out. Mine is bard brand. I had no intention of going for geothermal, but someone knew someone & I thought why not. Turned out propane & tank & the unit would have cost the same or more depending on what I got. Of course I had to wait until tax time to get my money back with tax credit. But otherwise I feel I got a good deal. It uses a lot of underground yard space. 4 ton requires 4 ground loop trenches 5 feet deep. Roughly 2500ft of pipe loops. Its efficient until it gets around 20 degrees or so. Then mine runs longer. They have systms that can be more efficient than mine, mine is not a variable system. One complaint people have is it doesn't put out warm heat. Fuel oil, gas, propane is significantly warmer air at the registers, it also takes longer to get to desired heating temperature. Cooling factor is amazing compared to the few standard AC units I've used. It seems to be better than the outdoor unit that is in the heat & sun, I can cool my house regardless of how hot it is, doesn't run long to do it either. Aside from pipe being underground they don't recommend any fixed or heavy objects above the loops. There are other choices for the loops. You can have wells dug many feet down, toss the loops into water that is deep enough to not freeze. They can add something to it like antifreeze, which is in mine. Not sure what the additive is called. My installer said the loops can last over a 100 years. The units themselves can last around 20 years vs 15 or less with standard. There is no air duct holes in house to outside like normal units, although there is 2 holes in basement wall for underground loops.
@@alanknudson8774 winter raises my bill about double January through march. My house is all electric. I got a hybrid heatpunp water heater too, dehumidifies basement as bonus. Summer electric bills were around $50 or $100. Highest winter was $280. I expect higher as energy rates continue to increase. Although I went solar for just a little more than I paid for geothermal. I'll probably get a couple of electric bills because of some upgrades I did, battery backup for essentials, unfortunately geothermal initial draw exceeds the standard breaker panels most old homes have, it uses just a little more than 100 amps for startup. You can buy soft start kit to eliminate light flickering at startup as most see in their home when a large appliance kicks on. It would also be able to loaer amps tonbe usable on my battery backup.
@@Gamerz00760 That's a great deal on a pretty great system. Geothermal system do often run a little lower output temperature, though dandelion energy's new unit has higher temperature air. The lower temp lets you run higher effeciency, but increases the ductwork you need, for the same heat delivery I'm a big fan of radiant for lower loop temperatures, as it doesn't have the same draw back of ducted systems, where blown air has a natural cooling effect under about 110 degrees Fahrenheit. The air feels cold but is warm still. Radiant just feels warm all the time without the air flow issue necessarily thanks for coming back and sharing the install details, thats great information to have!
@@BatteryBuilds-p5x I haven't looked into radiant heating much, I think my only concern is durability. If there is heavy furniture, or party with kids or adults does the floor shift enough to damage the loops or cause leaks.
Financially sense depend on the price and the timeframe ! I live in Denmark and i make some of the installation myself and i expect a pay back time of about 4 - 5 years and much more comfort
Great point! One advantage of geothermal, or solar even Is that there’s a DIY option that’s much much cheaper. They’re is not a similar power line DIY option or natural gas DIY option The closest being perhaps firewood
Ground loops are situational and depend on how cold it gets and how long it stays that cold. It is entirely possible to pull all the available heat out of the ground around the loop during a really cold winter. I've seen it happen. On the other hand a water source system can give reliable heat even during the coldest years. Pull the water out of the well, pull the heat out of the water, dump the cold water into any near by stream, pond, etc. While air source systems have improved they still have issues when it gets really cold.
This is a great option for a very small number of customers, less than 1 out of 1000 or so it's benefits are large in cold climates with high ground water, or flowing water nearby, but not great for milder climates with deeper water tables. Deeper water tables tend to have much harder water, and fouling becomes a problem, as well as water usage in my area (desert climate.) we're thinking of how to do a 100 home subdivision on a customers development where they hit water at 1000' down, but it came up 68degrees farenheit. Tons of good reasons to do it, but lots of reasons not to as well. i'm hoping i can make it work and post a video about it later down the road!
I have had my Waterfurnace for 20 years it was $5k more than propane at the time of installation. It paid for itself in the 3rd year in the 10th year I installed solar and never looked back. Well water which is geothermal in nature is plentiful and cheap and never runs out if returned to it's source.
@@deathgun3110 No drought here we have more water than we have ever had and besides you don't use up water you put it back 3 degrees colder so it can warm up to be reused.
I agree open loop systems can be incredible in terms of cost to install and run when done right, in my area its not a straight forward system We have deep water tables 400-900' deep generally, and water use restrictions that makes it difficult. Because of that, closed loop are usually the cheapest in my general vicinity A few open loop systems we are looking at though, i'll share the projects if we end up building them!
If you have the land and access to a backhoe, air source geothermal is an Idea. Simple black pipe stretched for couple hundred feet, and an extra fan. Maybe a few lines of it. Instead of liquid in the ground, air is drawn through the ground and blown over the coils of air source heatpump. Ground temp here in Ga is about 65° . Head up to Michigan and you are around 50°. A box around outdoor unit to direct ground conditioned air over coils and you accomplish same thing. $2-$4k additional cost.
I like where you’re minds at, I have something you’ll want to subscribe to see I’ve been using something on a customers house the last 2 years that looks similar. Great thread
@alanknudson8774 I saw it from a 80 year old retired engineer. Lived in Nebraska. Had a greenhouse with no backup heat. Just air coming through pipes in the ground. 15-20 years. The greenhouse was full of citrus trees. Local grown oranges in Nebraska. Again, zero backup heat in greenhouse. House was set up with air on heatpump.
@@pathfollower Only concerns would be radon, but if you're just using it on a heat exchanger or on a heat pump coil to keep a steady temp, would work well. If you can custom build a heat pump, knowing you have a set temp for the outside air can allow you to use some tricks to increase the efficiency of the whole system by a lot.
Maybe also consider a system that draws on the above ground air when temps are in the range that your heat pump can reasonably use (depends on heat pump efficiency), then when the air is too cold to efficiently get is heat from above ground, switch to below ground air. The reason is that the ground will eventually cool down and become less effective as a heat source and by using the above/below ground source(s) one can minimize what is needed to gather below ground heat and/or keep the best source (the ground) for when it is needed the most, usually the dead of winter. Just a thought.
Solving heating and cooling needs for 45-50 weeks of the year is relatively easy. Designing a system that meets those needs, infallibly, for 52 weeks out of every year, for many years, is a completely different challenge. Also, solving heating needs in zone three is about as hard as solving cooling needs in zone six. How could the same geothermal (or any) system possibly meet both of those heating and cooling needs, when they are so disparate? You mention that air-source heat pumps, as part of a good mini-split system, have become more capable during very cold temperatures, and you're not wrong. However, the way they achieve this is through a dramatic increase in the amount of energy used to defrost the coils, repeatedly. I was really hoping you'd show the power utilization graphs from a zone six or seven system, because an air-source heat pump in those locations uses a LOT more power, when it gets down to normal winter temps in those zones. I like the idea of one or more air-source mini-splits, paired with a very well-built masonry heater; the best implementation of the newest technology and the oldest technology. With a right-sized solar/battery array, this solution works very well for zone 6 or colder. It would make no sense at all in zone 3 or warmer.
ruclips.net/video/iQ_HR4hAqhQ/видео.html In this video I go over the problems you have to solve for a well designed solar and battery without wasting money I go over 3 problems 1. The night time problem 2. The winter time problems 3. The snowstorm problem But I didn’t really talk about the snowstorm problem very much. Basically the snowstorm problem is what you’re referring to, how to you get through the 2-3 weeks a year when solar and battery becomes exponentially more expensive as a backup power source. There are many solutions to the snowstorm problem, we’ve defaulted to 1 which is a automatic standby generator, because it can get us both through a snow storm, or any spike in electricity we weren’t expecting, and it can double as backup in the case of an inverter or Bms failure I tried to make the point in this video that geothermal is cost effective past climate 4-5 and for Offgrid it’s cost effective even in climate 3 in some cases
@@alanknudson8774 - If you're not familiar with a masonry heater, they are remarkable structures typically built as the core of a home. They are massive, meaning they have a great deal of thermal mass. They burn a relatively small amount of fuel (wood) very quickly and at very high termperatures. Those temperatures flow through a series of masonry tunnels or chambers, heating the thermal mass and discharging far less of the heat created out of the flue pipe than a conventional wood stove. They have no moving parts, typically only need to be fired 1 or 2 times per day, (no tending) and are an essentially infallible way of heating any home that was designed around one. If you have dry wood, you will be warm. You mentioned in this video that you can't always rely on propane or natural gas deliveries. The same is true of the gas or propane for a generator, which has a lot of moving parts that may fail during a "snowstorm". I would also mention that in certain parts of the country, there is insufficient solar potential for much longer than 2-3 weeks. It's more like 7-8 weeks, in some places. Ask me how I know. :)
You can do geothermal DIY... if you're inclined towards that sort of thing. $5700 for the equipment to do a 4-5 ton geothermal system from MrCool. If you're building a new house, just do the loops when you're doing the foundation work. A lot of people are not very inclined for it, but HVAC is actually far simpler than people think and the new systems are so good for it. Speaking of gas... there are on property sources of fuel gas when you're off-grid with a septic tank.
Excuse my ignorance, but why is cooling being ignored on the graph, especially in Arizona? Doesn't it use the same system to get similar benefits from geothermal in summer?
Cooling is an odd duck for geothermal. And a lame duck for offgrid So i ignored it for the most part. Essentially, mini splits outperform geothermal aggressively in cooling mode for most climates like Arizona, so there isn't a benefit to cooling with geothermal versus cooling with a mini split generally. (not always the case, but generally) Geothermal systems, tend to lose efficiency over time if you get the loops too hot, it pushes the moisture away from the loop because of the heat which lowers efficiency which causes the loop to heat up etc etc. For an offgrid home, you have plenty of excess electricity in the summer generally, because of the Day to night problem and the winter time problem, covered in my earlier video "how not to waste thousands of dollars when designing your offgrid home" So effeciency gains in summer are minimal, and the value of those gains is nearly 0 for an offgrid home running on geothermal. All of the gains tend to be in heating in the winter instead, or producing domestic hot water in the winter etc hope that helps, i'll try and explicitly show those calculations in our next video on geothermal systems
That's a deep point and telling, about the lack of expertise in the hvac industry. Best route for a homeowner is usually to get an engineer with some experience with similar systems, and pay them to sign off on the design, talk to the inspectors, and check the installation via startup and diagnosis. I agree that done well, geo is an excellent choice where heat or cool needs are at 5 btu tonnes or more.
Yes that is biggest problem in residential building, designing before building is so rarely done, commercial build has to have everything in BIM and every screw, nail accounted for. residential build you can even see moving walls mid build lol. I like "shallow" geo in areas with high water table, that way construction is a lot cheaper with same performance.
The problem is trying to do it on a house by house basis. The underground infrastructure needs to be done at larger scale. Individual houses should just connect to that shared infrastructure. At that scale, it's cheap.
I suspect I live far enough North (Climate zone 7A) that air-source heatpumps would have a huge drop-off in efficiency during the coldest week of the year. Maybe directional drilling can help cut costs: I do live in oil country. My understanding is that the biggest expense for a ground source heat-pump is actually burying the piping.
burying the pipe is a big one, the distribution system (ductwork) can also be a bit more costly, as many geothermal systems run lower temps, and higher CFM so bigger ductwork. Also the geothermal heat pump tends to cost 50% more than a normal air source heat pump if not more so a few items besides drilling to consider when doing geothermal. a bit more labor too, depending on the setup, for the pump station and if you set up a desuperheater especially
@@BatteryBuilds-p5x I may have found a loop-hole for the ductwork: many systems are over-sized, especially if you upgrade the insulation during the upgrade.
Great content. Counter point for you to consider is air source heat pumps keep getting cheaper and more efficient. A 1 ton mini split can be purchased for well under $1000 these days and the price keeps dropping. Also, with the switch from r410 to r32 they have picked up some efficiency. Additionally, pv and battery storage keep dropping in price. I wonder if 5 years from now geothermal will still be competitive compared to air source, for off grid living
Mini splits are interesting… very cost effective often. Most are made overseas, and with the new tariffs will likely go up a fair bit in pricing. The cheap ones generally can’t handle cold climates with high efficiency. So I’d say you get a lot for paying for a nicer one. Compared to geothermal they lose out as the house and the loads get larger. But for small houses, low loads they’re ideal and super effecient! I think geothermal going to gain ground mini splits in a lot of markets. Basically mini splits destroyed geothermal sales and geothermal is adopting mini split technology going forward should be quite interesting. Mini splits struggle to get good air distribution, for higher end homes that’s an issue as well. Curious to see how it evolves going forward myself
The ground gets warmer the deeper you dig so I have always assumed that running costs for GSHP would be cheaper if you could just dig a deep well to the water table and draw water up and through a heat exchanger and then back into the ground some distance away. I don't see this suggested so is this a regulation/code issue or what ?
Its not against regulation where i live, it is simply not cost effective generally. Unless you needed the well because your house was offgrid to begin with! Water wells are often 4-10x more expensive per foot than geothermal wells, because you drill it bigger 6 inch generally, then you case it with steel or pvc which is expensive per foot, then you backfill and grout the hole outside the casing, then you put a well pump on a drop pipe down the hole to pump it. So there are many situations where open loop works, but the easiest one is, you already need the water well, and its relatively close to your house Then it can be magical it does sort of ignore what i think is one of the most under explored benefits of geothermal for offgrid houses, closed loop systems aren't power sources, there really really large batteries so you can store heat or power in them in a way that simply isn't possible with lithium batteries
We have an old air heat pump system as we live in zone 3. Works ok when the temps are moderate, but not so well when it gets well below freezing. Something I have contemplated to help boost it some, at low cost is the following: Bury a few large copper pipes deep in the ground (in my area, 9 to 10 feet or so). Into those pipes will go highly conductive powders, and some non copper reactive liquid. Then copper tubing, which will be converted into "heat pipe" type tubing will be wrapped around these copper pipes, especially at the base. As the tubing and pipes get closer to the surface, they will be highly insulated. Anyways, I would probably flatten out this tubing and try to make it have physical contact with parts of the outside condenser unit. I can't do this, because we have too much shade on our property, but Solar Air heaters are really criminally under used. They are relatively easy to make and install, and can be made quite inexpensively. If you do it right, it can really cut down on the amount of daytime energy you need to use, whether that is electricity, propane, natural gas, wood stove, etc. Currently we are experiencing a somewhat unusual cold snap with lows into the mid teens and a bit lower. To help my heat pump out, I've put a 15" smokeless fire pit/stove nearish the condenser, put a burn barrel over the top of it (upside down, the bottom has some vent holes on the top and on the sides), and then I wrapped an IR reflective foam loosely around it all (with plenty of space to allow the fan to get enough air and to not over heat the condenser). Some of the wood is just waste wood from my yard that I can't use in my wood stove because it would create too much creosote, it's too small, or the like. Yes, it is somewhat near the house and may not be fully legal, but I consider this set up much, much safer than an inside woodstove with the potential for chimney fires. Sparks cannot escape this system, and there is no chimney. No, it is not very efficient, but if you're mostly using yard debris, that's not really an issue.
Solar to air heaters have their place, there in my list of technologies we need to analyze as alternatives to what we typically would use. Heat pipes are too. heating the air near your compressor with waste wood is a decent way to go, the hard part being that much of the air is going to escape. But it is clever as a way to boost output only when it's cold outside. I have a fascination with modifying heat pumps to make them multi-source. Like increasing the heat intake on the compressor. One way you could perhaps improve your setup would be to bury the fire source, so that you're looping in the ground around it. So more of the heat your generate is "stored" in a cold snap, the worst load condition is generally right before the sun hits your windows. So maybe by having the stove buried, with air pipes through the ground around it going to the compressor, or even rerouting the compressor refrigerant line to go through the hot dirt battery before hitting the outdoor unit, would allow it to use that heat through the night. Ideally you'd end up with 13-14 hours of extended efficiency in the night time hours, in theory at least. Would be a interesting use case, thanks for posting your ideas, they're really interesting for me to think about!
@@BatteryBuilds-p5x The combo of the aluminized/IR reflecting surface of the foam surrounding the condenser unit and reflecting the IR to it, and the fan on the condenser unit that sucks air in and up, does help more heat to get to it, but yeah, it is not ideal, because a lot of heat is being lost at the top. Another IR reflector above the fire pit/stove and burn barrel combo, and angled down towards the condenser unit would help a bit. I'll have to think about your suggestions a bit. Thank you for the reasoned and thoughtful reply, for now. Cheers
I think geothermal only makes sense if you are in extreme temperatures where an air source would have challenges or be incapable... like below -22F (that is about the limits of the modern air source heat pumps). I think there is room for "geothermally" supporting air source heat pumps, though. For instance, if you had a hole, you could actually have a cooling radiator in the hole and fill it with an inert oil, like mineral oil. Enclose the hole with something sealed and ensure it has fantastic ground contact. Yes, it could get saturated, but it will dissipate with time. Another good option is using VRF Heat Pump setups. We don't really have fully integrated setups today, but I would love to see these where we incorporate out water heaters (these do exist), our refrigerators and freezers, and more. We have these various heating and cooling demands all around our homes and we can move hot to cold in any of them.
Inverter technology has made closed loop geo largely obsolete. But once the pipes are in the ground you can not compete with an INVERTER driven geo system. The problem is water to air or water to water has 1 inverter driven system on the market .
It’s a great point. Inexpensive Inverter systems, drove both the very high efficiency and the very wide range of outputs for mini splits. It gets rid of fans and recirculation pumps This is the 1 reason geothermal has been lagging generally the last 6 years approximately. When you bring inverter driven components to GEO the math comes back hard for geo except when loads are quite small. Variable speed geothermal can accomplish 6-8 COP ranges in some cases for Offgrid in the winter heat pumps. So only as loads get smaller and smaller does geothermal become less and less effecient compared to Air source variable speed systems
Inverter-based ground-source water-water heat pumps are extremely common here in Scandinavia, there's tons of them. I'm surprised it's not the same in the cold parts of North America. Air-source heat pumps are great if it doesn't get colder than 10F or so but once it starts getting colder than that, their efficiencies really drop. Having access to the geothermal heat reservoir and letting a ground-source pump work at a COP of 5-6 throughout the cold part of the year will, long-term, pay off the installation costs.
@patrikj government funding for geothermal fields caused a boom about 15 years ago. Since then the few companies specializing in geothermal water source equipment just didn't invest in manufacturing upgrades . And now with time of day energy harvesting / storage you can run an air source during a 20 F day and use the stored 160F water for heating at night. So new fields are pretty much a dead concept. From an offering to the potential homeowner anyway.
Geothermal is an excellent method of heating and cooling if implemented correctly. The problem that I see is that we want it cheap and easy. I've reviewed a lot of systems and have found their implementations to be questionable at best. Take a look at what they have done in northern Europe and then decide. But be prepared to spend because you are looking at 10+ year pay backs.
Air source will never compete with ground source (geothermal). Geothermal is always more efficient all year round for both heating and cooling. Whether its 80, 90, or 100 outside, its still 65 in the ground (Georgia). Whether its 40, 30, or 20 outside in the winter, its still 65 in the ground. The only time an air source HP is as efficient as a geothermal system is when the temps are mild and you need neither heating or cooling. That's the beauty of geothermal, the ground temps are in a range (in north America) where the heat pump is most efficient for either cooling or heating. For air source, you need cooling most when it's hot, but that's when air source is least efficient. Or in the winter, when it's the coldest ouside, that's when you need the most heat, but that's also when an air source HP is least efficient. As for efficiency, air source mini splits or ducted inverter heat pumps never get above 16 EER (btus per watt) when it's 95 outside. Most at 95 deg and full load don't get above 13 EER, only small 6k btu mini splits get to 16 EER. A geothermal system can get over 22 EER with loop temps at 60-70 degrees. With the 30% tax credits geothermal doesn't cost any more than an air source system, so unless you don't have the space for a horizontal loop and can't drill a vertical loop, geothermal is always better.
Your heating system still won't work without electricity. You need a electric blower to move air through a furnace or an electric pump to move water through a radiant system. Only heater that uses no electricity is a wood stove. Gas won't save you in a power outage.
How much land do you need to chill to heat a home? I see the possibility for a road of houses being able to freeze their whole plots inc mains water and drains
great question. Most houses have 100' 150' trenches per ton of hvac load. However, they only use a fraction of the soil temperature. Meaning most of the heat being pulled out of the ground is within 3' of the trench, past 3' a temperature of 5 - 10 degrees warmer or colder than the surrounding soil is typical Although in northern climates, where you heat a lot and cool a little that cold pocket gets bigger and bigger each year. Which is a problem in sweden particularly. It makes for a great thermal storage system but has issues when you're using soil a source rather than long term heat storage, (meaning you replace the heat you take out on average)
Using propane or any other fuel that someone else provides from off site, is not "off grid". All of the extraction, refining, production, and distribution of those fuels are very much "on grid".
Offgrid as I’m using it in the video would be something like, how long can you last without outside intervention. So propane would be fine as an input, but how long can you really go until you need refilled? Offgrid as your defining it, would be can I survive or live independently for all time without outside help. Would be pretty awesome, much much more difficult to achieve and likely not what our customers actually want.
@@BatteryBuilds-p5x Understand. There's ideal, then there's practical. I'll be the first to admit that I've had dreams of having an entire propane tank trailer, full, on my property. Not for the primary energy source, but to fall back on. Should last an entire lifetime that way lol!
Geothermal makes sense for cooling in northern areas, but directly, not through running them a heat pump. Air source equipment is so much cheaper for a small off grid house, that geothermal heat pumps don't make sense. But what I'm going to do is that every time I have to dig a trench for some reason, I'm going to run a ground loop in the bottom of it. In the cold spells in winter in the winter, I'll use that to pre-heat air passing past the air source mini split. The rest of the time, I'll use it keep my water from from freezing, and minimizing the night time dip of my eventual greenhouse. Use a wood stove when I'm awake, and a propane hot water feeding a radiant floor when I'm not. My guess is that I'll find out that it is better to cut firewood, then to pay for more propane to run the generator or put in more panels. It is just too cloudy in Northern Idaho!
Geothermal in northern Idaho could be ideal. Especially if you have a septic system. It’s not always a good idea, but running geothermal lines underneath a septic leachfield or alongside a water well line feeding the house are often very good ideas to save money. Open trenches like your saying are also a great idea many times. The greenhouse heat load can pair well with the house system. I’d say if you’re already looping and pumping, you may as well use the heat pump as well!
Geothermal is complicatet, in my country (Denmark) geothermal is actually earth heated by the sun in the sommer time so not heat generate by earth. And we always do it in "lines" 3 feet in the ground with 1 to 2 feet in-between.
never ran out of gas. regularly lose power during storms multiple times a year. reliability is NOT buying a heat pump because they depend on electricity.
Certainly depends on the local weakness you’re optimizing for. Electricity is usually less reliable, in Offgrid ours has gotten to be pretty good. Especially with reliable backup generators for storms etc. When I say reliable, I’m meaning if you had grid wide, society wide shortages or failures. Not a great measure of likely use, just a piece of mind feature many people want when it’s available and they can afford it
Your illustration at 1:37 is correct for a cooling cycle, but your explanation is backward. When in cooling, the metering device creates a pressure drop causing the refrigerant to "boil off" and absorb heat (like a kettle on a stove boils). Compressors compress low temp-low pressure gas to high pressure-high temp gas. Heat rejection outdoors causes the refrigerant to condense back to a liquid and repeat. A heat pump adds a "reversing valve which swaps the coil function of heat rejection to indoors and heat collecting outdoors. Yes, i do this for a living. This is a basic explanation of a refrigerant cycle. Addind water loops indoors, outdoors or both complicates the cycle a bit. But its still basicly the same principle. Your just changing where your heat comes from and goes to.
Vertical is more expensive generally. We pay $21/ft of borehole plus a mobilization fee of $3500 We typically need between 100ft to 200ft of borehole per ton. So for a 3 ton system you’re talking $6300-$12,600 plus the mobilization fee. Backhoe is normally $9000-$10,000 and can be self preformed often
Vertical is typically used when there’s land constraints and horizontal when there isn’t, or during new construction. It can be as cheap as $7,000-$8,000 in the right circumstances (backhoe on site, or installed during over-ex and backfill, to save equipment and people trip to the site)
We lets go over the pluses. Approximately 70 percent of energy is low energy heating cooling, for the cost of a fan, pump , radiator you can keep the house at the temperature of the earth 20 ft down. Well above freezing well below comfort. Now add a heatpump you get comfort at very efficient rates. Cons , burning methane to power generators and send that energy down the line costs 8 to 40 cents per kw to run an air heatpump at that is cheaper. I smell government interference and price fixing probably benifiing companies and voters with cheap electric power
@johnschneider931 I have created bids on several commercial geothermal ground source heat pump systems in my career. Most of the cost differential between air source and ground source comes from digging the holes and installing the pipe. If there were a cheaper way to dig holes and bury the pipe, then ground source heat pumps would become king everywhere there is enough land to put the wells.
@@peterirvin7121 another big concern is realtive effeciency Geothermal has been losing ground in relative efficiency compared to Air source units in recent years mainly form cheap variable speed ASHP. But geothermal is gaining ground by switching to variable speed, and by innovations in the drilling side that are starting to change the game back in its favor. PS. rate hikes make it better for geothermal too, so see that coming in the future as well
Also have a look at hydronic underfloor heating, that is a game changer if you want to go of grid. With the water loops in a thick screed layer, it will store the heat energy and slowly release it into the building. Depends on the insulation and outdoor temperatures a room temperature drop of below 1°C over night without starting the heat pump is possible. You charge to floor in the day while the sun is shining
I’m a big fan of hydronic. And concrete screeds in general.We’re trying to permit a house that heats and cools with radiant next month, will definetly have videos to show how it goes
Most geothermal is just a ripoff. Local companies wanted $10-14k to replace our old unit. Replaced it myself. Unit, tools, fittings, everything $2700 with beer money left over.
I love hydronic, especially for Offgrid! We’re working on a house plan now that uses hydronic for heating and cooling. I have a video on Corbett lundsford’s home performance channel that is a clip from a consultation he did for me on how to manage erv and air flow on a hydonically heated and cooled house
@@BatteryBuilds-p5x seven by 100 watts? so 700watts total, during a sunny day, some days cloudy. And in case of a serious storm the solar panels removable to shelter, or protection put on top to prevent damage. Ideally, in the future a machine should roll out the solar panel protection like a DVD/CD cassette disk can go in and out of the computer.
How can you suggest that a heat pump or ANY electrically driven device is better for off grid? When solar panels are your only source of electricity, anything you burn is a much better source of heat. Propane being the most available with little intervention to maintain heat with little or no electricity or human input (loading wood in a stone) which would be cost prohibative if done by PV panels inverters and Batteries
For a cabin, or a small seasonal use house that is the case. Solar is required, but something like an ecoflow delta 4 is big enough. However once you’re talking about full time use, you need the inverter, the solar and the battery. For cooling, lights etc. So the question becomes, what’s cheaper? Propane across time or solar and battery across time. A hybrid approach is often the cheapest, propane and solar together However, if you wanted a “doomsday” Offgrid house, where propane deliveries would have stopped Or if you want to build in an area where propane delivery isn’t a viable option Or if you’re load and runtime in propane was large enough ($1,000-$2,000/yeat) Then geothermal plus solar and battery start to have a payback compared to propane, plus a propane tank for heating
In ideal scenarios you'd want dual source and one that doesn't have to have fuel supplied. Since a geothermal heat pump usually has a COP of about 5 it means the amount of heat you get will be about 5 times a resistance heater. Then on too of that you'd orobably want a wood stove since in a situation where you were cut off from external inputs it's difficult to refine your own propane but easy to find wood around. The next question is if you could run a propane generator to run the geothermal heat pump would you actually get more units of heat out of the same amount of propane? So lets say you wanted to figure this out. If you have 8000 cubic feet (1000 square feet * 8ft ) and you want to heat from 20F to 72F you need something crazy like 55000 BTU. An electric resistance heater will put out about 3.4BTU per watt meaning you'd need near 16kw of heaters. A geotgermal with a COP of 5 will do 5 times that amount so you need 3.3kw to output that much heat. A 90% efficient propane heater will use about 0.67 gallons an hour to output that amount of heat. A 4kw propane generator at 100% load runs at about 0.67 gallons per hour. So in this case I would probably prefer the geothermal, battery backup with solar, and small generator which can run if the solar battery backup drips below 20% capacity to top it up a bit and keep the system running. If you were running ab air source heat pump that had a COP of 3 at that temperature swing it would make more sense for the backup heat to be a propane heater directly as the heat pump would need much more fuel to keep the place heated but the trade off being you now don't have the generator which can be used for things other than heat when heat isn't needed.
@@Snerdles There is also a big factor, I haven't covered yet on my channel. Which is the fact that you need almost in every case, a back up generator. So you're not paying for a generator or not, you're only paying for the incremental fuel cost of the generator. I didn't explicitly state this in the video, but it's the reason we generally design for 24 hours or around there of battery usage assuming no solar. Because we're relying on a generator for the days outside of that window, or even abnormal changes in energy usage like a long thanksgiving party, or a broken compressor running more than it normally would. one of the very common "high use" scenarios is actually a customer leaving something on, like a space heater which is our worst enemy in an Offgrid house, or not changing hvac filters and their units start short cycling as a byproduct So variable power generation from gas or propane is very valuable and expensive to replace without big batteries and home load control and monitoring to identify failures and alert the customer or shed that load before the customer has to respond to it, or risk losing power
@@Snerdlesyou forget that with an efficient setup the waste heat from tge generator is also used, making ut always more efficient to run a heatpump because you still get the heat from tge propane directly, you can just multiply a portion of it
.........and of course...the HEAT will Kill you First!..........although 1.5 degrees (C) average temperature increase was predicted by the year 2100...well that happened this year !!!! ......its accelerating !!!
Where I am from we have 130*F temp swing between seasons and a 6FT deep frost line. Air source is less than useless in my climate. For heat pumps Deep geothermal is only electric option.
I paid around 13k for geothermal. Which included digging, grass seed, 4 ton unit, heat strips, desuperheater ( preheats water going to water heater from compressor heat when running).
The price included removal of fuel oil.
Advantage unit is indoors, I live near farms, dust clogs the outdoor units easily, making them inefficient without cleaning regularly.
I could have had propane for about the same price, electricity is cheaper in my case. I don't need to worry about refueling or running out.
That’s pretty fantastic
What type of system did you get?
Was this a recent install by chance?
Would love any thoughts you’d like to share on it!
@alanknudson8774
I got it the summer the world wide flu broke out. Mine is bard brand. I had no intention of going for geothermal, but someone knew someone & I thought why not. Turned out propane & tank & the unit would have cost the same or more depending on what I got. Of course I had to wait until tax time to get my money back with tax credit. But otherwise I feel I got a good deal.
It uses a lot of underground yard space. 4 ton requires 4 ground loop trenches 5 feet deep. Roughly 2500ft of pipe loops.
Its efficient until it gets around 20 degrees or so. Then mine runs longer. They have systms that can be more efficient than mine, mine is not a variable system.
One complaint people have is it doesn't put out warm heat.
Fuel oil, gas, propane is significantly warmer air at the registers, it also takes longer to get to desired heating temperature.
Cooling factor is amazing compared to the few standard AC units I've used. It seems to be better than the outdoor unit that is in the heat & sun, I can cool my house regardless of how hot it is, doesn't run long to do it either.
Aside from pipe being underground they don't recommend any fixed or heavy objects above the loops.
There are other choices for the loops.
You can have wells dug many feet down, toss the loops into water that is deep enough to not freeze. They can add something to it like antifreeze, which is in mine. Not sure what the additive is called.
My installer said the loops can last over a 100 years. The units themselves can last around 20 years vs 15 or less with standard.
There is no air duct holes in house to outside like normal units, although there is 2 holes in basement wall for underground loops.
@@alanknudson8774
winter raises my bill about double January through march.
My house is all electric. I got a hybrid heatpunp water heater too, dehumidifies basement as bonus. Summer electric bills were around $50 or $100. Highest winter was $280. I expect higher as energy rates continue to increase.
Although I went solar for just a little more than I paid for geothermal.
I'll probably get a couple of electric bills because of some upgrades I did, battery backup for essentials, unfortunately geothermal initial draw exceeds the standard breaker panels most old homes have, it uses just a little more than 100 amps for startup.
You can buy soft start kit to eliminate light flickering at startup as most see in their home when a large appliance kicks on. It would also be able to loaer amps tonbe usable on my battery backup.
@@Gamerz00760 That's a great deal on a pretty great system. Geothermal system do often run a little lower output temperature, though dandelion energy's new unit has higher temperature air. The lower temp lets you run higher effeciency, but increases the ductwork you need, for the same heat delivery
I'm a big fan of radiant for lower loop temperatures, as it doesn't have the same draw back of ducted systems, where blown air has a natural cooling effect under about 110 degrees Fahrenheit. The air feels cold but is warm still.
Radiant just feels warm all the time without the air flow issue necessarily
thanks for coming back and sharing the install details, thats great information to have!
@@BatteryBuilds-p5x
I haven't looked into radiant heating much, I think my only concern is durability. If there is heavy furniture, or party with kids or adults does the floor shift enough to damage the loops or cause leaks.
Financially sense depend on the price and the timeframe ! I live in Denmark and i make some of the installation myself and i expect a pay back time of about 4 - 5 years and
much more comfort
Great point!
One advantage of geothermal, or solar even
Is that there’s a DIY option that’s much much cheaper. They’re is not a similar power line DIY option or natural gas DIY option
The closest being perhaps firewood
Ground loops are situational and depend on how cold it gets and how long it stays that cold. It is entirely possible to pull all the available heat out of the ground around the loop during a really cold winter. I've seen it happen. On the other hand a water source system can give reliable heat even during the coldest years. Pull the water out of the well, pull the heat out of the water, dump the cold water into any near by stream, pond, etc. While air source systems have improved they still have issues when it gets really cold.
This is a great option for a very small number of customers, less than 1 out of 1000 or so
it's benefits are large in cold climates with high ground water, or flowing water nearby, but not great for milder climates with deeper water tables.
Deeper water tables tend to have much harder water, and fouling becomes a problem, as well as water usage in my area (desert climate.)
we're thinking of how to do a 100 home subdivision on a customers development where they hit water at 1000' down, but it came up 68degrees farenheit. Tons of good reasons to do it, but lots of reasons not to as well. i'm hoping i can make it work and post a video about it later down the road!
I have had my Waterfurnace for 20 years it was $5k more than propane at the time of installation. It paid for itself in the 3rd year in the 10th year I installed solar and never looked back. Well water which is geothermal in nature is plentiful and cheap and never runs out if returned to it's source.
I'll hope that your groundwater level isn't decreasing after all of these droughts.
@@deathgun3110 No drought here we have more water than we have ever had and besides you don't use up water you put it back 3 degrees colder so it can warm up to be reused.
I agree open loop systems can be incredible in terms of cost to install and run when done right, in my area its not a straight forward system
We have deep water tables 400-900' deep generally, and water use restrictions that makes it difficult. Because of that, closed loop are usually the cheapest in my general vicinity
A few open loop systems we are looking at though, i'll share the projects if we end up building them!
If you have the land and access to a backhoe, air source geothermal is an Idea. Simple black pipe stretched for couple hundred feet, and an extra fan. Maybe a few lines of it. Instead of liquid in the ground, air is drawn through the ground and blown over the coils of air source heatpump. Ground temp here in Ga is about 65° . Head up to Michigan and you are around 50°. A box around outdoor unit to direct ground conditioned air over coils and you accomplish same thing. $2-$4k additional cost.
I like where you’re minds at, I have something you’ll want to subscribe to see
I’ve been using something on a customers house the last 2 years that looks similar.
Great thread
@alanknudson8774 I saw it from a 80 year old retired engineer. Lived in Nebraska. Had a greenhouse with no backup heat. Just air coming through pipes in the ground.
15-20 years. The greenhouse was full of citrus trees. Local grown oranges in Nebraska. Again, zero backup heat in greenhouse. House was set up with air on heatpump.
@@pathfollower Only concerns would be radon, but if you're just using it on a heat exchanger or on a heat pump coil to keep a steady temp, would work well.
If you can custom build a heat pump, knowing you have a set temp for the outside air can allow you to use some tricks to increase the efficiency of the whole system by a lot.
@RussellWaldrop Didn't know that about steady state temp efficiency. That's very interesting.
Maybe also consider a system that draws on the above ground air when temps are in the range that your heat pump can reasonably use (depends on heat pump efficiency), then when the air is too cold to efficiently get is heat from above ground, switch to below ground air. The reason is that the ground will eventually cool down and become less effective as a heat source and by using the above/below ground source(s) one can minimize what is needed to gather below ground heat and/or keep the best source (the ground) for when it is needed the most, usually the dead of winter. Just a thought.
Solving heating and cooling needs for 45-50 weeks of the year is relatively easy. Designing a system that meets those needs, infallibly, for 52 weeks out of every year, for many years, is a completely different challenge. Also, solving heating needs in zone three is about as hard as solving cooling needs in zone six. How could the same geothermal (or any) system possibly meet both of those heating and cooling needs, when they are so disparate? You mention that air-source heat pumps, as part of a good mini-split system, have become more capable during very cold temperatures, and you're not wrong. However, the way they achieve this is through a dramatic increase in the amount of energy used to defrost the coils, repeatedly. I was really hoping you'd show the power utilization graphs from a zone six or seven system, because an air-source heat pump in those locations uses a LOT more power, when it gets down to normal winter temps in those zones. I like the idea of one or more air-source mini-splits, paired with a very well-built masonry heater; the best implementation of the newest technology and the oldest technology. With a right-sized solar/battery array, this solution works very well for zone 6 or colder. It would make no sense at all in zone 3 or warmer.
So much in this comment I appreciate, I’m going to respond separately to some of it.
What do you mean a very well constructed masonry heater?
ruclips.net/video/iQ_HR4hAqhQ/видео.html
In this video I go over the problems you have to solve for a well designed solar and battery without wasting money
I go over 3 problems
1. The night time problem
2. The winter time problems
3. The snowstorm problem
But I didn’t really talk about the snowstorm problem very much. Basically the snowstorm problem is what you’re referring to, how to you get through the 2-3 weeks a year when solar and battery becomes exponentially more expensive as a backup power source.
There are many solutions to the snowstorm problem, we’ve defaulted to 1 which is a automatic standby generator, because it can get us both through a snow storm, or any spike in electricity we weren’t expecting, and it can double as backup in the case of an inverter or Bms failure
I tried to make the point in this video that geothermal is cost effective past climate 4-5 and for Offgrid it’s cost effective even in climate 3 in some cases
@@alanknudson8774 - If you're not familiar with a masonry heater, they are remarkable structures typically built as the core of a home. They are massive, meaning they have a great deal of thermal mass. They burn a relatively small amount of fuel (wood) very quickly and at very high termperatures. Those temperatures flow through a series of masonry tunnels or chambers, heating the thermal mass and discharging far less of the heat created out of the flue pipe than a conventional wood stove. They have no moving parts, typically only need to be fired 1 or 2 times per day, (no tending) and are an essentially infallible way of heating any home that was designed around one. If you have dry wood, you will be warm. You mentioned in this video that you can't always rely on propane or natural gas deliveries. The same is true of the gas or propane for a generator, which has a lot of moving parts that may fail during a "snowstorm".
I would also mention that in certain parts of the country, there is insufficient solar potential for much longer than 2-3 weeks. It's more like 7-8 weeks, in some places. Ask me how I know. :)
You can do geothermal DIY... if you're inclined towards that sort of thing. $5700 for the equipment to do a 4-5 ton geothermal system from MrCool. If you're building a new house, just do the loops when you're doing the foundation work.
A lot of people are not very inclined for it, but HVAC is actually far simpler than people think and the new systems are so good for it.
Speaking of gas... there are on property sources of fuel gas when you're off-grid with a septic tank.
Excuse my ignorance, but why is cooling being ignored on the graph, especially in Arizona? Doesn't it use the same system to get similar benefits from geothermal in summer?
Cooling is an odd duck for geothermal.
And a lame duck for offgrid
So i ignored it for the most part.
Essentially, mini splits outperform geothermal aggressively in cooling mode for most climates like Arizona, so there isn't a benefit to cooling with geothermal versus cooling with a mini split generally. (not always the case, but generally)
Geothermal systems, tend to lose efficiency over time if you get the loops too hot, it pushes the moisture away from the loop because of the heat which lowers efficiency which causes the loop to heat up etc etc.
For an offgrid home, you have plenty of excess electricity in the summer generally, because of the Day to night problem and the winter time problem, covered in my earlier video "how not to waste thousands of dollars when designing your offgrid home"
So effeciency gains in summer are minimal, and the value of those gains is nearly 0 for an offgrid home running on geothermal. All of the gains tend to be in heating in the winter instead, or producing domestic hot water in the winter etc
hope that helps, i'll try and explicitly show those calculations in our next video on geothermal systems
@BatteryBuilds-p5x yep that helps, thanks!
That's a deep point and telling, about the lack of expertise in the hvac industry. Best route for a homeowner is usually to get an engineer with some experience with similar systems, and pay them to sign off on the design, talk to the inspectors, and check the installation via startup and diagnosis. I agree that done well, geo is an excellent choice where heat or cool needs are at 5 btu tonnes or more.
Yes that is biggest problem in residential building, designing before building is so rarely done, commercial build has to have everything in BIM and every screw, nail accounted for. residential build you can even see moving walls mid build lol. I like "shallow" geo in areas with high water table, that way construction is a lot cheaper with same performance.
Unless you’re using geothermal for thermal storage….
😉
Sounds like you need to get started with air-to-water!
Spacepak’s are hot. I’m a big fan actually. Never used them yet, but I’m trying to this year sometime
@@BatteryBuilds-p5x Wish there was a love button for this. Please make sure you reach out for our support along the way!
The problem is trying to do it on a house by house basis. The underground infrastructure needs to be done at larger scale. Individual houses should just connect to that shared infrastructure. At that scale, it's cheap.
I suspect I live far enough North (Climate zone 7A) that air-source heatpumps would have a huge drop-off in efficiency during the coldest week of the year.
Maybe directional drilling can help cut costs: I do live in oil country. My understanding is that the biggest expense for a ground source heat-pump is actually burying the piping.
burying the pipe is a big one, the distribution system (ductwork) can also be a bit more costly, as many geothermal systems run lower temps, and higher CFM so bigger ductwork.
Also the geothermal heat pump tends to cost 50% more than a normal air source heat pump if not more so a few items besides drilling to consider when doing geothermal.
a bit more labor too, depending on the setup, for the pump station and if you set up a desuperheater especially
@@BatteryBuilds-p5x I may have found a loop-hole for the ductwork: many systems are over-sized, especially if you upgrade the insulation during the upgrade.
Great content. Counter point for you to consider is air source heat pumps keep getting cheaper and more efficient.
A 1 ton mini split can be purchased for well under $1000 these days and the price keeps dropping.
Also, with the switch from r410 to r32 they have picked up some efficiency.
Additionally, pv and battery storage keep dropping in price.
I wonder if 5 years from now geothermal will still be competitive compared to air source, for off grid living
Mini splits are interesting… very cost effective often.
Most are made overseas, and with the new tariffs will likely go up a fair bit in pricing.
The cheap ones generally can’t handle cold climates with high efficiency. So I’d say you get a lot for paying for a nicer one.
Compared to geothermal they lose out as the house and the loads get larger. But for small houses, low loads they’re ideal and super effecient!
I think geothermal going to gain ground mini splits in a lot of markets. Basically mini splits destroyed geothermal sales and geothermal is adopting mini split technology going forward should be quite interesting.
Mini splits struggle to get good air distribution, for higher end homes that’s an issue as well. Curious to see how it evolves going forward myself
The ground gets warmer the deeper you dig so I have always assumed that running costs for GSHP would be cheaper if you could just dig a deep well to the water table and draw water up and through a heat exchanger and then back into the ground some distance away. I don't see this suggested so is this a regulation/code issue or what ?
Its not against regulation where i live, it is simply not cost effective generally.
Unless you needed the well because your house was offgrid to begin with!
Water wells are often 4-10x more expensive per foot than geothermal wells, because you drill it bigger 6 inch generally, then you case it with steel or pvc which is expensive per foot, then you backfill and grout the hole outside the casing, then you put a well pump on a drop pipe down the hole to pump it.
So there are many situations where open loop works, but the easiest one is, you already need the water well, and its relatively close to your house
Then it can be magical
it does sort of ignore what i think is one of the most under explored benefits of geothermal for offgrid houses, closed loop systems aren't power sources, there really really large batteries
so you can store heat or power in them in a way that simply isn't possible with lithium batteries
We have an old air heat pump system as we live in zone 3. Works ok when the temps are moderate, but not so well when it gets well below freezing.
Something I have contemplated to help boost it some, at low cost is the following: Bury a few large copper pipes deep in the ground (in my area, 9 to 10 feet or so). Into those pipes will go highly conductive powders, and some non copper reactive liquid. Then copper tubing, which will be converted into "heat pipe" type tubing will be wrapped around these copper pipes, especially at the base. As the tubing and pipes get closer to the surface, they will be highly insulated.
Anyways, I would probably flatten out this tubing and try to make it have physical contact with parts of the outside condenser unit.
I can't do this, because we have too much shade on our property, but Solar Air heaters are really criminally under used. They are relatively easy to make and install, and can be made quite inexpensively. If you do it right, it can really cut down on the amount of daytime energy you need to use, whether that is electricity, propane, natural gas, wood stove, etc.
Currently we are experiencing a somewhat unusual cold snap with lows into the mid teens and a bit lower. To help my heat pump out, I've put a 15" smokeless fire pit/stove nearish the condenser, put a burn barrel over the top of it (upside down, the bottom has some vent holes on the top and on the sides), and then I wrapped an IR reflective foam loosely around it all (with plenty of space to allow the fan to get enough air and to not over heat the condenser).
Some of the wood is just waste wood from my yard that I can't use in my wood stove because it would create too much creosote, it's too small, or the like. Yes, it is somewhat near the house and may not be fully legal, but I consider this set up much, much safer than an inside woodstove with the potential for chimney fires. Sparks cannot escape this system, and there is no chimney. No, it is not very efficient, but if you're mostly using yard debris, that's not really an issue.
Solar to air heaters have their place, there in my list of technologies we need to analyze as alternatives to what we typically would use.
Heat pipes are too.
heating the air near your compressor with waste wood is a decent way to go, the hard part being that much of the air is going to escape. But it is clever as a way to boost output only when it's cold outside.
I have a fascination with modifying heat pumps to make them multi-source. Like increasing the heat intake on the compressor.
One way you could perhaps improve your setup would be to bury the fire source, so that you're looping in the ground around it. So more of the heat your generate is "stored"
in a cold snap, the worst load condition is generally right before the sun hits your windows. So maybe by having the stove buried, with air pipes through the ground around it going to the compressor, or even rerouting the compressor refrigerant line to go through the hot dirt battery before hitting the outdoor unit, would allow it to use that heat through the night.
Ideally you'd end up with 13-14 hours of extended efficiency in the night time hours, in theory at least. Would be a interesting use case, thanks for posting your ideas, they're really interesting for me to think about!
@@BatteryBuilds-p5x The combo of the aluminized/IR reflecting surface of the foam surrounding the condenser unit and reflecting the IR to it, and the fan on the condenser unit that sucks air in and up, does help more heat to get to it, but yeah, it is not ideal, because a lot of heat is being lost at the top. Another IR reflector above the fire pit/stove and burn barrel combo, and angled down towards the condenser unit would help a bit.
I'll have to think about your suggestions a bit. Thank you for the reasoned and thoughtful reply, for now.
Cheers
I think geothermal only makes sense if you are in extreme temperatures where an air source would have challenges or be incapable... like below -22F (that is about the limits of the modern air source heat pumps).
I think there is room for "geothermally" supporting air source heat pumps, though. For instance, if you had a hole, you could actually have a cooling radiator in the hole and fill it with an inert oil, like mineral oil. Enclose the hole with something sealed and ensure it has fantastic ground contact. Yes, it could get saturated, but it will dissipate with time.
Another good option is using VRF Heat Pump setups. We don't really have fully integrated setups today, but I would love to see these where we incorporate out water heaters (these do exist), our refrigerators and freezers, and more. We have these various heating and cooling demands all around our homes and we can move hot to cold in any of them.
Inverter technology has made closed loop geo largely obsolete. But once the pipes are in the ground you can not compete with an INVERTER driven geo system. The problem is water to air or water to water has 1 inverter driven system on the market .
It’s a great point.
Inexpensive Inverter systems, drove both the very high efficiency and the very wide range of outputs for mini splits. It gets rid of fans and recirculation pumps
This is the 1 reason geothermal has been lagging generally the last 6 years approximately.
When you bring inverter driven components to GEO the math comes back hard for geo except when loads are quite small.
Variable speed geothermal can accomplish 6-8 COP ranges in some cases for Offgrid in the winter heat pumps. So only as loads get smaller and smaller does geothermal become less and less effecient compared to Air source variable speed systems
Inverter-based ground-source water-water heat pumps are extremely common here in Scandinavia, there's tons of them. I'm surprised it's not the same in the cold parts of North America. Air-source heat pumps are great if it doesn't get colder than 10F or so but once it starts getting colder than that, their efficiencies really drop. Having access to the geothermal heat reservoir and letting a ground-source pump work at a COP of 5-6 throughout the cold part of the year will, long-term, pay off the installation costs.
@patrikj government funding for geothermal fields caused a boom about 15 years ago. Since then the few companies specializing in geothermal water source equipment just didn't invest in manufacturing upgrades . And now with time of day energy harvesting / storage you can run an air source during a 20 F day and use the stored 160F water for heating at night. So new fields are pretty much a dead concept. From an offering to the potential homeowner anyway.
Interesting, factoring battery cost into comparison makes sense, thanks for pov
It’s kind of the only thing we do here :)
Geothermal is an excellent method of heating and cooling if implemented correctly. The problem that I see is that we want it cheap and easy. I've reviewed a lot of systems and have found their implementations to be questionable at best. Take a look at what they have done in northern Europe and then decide. But be prepared to spend because you are looking at 10+ year pay backs.
Air source will never compete with ground source (geothermal). Geothermal is always more efficient all year round for both heating and cooling. Whether its 80, 90, or 100 outside, its still 65 in the ground (Georgia). Whether its 40, 30, or 20 outside in the winter, its still 65 in the ground. The only time an air source HP is as efficient as a geothermal system is when the temps are mild and you need neither heating or cooling. That's the beauty of geothermal, the ground temps are in a range (in north America) where the heat pump is most efficient for either cooling or heating. For air source, you need cooling most when it's hot, but that's when air source is least efficient. Or in the winter, when it's the coldest ouside, that's when you need the most heat, but that's also when an air source HP is least efficient.
As for efficiency, air source mini splits or ducted inverter heat pumps never get above 16 EER (btus per watt) when it's 95 outside. Most at 95 deg and full load don't get above 13 EER, only small 6k btu mini splits get to 16 EER. A geothermal system can get over 22 EER with loop temps at 60-70 degrees. With the 30% tax credits geothermal doesn't cost any more than an air source system, so unless you don't have the space for a horizontal loop and can't drill a vertical loop, geothermal is always better.
Re interruptability: In 33 years, I have NEVER lost my gas supply. I have lost my electricity countless times.
Your heating system still won't work without electricity. You need a electric blower to move air through a furnace or an electric pump to move water through a radiant system. Only heater that uses no electricity is a wood stove. Gas won't save you in a power outage.
How much land do you need to chill to heat a home? I see the possibility for a road of houses being able to freeze their whole plots inc mains water and drains
great question. Most houses have 100' 150' trenches per ton of hvac load.
However, they only use a fraction of the soil temperature. Meaning most of the heat being pulled out of the ground is within 3' of the trench, past 3' a temperature of 5 - 10 degrees warmer or colder than the surrounding soil is typical
Although in northern climates, where you heat a lot and cool a little that cold pocket gets bigger and bigger each year. Which is a problem in sweden particularly. It makes for a great thermal storage system but has issues when you're using soil a source rather than long term heat storage, (meaning you replace the heat you take out on average)
Using propane or any other fuel that someone else provides from off site, is not "off grid". All of the extraction, refining, production, and distribution of those fuels are very much "on grid".
Offgrid as I’m using it in the video would be something like, how long can you last without outside intervention.
So propane would be fine as an input, but how long can you really go until you need refilled?
Offgrid as your defining it, would be can I survive or live independently for all time without outside help.
Would be pretty awesome, much much more difficult to achieve and likely not what our customers actually want.
@@BatteryBuilds-p5x Understand. There's ideal, then there's practical. I'll be the first to admit that I've had dreams of having an entire propane tank trailer, full, on my property. Not for the primary energy source, but to fall back on. Should last an entire lifetime that way lol!
Geothermal makes sense for cooling in northern areas, but directly, not through running them a heat pump. Air source equipment is so much cheaper for a small off grid house, that geothermal heat pumps don't make sense. But what I'm going to do is that every time I have to dig a trench for some reason, I'm going to run a ground loop in the bottom of it. In the cold spells in winter in the winter, I'll use that to pre-heat air passing past the air source mini split. The rest of the time, I'll use it keep my water from from freezing, and minimizing the night time dip of my eventual greenhouse. Use a wood stove when I'm awake, and a propane hot water feeding a radiant floor when I'm not. My guess is that I'll find out that it is better to cut firewood, then to pay for more propane to run the generator or put in more panels. It is just too cloudy in Northern Idaho!
Geothermal in northern Idaho could be ideal. Especially if you have a septic system. It’s not always a good idea, but running geothermal lines underneath a septic leachfield or alongside a water well line feeding the house are often very good ideas to save money.
Open trenches like your saying are also a great idea many times.
The greenhouse heat load can pair well with the house system. I’d say if you’re already looping and pumping, you may as well use the heat pump as well!
Geothermal is complicatet, in my country (Denmark) geothermal is actually earth heated by the sun in the sommer time so not heat generate by earth. And we always do it in "lines" 3 feet in the ground with 1 to 2 feet in-between.
@@alanknudson8774Why is it complicated?
Me listening but not looking at 0:54, “just a second sweetie dad‘s going potty.” 🤦♂️
Hahahaha
Dad life - moms got my back
never ran out of gas. regularly lose power during storms multiple times a year. reliability is NOT buying a heat pump because they depend on electricity.
Certainly depends on the local weakness you’re optimizing for.
Electricity is usually less reliable, in Offgrid ours has gotten to be pretty good.
Especially with reliable backup generators for storms etc.
When I say reliable, I’m meaning if you had grid wide, society wide shortages or failures.
Not a great measure of likely use, just a piece of mind feature many people want when it’s available and they can afford it
Solar with battery, backup generator, bam
Your illustration at 1:37 is correct for a cooling cycle, but your explanation is backward. When in cooling, the metering device creates a pressure drop causing the refrigerant to "boil off" and absorb heat (like a kettle on a stove boils). Compressors compress low temp-low pressure gas to high pressure-high temp gas. Heat rejection outdoors causes the refrigerant to condense back to a liquid and repeat. A heat pump adds a "reversing valve which swaps the coil function of heat rejection to indoors and heat collecting outdoors. Yes, i do this for a living. This is a basic explanation of a refrigerant cycle. Addind water loops indoors, outdoors or both complicates the cycle a bit. But its still basicly the same principle. Your just changing where your heat comes from and goes to.
good point! thank you very much for that. I'll see if i can find a replacement image
Basic principle, cold absorbs heat.
How does the cost change for a horizontal loop instead of vertical?
Vertical is more expensive generally.
We pay $21/ft of borehole plus a mobilization fee of $3500
We typically need between 100ft to 200ft of borehole per ton.
So for a 3 ton system you’re talking $6300-$12,600 plus the mobilization fee.
Backhoe is normally $9000-$10,000 and can be self preformed often
Vertical is typically used when there’s land constraints and horizontal when there isn’t, or during new construction. It can be as cheap as $7,000-$8,000 in the right circumstances (backhoe on site, or installed during over-ex and backfill, to save equipment and people trip to the site)
I think the wrong chart is showing at 6:36
You are correct... thank you very much for pointing that out, i'll update that when i get home later this evening
We lets go over the pluses. Approximately 70 percent of energy is low energy heating cooling, for the cost of a fan, pump , radiator you can keep the house at the temperature of the earth 20 ft down. Well above freezing well below comfort. Now add a heatpump you get comfort at very efficient rates. Cons , burning methane to power generators and send that energy down the line costs 8 to 40 cents per kw to run an air heatpump at that is cheaper. I smell government interference and price fixing probably benifiing companies and voters with cheap electric power
@johnschneider931 I have created bids on several commercial geothermal ground source heat pump systems in my career. Most of the cost differential between air source and ground source comes from digging the holes and installing the pipe. If there were a cheaper way to dig holes and bury the pipe, then ground source heat pumps would become king everywhere there is enough land to put the wells.
@@peterirvin7121 another big concern is realtive effeciency
Geothermal has been losing ground in relative efficiency compared to Air source units in recent years mainly form cheap variable speed ASHP. But geothermal is gaining ground by switching to variable speed, and by innovations in the drilling side that are starting to change the game back in its favor.
PS. rate hikes make it better for geothermal too, so see that coming in the future as well
Have a look at heliotherm or other R290 geo thermal heat pump.
I love Nibe, some neighbours have a nibe glycole/water ground heatpump
Also have a look at hydronic underfloor heating, that is a game changer if you want to go of grid. With the water loops in a thick screed layer, it will store the heat energy and slowly release it into the building. Depends on the insulation and outdoor temperatures a room temperature drop of below 1°C over night without starting the heat pump is possible. You charge to floor in the day while the sun is shining
I’m a big fan of hydronic. And concrete screeds in general.We’re trying to permit a house that heats and cools with radiant next month, will definetly have videos to show how it goes
Most geothermal is just a ripoff. Local companies wanted $10-14k to replace our old unit. Replaced it myself. Unit, tools, fittings, everything $2700 with beer money left over.
Correction, most geothermal installers are ripping people off. The equipment isn't any more expensive, it's just the installers charge waaay too much.
STOP HEATING AIR. Hydronic system + separate ventilation is much better and effective solution.
I love hydronic, especially for Offgrid!
We’re working on a house plan now that uses hydronic for heating and cooling.
I have a video on Corbett lundsford’s home performance channel that is a clip from a consultation he did for me on how to manage erv and air flow on a hydonically heated and cooled house
Where I live we don't heat or cool.
The sweet spot, coastal regions are so much fun.
7 solar panels and a car battery is about what it takes to go Offgrid
@@BatteryBuilds-p5x seven by 100 watts? so 700watts total, during a sunny day, some days cloudy. And in case of a serious storm the solar panels removable to shelter, or protection put on top to prevent damage. Ideally, in the future a machine should roll out the solar panel protection like a DVD/CD cassette disk can go in and out of the computer.
Why do you say geothermal instead of ground source?
That’s the terminology I’m used to in my area. ground source heat pump is definitely more correct though
@BatteryBuilds-p5x Do you use the term brine for the liquid in the ground loops even if it is water or glycol?
Almost always yes, glycol water mix 5-10% or at a minimum to allow loop temps to drop below freezing temperatures
How can you suggest that a heat pump or ANY electrically driven device is better for off grid? When solar panels are your only source of electricity, anything you burn is a much better source of heat. Propane being the most available with little intervention to maintain heat with little or no electricity or human input (loading wood in a stone) which would be cost prohibative if done by PV panels inverters and Batteries
For a cabin, or a small seasonal use house that is the case. Solar is required, but something like an ecoflow delta 4 is big enough.
However once you’re talking about full time use, you need the inverter, the solar and the battery. For cooling, lights etc.
So the question becomes, what’s cheaper? Propane across time or solar and battery across time.
A hybrid approach is often the cheapest, propane and solar together
However, if you wanted a “doomsday” Offgrid house, where propane deliveries would have stopped
Or if you want to build in an area where propane delivery isn’t a viable option
Or if you’re load and runtime in propane was large enough ($1,000-$2,000/yeat)
Then geothermal plus solar and battery start to have a payback compared to propane, plus a propane tank for heating
In ideal scenarios you'd want dual source and one that doesn't have to have fuel supplied. Since a geothermal heat pump usually has a COP of about 5 it means the amount of heat you get will be about 5 times a resistance heater. Then on too of that you'd orobably want a wood stove since in a situation where you were cut off from external inputs it's difficult to refine your own propane but easy to find wood around.
The next question is if you could run a propane generator to run the geothermal heat pump would you actually get more units of heat out of the same amount of propane?
So lets say you wanted to figure this out. If you have 8000 cubic feet (1000 square feet * 8ft ) and you want to heat from 20F to 72F you need something crazy like 55000 BTU.
An electric resistance heater will put out about 3.4BTU per watt meaning you'd need near 16kw of heaters.
A geotgermal with a COP of 5 will do 5 times that amount so you need 3.3kw to output that much heat.
A 90% efficient propane heater will use about 0.67 gallons an hour to output that amount of heat.
A 4kw propane generator at 100% load runs at about 0.67 gallons per hour.
So in this case I would probably prefer the geothermal, battery backup with solar, and small generator which can run if the solar battery backup drips below 20% capacity to top it up a bit and keep the system running.
If you were running ab air source heat pump that had a COP of 3 at that temperature swing it would make more sense for the backup heat to be a propane heater directly as the heat pump would need much more fuel to keep the place heated but the trade off being you now don't have the generator which can be used for things other than heat when heat isn't needed.
@@Snerdles There is also a big factor, I haven't covered yet on my channel. Which is the fact that you need almost in every case, a back up generator. So you're not paying for a generator or not, you're only paying for the incremental fuel cost of the generator.
I didn't explicitly state this in the video, but it's the reason we generally design for 24 hours or around there of battery usage assuming no solar. Because we're relying on a generator for the days outside of that window, or even abnormal changes in energy usage like a long thanksgiving party, or a broken compressor running more than it normally would.
one of the very common "high use" scenarios is actually a customer leaving something on, like a space heater which is our worst enemy in an Offgrid house, or not changing hvac filters and their units start short cycling as a byproduct
So variable power generation from gas or propane is very valuable and expensive to replace without big batteries and home load control and monitoring to identify failures and alert the customer or shed that load before the customer has to respond to it, or risk losing power
@@Snerdlesyou forget that with an efficient setup the waste heat from tge generator is also used, making ut always more efficient to run a heatpump because you still get the heat from tge propane directly, you can just multiply a portion of it
.........and of course...the HEAT will Kill you First!..........although 1.5 degrees (C) average temperature increase was predicted by the year 2100...well that happened this year !!!!
......its accelerating !!!
Where I am from we have 130*F temp swing between seasons and a 6FT deep frost line. Air source is less than useless in my climate. For heat pumps Deep geothermal is only electric option.
Wow - where is that?
@@tcreamer710 Alberta Canada!. at 1000ft we have a 60F ground temp. perfect temp for geothermo. But we need 10ton systems when its -40*F outside
@@tcreamer710 Alberta Canada. at 1000ft deep we have ground temp of 60*F. We need 10 ton systems when it -40*F outside.
Geo in the ice is incredible. Love my Canada people.
Heat up there is a way bigger deal than southern Utah for sure