I have installed ductwork for 32 years here in Northern California. This guy did a nice job of explaining things correctly. To answer some problems- if you are getting too much air in 1 room and not enough in another room you could add balancing dampers in the ductwork to divert the air into other rooms. Also a big thing he talked about is too small return air to the unit, this causes many problems. 1 is the unit may freeze in a/c mode in summer because the unit is starved of air over the coils. He brought up static pressure. This is an issue with how the system deliveres air evenly. Proper sizing of ductwork helps delivery of air through out the home. Stepping down in size the further you go down the line is key to proper airflow. Hope this helps some of you. This guy is spot on here. Good job
Paul , I have this issue on my new home , CFMs were tested in each room and it’s higher on one area and lower in another but still above the CFM plan However, one room is hotter in summer and colder in winter I asked for the engineering plans to be relooked at and ensure loads and cfm requirements are calculated correctly… we’ll see what they say
@Victor Cruz installing damper collars is easily done by a pro. Using the registers only makes it noisier in the room. The extra heatload in some room's could be from what's in the room generating heat. Can lights, tv, computers... Lack of window coverings on the sunny side of the house... All easily fixable.
@@VictorCruz-wn8tz Good luck with that. Unfortunately systems are rarely installed prior to closing up walls. It would be nice to be able to run those flow numbers prior provided that ALL condicalculations. (Insulation, window effcy, sun, etc) are set forth in the load calc.
👍 as a former Licensed Sheetmetal worker , estimator, business owner, and heating design, this man explains it well without going into excessive detail.
A few of years ago I got a new AC. It was supposed to be a 4 ton unit for 2200 sf. Another company came out for a free yearly checkup and I was informed I had a 5 ton unit and my ducts were not adequate. He also suggested a second return air. I had 4 estimates from 4 companies who all pretty much said the same thing. I had the first company do the job. 9k for all new ducts and additional return air. What a difference. It’s very quiet now and the whole house stays cool. Before, the living room for example would not cool down during the day with company over. That ductwork costs more then the AC install. But, I should only have to do it once!
Having enough return is an extremely important part of a properly running air conditioner. Also not using restrictive 1 inch pleated filters they cut airflow substantially.
Perfect explanation of HVAC. I’m a plumber of 30 plus years so I’ve seen some duct work. If new homeowners and about 95% of home inspectors would watch this video a lot of new homes would be left sitting! Several years ago my Dad hired in the side a couple of my sisters X buddy’s to install a new furnace and a/c unit which he purchased and of coarse he upped the tonnage which he thought would be better. Well after the install the unit which was a Lennox began having problems. Well of course he had a HVAC contractor come out and they said they couldn’t find any problems. I went and just put my eyes on it and began doing some test just using a thermometer and common sense. After doing some thinking and calling my buddy which is a HVAC company owner and explaining the situation and giving my thought on the problem he told me your exactly right. The unit was starving for return air with the unit being upsized. So I called my dad and told him I’d be over the following weekend and we can address the problem. Thank god I got there when I did because he had already drew out lines on the walls where he wanted the return vents and had started cutting Sheetrock with a razor knife. I stopped him in his tracks from cutting any further and told him we’re not going up into any walls we’re gonna go through the floor! Short story long we finally got the returns in and the unit has worked fine ever since! The contractor world needs more Professional People like you in it!!!
I have a 1200sqft 3/2 and a 2.5 ton unit that is 3 years old. The air handler is in the attic, and I'm replacing the entire duct system from the 70's by myself. Your video has been the most helpful I have found yet. You even used the same size house/HVAC unit I have as your example. Praise The Lord, Jesus Christ.
As a retired engineer (BSEE) I have to say that the duct work IS the weakest link, and although the airflow dynamics can become quit complex Mr. Griffin provided an excellent, easily to understand explanation. Einstein quote: “If you can't explain it simply, you don't understand it well enough.” This is who I would want to do all my duct work service.
Always check behind your plenum box and make sure they sealed the area off from the attic if you have a closet mounted blower! Paid $8k and found the installer never sealed the back 4” off so I was pulling dust , dirt, and gross outside air into the closet into the intake and through and out the duct work! I fixed it myself because I’m so sick of being scammed by AC guys.
same here. my guy showed up smelling like weed and the plenum wasn't even square to the point of having a 1/2 inch gap on one side which he "mastic'd up". I had my drywall contractor come behind him and seal between the plenum and the attic. He also created a flow unbalance and one of my bedrooms gets hardly any flow.
Well you just disappointed about 75% of home owners. Unfortunately builders and many home owners use cheap mechanical contractors for residential the majority of time. Therefore you get low skill labor at a a good price. Get multiple estimates from reputable companies and ask to see their work. If they can’t show you photos they don’t take pride in what they do. Doesn’t matter if you spent 20k on your new system if it isn’t installed correctly. Do your research on companies. Ask to see their work. If it doesn’t look good, it’s probably not. People that do good work take pride in their craft. It should look clean, not like a rats nest, or bomb went off. It should be sealed. Trash shouldn’t be left in the attic or basement etc. quality mechanical contractors are definitely out there but it’s up to the home owner to do their research on the companies they hire.
Thank you. You earned my support. I’m pretty sure you solved my house heating issue. I probably have a 30 foot trunk with a 90 degree angle all the same diameter. The two rooms in the end are freezing.
Thank you for this video! Wow, my home has all of those issues…trunk not stepped down, rooms warmer than others, same size (6”) duct going to every room regardless of size, supply coming off the end of a trunk. I’ll be calling for someone to review it this month!!
The biggest issue for indoor air quality and occupant health is actually duct leakage. Even brand new duct systems leak quite a bit. Our brand new, pretty well done duct system actually had 120 cfm of total leakage. We had aeroseal seal it all up for us. Everyone is breathing contaminated air, pressurizing, or depressurizing their home with poorly sealed duct work. No good. Contractors building building's envelopes and mechanical systems are directly affecting the health of the occupants. In my new house, I needed to add ventilation because VOC's were too high making me not sleep well and our house prior to sealing the ducts was pulling in attic air and pressurizing the house. There's a lot of data now showing indoor air causes lots of chronic health problems. It's time for A/C guys to start paying attention instead of just throwing in a single speed A/C with a fiberglass filter, no ventilation, no dedicated dehumidification for mild months, and etc. Into homes and not thinking anything of it.
When we come to your home and tell the homeowner what needs to be done on a new home install or changing out the equipment in a older home,it all comes down to what they can afford. As far as duct work it’s code to seal all the joints but sadly not the designing of the system.its a lot of hacks out there.we can sell you high seer inverter systems with high in air purifiers,ultra violent lights,humidifiers,ERV systems but the majority of people can’t afford this level of job.
Yeah like on mobile homes. The plumbers, electricianz, and AC guys drill holes in the sub floor and dont seal. So literally a bunch of seals not sealed let alone ducts are never installed correctly.. you need the right tapes, spray glues for the tape.etc. just did our home and we had a basketball sized hole in the trunkline where a duct used to be.. they had it capped but it was just tape and over time just fell to the floor... Lol
I rented a 5000sq ft building for my restaurant, was having trouble with the air flow. I was shocked when i went in the attic and see what the previous rented had done. 2 4 ton units main duct work was about 8 foot long, each unit had 12 vents. but they used 12 flex to all the vents and tapered down to 6'' about 3 foot before the vent. this caused NO AIR FLOW. not to mention the power bill was 1200 a month. i fixed all the ducts. and air flow is good and power bill is down to 550.
I’ve got an addition I’m running duct to and I’ve gotta run 4 more vents. About 30ft away for all of them. Might scrap that idea and do a mini split for it
This is such a critical video. I think I'm going tour some new open houses in my area and see if the ductwork is up to par like the points you made in this video, and then find out who the HVAC installer is for those properties!
@@NewHVACGuide Will do! Just the fact the you're protecting people's investments is awesome because nothing more I hate is spending hard earned money only to be disappointed afterwards.
@@NewHVACGuide You should do a video on return duct strategy & placement. I went round & round with the scabs that installed my mothers system back in 76 about return ducts. They should have louvered vents with 1 high and 1 low on each floor so that in winter they suck cold air into the furnace and in summer they suck hot air into the A/C system so the system can adjust the house air pocket to make the T-Stat work less often to maintain a constant temp and make the system cheaper to use. They put the only return duct in the downstairs floor and in summer the upstairs temp was 45* hotter than downstairs. 25 yrs later I got the house and cut the wall open and added a return upstairs and evened out the temps myself.
You bring up a good point. Makes me wonder if sometimes things are not done properly because they are trying to keep the cost down as much as possible or if some folks are just simply lazy?
Just finished installing a 12 ton commercial unit I got off of eBay in my 1200 sq ft bungalow here in northern Minnesota. Haven’t turned it on yet. My good friend told me that 1 ton per hundred square feet of living space is a good rule of thumb to use for sizing estimates. Is this correct?
2:10 Those step downs aren't for the rooms at the end of the trunk line, they are for the branches BEFORE the step down. If the trunk doesn't reduce in size all the air will pass freely to the last vent.
This explains my attic system servicing my 2nd floor. The largest bedroom has two ducts and good performance. Those ducts are at the end of the plenum. Bath/hallway/smaller bedroom also OK in that they are balanced temps. But there is a 3rd bedroom end of hallway often too hot or too cold. It has the longest duct run. And unlike the other bedrooms, two walls face outside and lack of insulation is an issue (house is over 80 yrs old). I'm considering adding a 2nd duct run to that room.
Good video. I have 6 inch lines for rooms. My question is return air will be 6 inch as well. Can I install 4 " vent for washrooms? Approximately 50 sft.
thank you, sharing your knowledge... U explained simply (& Logically) ..Am "simple home owner" (not in industry) w/ desire to know: "should expect of duct work": design & function
Plenums with duct work off the sides work good as long as you keep your take offs towards the cap and use volume dampers at wys for each supply to vent. And alway as Mr Griffin said step down size at transitions Great video 👍🏽
I have a very centrally located electric furnace. Can I come out of the plenum on all sides like a Medusa? I don’t have a particular direction I need a trunk.
My Ductwork in my 2nd floor blows massive velocity cold air in the open area & hardly any velocity in the three bedrooms. There are air vents are over my downstairs & it freezes us downstairs. Whereas the bedrooms are 6 to 10 degrees hotter. Can the bigger ducts go to the bedrooms instead?
I have a 25 year old home. My master bedroom doesn’t get enough heat. It’s super cold. I cleaned the vents already. Idk what I can do about it. Pls suggest
10 years ago I had round hard ductwork installed and it’s cooled the house better than ever. Recently I called a company to check for a leak in my unit and they ended up sending out a couple guys to give me a estimate on a new system. We had heavy rain the previous day and they told me they couldn’t price a new unit without new ductwork as it got wet and had water inside. The ductwork was installed with hangers and may appear it’s laying on the moisture barrier but it may just be the insulation that got wet. I don’t see how they can tell if water is inside. It’s a large heavy duct . They left without giving me a quote because I declined new ductwork. What do you think?
I have a Mobil home ac vents are in the floor. ? Is should the return air be up high over the coil or should it be in front of the coil I ask this because when I got the trailer it has two returns 16/20/1 direct above the coil. It’s a 4 ton
I had a mehane leak. They put silver tape around and suggested a bird's nest may be in the pipe exiting at the top of my roof . I cannot see any damage to this small pipe from the ground but I am nervous . They sealed off the leak but I am elderly and not able to climb on my short roof .Can I call the fire dept. for advice ? I spent all my $$.on getting the motor cleaned which is what HVAC recommended. I didn't have any issues , no whistles, no shutoffs at the thermostats or alarms . Any suggestions ?
I have the HVAC system in the attic in a new 2 story house. I have a duct that is not routed to any room, it’s just blowing cold air into the attic. Is that normal or the contractors just left it incomplete?
Thanks for the video. I have a question I hope you can answer. We did a remodel on our kitchen. There was a Half wall that created a small entry space from the front door that we had removed to enlarge our kitchen. This wall had a hot air duct that pointed into the small entry way. After the renovation and removal of the wall, that same vent now is open and points down into our basement area. Can I remove that since there is already a vent into that room or should I leave it alone? thanks
I’m a hvac apprentice and I’ve been doing new construction duct work install for the past few months. Can I make a career out of duct work or is it just a good start?
If you have flex ducting can you installed a and if not do they make something to where you can just take the duct off of the supply and just cap it or something
My house is built on a slab. There's a crawl space/attic. However, the ductwork is in the ceiling and walls. How do I find out what ductwork I have? I don't know if it's suitable for a 2 or 3-ton system.
My ac broke last summer. Now I need to replace both AC and my ancient furnance. Only to find out the duct work is too small for the house I have and no matter how good my systems are, it will struggle to cool the 2nd floor.
I had my basement finished in 2003. I had it stated in the contract no duct tape. When I saw the hvac person using duct tape I told him to stop. He argued with me saying it doesn’t matter if the ducts leak, the heat is still going into the house. I told the general contractor to find a different hvac person. Too bad I didn’t know about mastic at the time. I should have specified that. But at least all the new joints have foil tape.
I have a 5 legged spider to deal with. Definitely looks like a DIY project by previous owner. Big, fat 9 inch ducts with asbestos tape. No HVAC company will touch it so I gotta do it myself. I'm hoping to find some sort of cap for the extra holes and commit to a main trunk line off of the remaining take off. Then will use flex duct to reclaim some ceiling space.
I have a 3500 sq ft house, two floors. The furnace heat comes out only from the left side of the house. I checked the duct work, both sides of the house come out from the same duct, I am confused.
Is there way to determine if your existing HVAC system is big enough to add room vents to? I have a basement that was finished but no vents. Wanted to tap 2-3 vents into the existing ductwork but concerned may affect system ability to heat the house. Worried if I have an HVAC company look they’ll see it as an opportunity to force sell me a bigger unit I don’t need.
Thank you so much! I was getting ready to open up that end where you just told me not to to add another piece of duct myself. Lol unfortunately what we used to have was the metal ductwork and after we had a flood in my area when the guy redid the furnace we ended up with that cheaper looking flexible stuff. I don't know if it's as good as the metal or they're about the same.
Is the solution for a spider duct system to run less lines with more branches? Mine has 4 flex ducts in one box 2x2. Two go to either end of our bonus room and two run to the upstairs bath and bedroom. The furthest runs are 20 and 25 feet. I can barely feel any airflow even by adjusting the other vents to semi closed. Thought about installing fans to push the air but am looking for a better way. No leaks or pinches in the lines.
We are replacing the 31 year old spider ductwork in our attic this week and our the HVAC contractor is planning on using mastic tape vs non-hardening mastic sealant on all the joints. Should I insist on the messier non-hardening sealant? Is it a good idea to use the non-hardening sealant layered over top of the mastic tape?
Own a ranch, have 6 ducts on the main floor 2 have high flow 2 have adequate supply and the last two are useless. Have 4 in tbe basement that are so-so. To me it takes too long to cool the house given its a 42x25 ranch. This cooling season will be the compressors third. Not only does the usless one's on the main floor not cool the two rooms they feed it's the same outcome during heating season. Have a Goodman gas furnance it is six years old. Also the duct work is original to the home (built in 1952 ). Any advice ?
Had a new hvac installed with duct work. One of the flex duct is resting on the water heaters vent pipe. Is this okay or should i put on a heat shield?
Call the contractor NOW and send a picture to them. While you wait on them to repair…. Use plastic plumbing strapping to lift and isolate the hvac duct from the heater’s vent.
I live in a mobile home. My problem is critters getting underneath and tearing into the duct work. The obvious, of course is to seal the perimeter, so critters can’t get in. That is not an option. Is there a protective covering available to put on the duct, so the critters can’t tear it up? I’m getting new ducts next week and really don’t want to start repairing within a month. Any suggestions, other than the obvious I already mentioned? Thank you!
Question: we have a central air unit that runs ac and heat through our floor vents (manufactured home) and the ceiling vents are non functional. Is it possible to use both? Cool air from the ceiling and hot from the floor?
A radial system with home runs can be balanced with balancing dampers. It would help if you weren't assuming ducts without dampers can be balanced by picking a specific-sized duct.
I'm in a newlybuilt 1500 sq. ft. townhome 2 floors 3 bedrooms, and the back 2 bedrooms never seem to get cool. I have a Carrier 14 Seer 2 Ton condenser. The air in the front bedroom and downstairs is cold enough but in the back 2 bedrooms its very warm i.e. Front room 73 Back 2 bedrooms 78. Thermostat is set for 72 but on a really hot day it runs all day trying to get to 72 but never does. Any ideas?
I bought a house in 2022 with heating/air that hadn't been upgraded since 1996. The ducts had mold in them. So we got a small company to replace all ductwork and system. The unit was in the crawlspace and had sheetmetal (with fiberglass insulation on inside) ductwork trunk line throughout the crawlspace with flexducts running off the metal trunk ductwork. I was kinda surprised when I saw after job was done that they didn't use any sheetmetal ductwork at all to replace the trunk line... only used flex duct for the entire duct system. Is that normal these days? Anything wrong with having all flex ducts?
An inline booster be added to a cold air return I don't have a basement and utility room is only so big so it would be hard to add a bigger return so I was thinking maybe I could put on inline fans and have them continuously blow and it might help feed the furnace more air thank you for all of your videos and your time creating them have a wonderful day
I’m in the process if redesigning my attic hvac system, i Have a 14” supply line off a 3.5 ton unit, two bedrooms on north end if home sit right underneath furnace in attic so they’re super short duct runs and as a result cool down and heat up super fast in comparison to other two rooms, other two rooms sit on opposite side if home, supplied from a 16x16x36 supply dist box, fed from a 30 foot 14” supply flexible duct, so you can imagine way less pressure on those two rooms, my plan is to shorten the main 14” supply duct so that distribution box sits right in the middle of the house, then feed all 4 rooms with equally distant same diameter duct line, I’m thinking that should equalize air output into all rooms, what do you guys think? Thanks
Thank you for your video good stuff and thank you for being so helpful. I have a question though that was not covered. My question is I have a 5-ton Lennox package system that is installed on my roof in Southern California in the Inland Empire which is extremely hot in the summer and gets really cold in the winter. The unit has exposed ductwork that goes from the air conditioning heating unit to inside the house and I was wondering if I should coat the exposed metal ductwork on the roof or am I just overthinking this and if you think I should put a reflective coating on the ductwork what coating do you suggest. Thank you and hope to hear from you soon
Great information that I can use when filtering out the bad contractors from the good. I only have one concern regarding this video and your better judgement; For someone who deals with leaks and mold issues in your daily profession, why do you still have carpet in your bathroom? Cheers!
Can a return be placed right next to a duct. My hottest rooms they are next to each other and it just doesn’t make sense. It’s ice cold everywhere else and super hot in my guest rooms
If a return is too close to a supply duct you basically won’t heat or cool the space effectively. The supply need to be further so the air can circulate better
@@VictorCruz-wn8tz If a return is too close to a supply duct you basically won’t heat or cool the space effectively. The supply need to be further so the air can circulate better
Just stumbled upon this after being quoted $48K for a new hvac & ductwork. Let the info gathering process begin. Perhaps there was some post hurricane (helne / milton) price gouging on, but I'm prepared to sweat it out.
hello got a concept i wonder might help. testing it right now. secondary heat exchanger went out. i dont have money to fix or replace it - echanger or furnace. blower motor and ac still work. set the fan to run constantly. placed a space heater in ta section of the return air duct to warm it . what are the cons of this working?
Please Help..my problem is I have 2 seperate Central Air Systems for my 2 family home..been getting estimates for 2 new Systems..my problem is they say can use existing duckwork also the condensors one in attic ..one in basement..I have had 4 HVAC reputable contractors give me free estimate..today just got first quote..32,500..thats alot the pdf I received only had possible one rebate from ma save for 7,500..the contractor said ..I may not qualify for more rebates..due to my home is heated by pellet stoves ..mostly not oil heat..as I have oil burner..but cant show receipts for oil purchased..as I mainly heat with pellot stoves..still waiting on 4 more quotes..Crazy..as a home owner for 47 years..running into astronomical quote..so far..still have 4 more quotes to come..I have done my Research with the BBB= Better Business Bureau..to make sure no complaints on them or that . IM NOT GETTING SCAMMED..I just hope they are being Truthful on my home not needing new du twork or new vents..Wish Me Luck..
Not sure if you are still checking messages or not but I have a kitchen in which the builder dropped 18" from the ceiling a wrap around enclosure. They did this so they would install those crappy flourescent bulbs and then cover it with a drop in plastic cover. I hope this makes sense. There is a small vent set into that dropped down enclosure. I want to tear all of that out back to the 8' ceiling, remount that vent 18" up and then close up the ceiling and repair. Should that duct move freely to bring it up and reset it or will i need to add duct work to it? What would i need to watch for? either eliminate that vent or is the duct work easy enough to move around to reposition?
Do ones it matter where you install the return air filter - whether at the back of the return air duct close to the furnace or at the front of it about 18 inches from the furnace?
I hope someone can answer my question. It feels like fiber is coming from the ducts and burning my skin and covers my bed. What do I need to do? HVAC workers keep saying says the system looks good but my skin says differently. Do you think is a leak somewhere? Can’t find help. I had check ups and was told it’s something in my house. Yes, a camera was used.
😣PLEASE HELP!!! Is it possible to switch or change ducts from insulated tube style to the rectangle style? We have a new build, but the manufacturer put in insulated tube style, and I wanted the aluminum rectangle style. It is a double wide 28' x 80', and the tubing wasn't built correctly in some areas where they wouldn't line up plume and be off by 2 inches give or take. Now I smell mice, and it stinks yo the point where we don't want to utilize our heat and/or central air!
my intake in the kitchen used to suck out down to the basement and someone tampered and now my intake is blowing air into the kitchen instead of the cellar. Is the harmful Please help.
I think they run way to much flex duct here in Arizona, in KC where I’m from it’s all metal duct, should be like commercial with no more than 6 ft of flex duct
The cooler the return air is the better your Delta T will be, correct? If your getting 80 on the return and 60 after the evap thats fine, but as the house continues to cool you should be able to maintain the 20 degree delta, correct? Lets say your return air is 75 and the temp after the evap is 55? Is my logic correct? Lets say your home temp starts off at 85 so your return temp before the evap is 87. As the home cools, your return temps go down, technically the temps post evap should.continue to go down?
Available Static pressure reduces with each reducer. In fact you get static regain if you don’t install a reducer as the velocity pressure reduces and the total pressure is fairly constant, there fore static pressure increases. Some low velocity systems I’ve designed end up being self balancing as the supply diffuser becomes the dominant resistance in the supply system which means you don’t need a balancing damper and risk of noise regeneration.
One room's warm because not much air is coming thru the vent . I played with dampener both ways but made no difference . That means duct is open / damaged or unconnected to the trunk ? That's pretty much the only thing it couild be ?
You started to talk about the end of the duct run that is capped and said you shouldn't connect any branches close to it. I understand your analogy on the holes in the straw but I'm not really sure how it relates to the branches being too close to the end.
If you put branch lines at the end of a trunkline, they will not have enough static and more airflow will go through them reducing the airflow through the others
My apartment has a fresh air vent. It's just a 10x10 return register with a duct that leads outside. It has a filter what direction should the airflow arrow point? Into the apartment or towards the ceiling? They had it facing the ceiling shouldn't it be filtering the air coming into the apartment?
In locations with cold winters I look for supply vents positioned at each window, and returns across the room from that vent. I have seen new homes with the vents and returns along the same wall and nowhere close to the windows.
Thats how florida is ( is not that its wrong) You walk thru any bedroom door typically the return is above the door and to the middle of the window (oppsite from the window) youll have the supply Everything changes once you step into georgia and the carolinas since those states get snow and then they have crawl spaces too florida homes dont(unless its from 1890 or 1900s)
System size, location and cfm determines if a trunk line should be reduced. A 2 ton in the center of a house with a even 400 cfm going each way with 10x8 metal duct wouldn’t reduce. I have done 2 1/2 ton in the center with 10x10 each way and not reduce.
@@NewHVACGuide I’m going through the same issue, I have a new unit that is appropriate to my House size, my room is not getting enough air, the one vent blows out cold, I think I need another vent, the room is about 16x16.
Great video! I'm renovating a 100 year old Detroit 3 layer brick home. One contractor told me he needs to make a hole through the bricks in order for the duct work to go through the third floor. Another contractor recommended installing two furnaces so he doesn't ruin the structure of the home. I would love your advice on this.
So far I’ve gotten 3 estimates to have A/C installed to replace the furnace only I currently have. Not once have the company looked at any of the registers, duck work or the return. 3 company’s that I’m not hiring. Should I have any confidence in the 4th will be any different?
@@johnwhite2576 yup no different… 4th said we don’t install or work on ducting, just what’s needed to adapt new unit to existing ducting. Minimum effort at a premium price… slowly putting themselves out work pushing more and more to the self install setups that are rapidly growing
I live in a duplex and I have upper two floors of house which has a supply vent in each room but no returns on either upper flooor and it’s so hot and humid up here 3 hvac companies say nothing can be done are they serious
3:57 basically my problem. I probably need a trunk that's atleast 10 ft longer so I can run shorter lines. Now I just gotta figure out the other side of the house so I can count up the cost somebody has caused me by building this house. Well hopefully those VA checks get a little bigger.
I have installed ductwork for 32 years here in Northern California. This guy did a nice job of explaining things correctly. To answer some problems- if you are getting too much air in 1 room and not enough in another room you could add balancing dampers in the ductwork to divert the air into other rooms. Also a big thing he talked about is too small return air to the unit, this causes many problems. 1 is the unit may freeze in a/c mode in summer because the unit is starved of air over the coils. He brought up static pressure. This is an issue with how the system deliveres air evenly. Proper sizing of ductwork helps delivery of air through out the home. Stepping down in size the further you go down the line is key to proper airflow. Hope this helps some of you. This guy is spot on here. Good job
Thanks pal
Paul , I have this issue on my new home , CFMs were tested in each room and it’s higher on one area and lower in another but still above the CFM plan
However, one room is hotter in summer and colder in winter
I asked for the engineering plans to be relooked at and ensure loads and cfm requirements are calculated correctly… we’ll see what they say
Also, the HVAC Tech said there are no dampeners at all , he said I’ll have to work with the registers
@Victor Cruz installing damper collars is easily done by a pro. Using the registers only makes it noisier in the room. The extra heatload in some room's could be from what's in the room generating heat. Can lights, tv, computers... Lack of window coverings on the sunny side of the house... All easily fixable.
@@VictorCruz-wn8tz Good luck with that. Unfortunately systems are rarely installed prior to closing up walls. It would be nice to be able to run those flow numbers prior provided that ALL condicalculations. (Insulation, window effcy, sun, etc) are set forth in the load calc.
👍 as a former Licensed Sheetmetal worker , estimator, business owner, and heating design, this man explains it well without going into excessive detail.
A few of years ago I got a new AC. It was supposed to be a 4 ton unit for 2200 sf. Another company came out for a free yearly checkup and I was informed I had a 5 ton unit and my ducts were not adequate. He also suggested a second return air. I had 4 estimates from 4 companies who all pretty much said the same thing. I had the first company do the job. 9k for all new ducts and additional return air. What a difference. It’s very quiet now and the whole house stays cool. Before, the living room for example would not cool down during the day with company over. That ductwork costs more then the AC install. But, I should only have to do it once!
Having enough return is an extremely important part of a properly running air conditioner. Also not using restrictive 1 inch pleated filters they cut airflow substantially.
Perfect explanation of HVAC. I’m a plumber of 30 plus years so I’ve seen some duct work. If new homeowners and about 95% of home inspectors would watch this video a lot of new homes would be left sitting! Several years ago my Dad hired in the side a couple of my sisters X buddy’s to install a new furnace and a/c unit which he purchased and of coarse he upped the tonnage which he thought would be better. Well after the install the unit which was a Lennox began having problems. Well of course he had a HVAC contractor come out and they said they couldn’t find any problems. I went and just put my eyes on it and began doing some test just using a thermometer and common sense. After doing some thinking and calling my buddy which is a HVAC company owner and explaining the situation and giving my thought on the problem he told me your exactly right. The unit was starving for return air with the unit being upsized. So I called my dad and told him I’d be over the following weekend and we can address the problem. Thank god I got there when I did because he had already drew out lines on the walls where he wanted the return vents and had started cutting Sheetrock with a razor knife. I stopped him in his tracks from cutting any further and told him we’re not going up into any walls we’re gonna go through the floor! Short story long we finally got the returns in and the unit has worked fine ever since! The contractor world needs more Professional People like you in it!!!
I thought returns are always through walls near the ceiling and not the floor ?
I have a 1200sqft 3/2 and a 2.5 ton unit that is 3 years old. The air handler is in the attic, and I'm replacing the entire duct system from the 70's by myself. Your video has been the most helpful I have found yet. You even used the same size house/HVAC unit I have as your example. Praise The Lord, Jesus Christ.
As a retired engineer (BSEE) I have to say that the duct work IS the weakest link, and although the airflow dynamics can become quit complex Mr. Griffin provided an excellent, easily to understand explanation. Einstein quote: “If you can't explain it simply, you don't understand it well enough.” This is who I would want to do all my duct work service.
Always check behind your plenum box and make sure they sealed the area off from the attic if you have a closet mounted blower! Paid $8k and found the installer never sealed the back 4” off so I was pulling dust , dirt, and gross outside air into the closet into the intake and through and out the duct work! I fixed it myself because I’m so sick of being scammed by AC guys.
same here. my guy showed up smelling like weed and the plenum wasn't even square to the point of having a 1/2 inch gap on one side which he "mastic'd up". I had my drywall contractor come behind him and seal between the plenum and the attic. He also created a flow unbalance and one of my bedrooms gets hardly any flow.
Well you just disappointed about 75% of home owners. Unfortunately builders and many home owners use cheap mechanical contractors for residential the majority of time. Therefore you get low skill labor at a a good price. Get multiple estimates from reputable companies and ask to see their work. If they can’t show you photos they don’t take pride in what they do. Doesn’t matter if you spent 20k on your new system if it isn’t installed correctly. Do your research on companies. Ask to see their work. If it doesn’t look good, it’s probably not. People that do good work take pride in their craft. It should look clean, not like a rats nest, or bomb went off. It should be sealed. Trash shouldn’t be left in the attic or basement etc. quality mechanical contractors are definitely out there but it’s up to the home owner to do their research on the companies they hire.
Thank you. You earned my support. I’m pretty sure you solved my house heating issue. I probably have a 30 foot trunk with a 90 degree angle all the same diameter. The two rooms in the end are freezing.
Thanks for arming us with information. We are also grateful for all of the helpful comments of your viewers.
Thank you for this video! Wow, my home has all of those issues…trunk not stepped down, rooms warmer than others, same size (6”) duct going to every room regardless of size, supply coming off the end of a trunk.
I’ll be calling for someone to review it this month!!
The biggest issue for indoor air quality and occupant health is actually duct leakage. Even brand new duct systems leak quite a bit. Our brand new, pretty well done duct system actually had 120 cfm of total leakage. We had aeroseal seal it all up for us. Everyone is breathing contaminated air, pressurizing, or depressurizing their home with poorly sealed duct work. No good. Contractors building building's envelopes and mechanical systems are directly affecting the health of the occupants. In my new house, I needed to add ventilation because VOC's were too high making me not sleep well and our house prior to sealing the ducts was pulling in attic air and pressurizing the house. There's a lot of data now showing indoor air causes lots of chronic health problems. It's time for A/C guys to start paying attention instead of just throwing in a single speed A/C with a fiberglass filter, no ventilation, no dedicated dehumidification for mild months, and etc. Into homes and not thinking anything of it.
When we come to your home and tell the homeowner what needs to be done on a new home install or changing out the equipment in a older home,it all comes down to what they can afford.
As far as duct work it’s code to seal all the joints but sadly not the designing of the system.its a lot of hacks out there.we can sell you high seer inverter systems with high in air purifiers,ultra violent lights,humidifiers,ERV systems but the majority of people can’t afford this level of job.
Then the homeowner needs to pay for it. Builder only pays for bare minimum. You want it? You pay for it.
In California the system has a duct test. The test goes right to Sacramento, this is done by an independent company. So, little to no leakage.
Yeah like on mobile homes. The plumbers, electricianz, and AC guys drill holes in the sub floor and dont seal. So literally a bunch of seals not sealed let alone ducts are never installed correctly.. you need the right tapes, spray glues for the tape.etc. just did our home and we had a basketball sized hole in the trunkline where a duct used to be.. they had it capped but it was just tape and over time just fell to the floor... Lol
I rented a 5000sq ft building for my restaurant, was having trouble with the air flow. I was shocked when i went in the attic and see what the previous rented had done. 2 4 ton units main duct work was about 8 foot long, each unit had 12 vents. but they used 12 flex to all the vents and tapered down to 6'' about 3 foot before the vent. this caused NO AIR FLOW. not to mention the power bill was 1200 a month. i fixed all the ducts. and air flow is good and power bill is down to 550.
I’ve got an addition I’m running duct to and I’ve gotta run 4 more vents. About 30ft away for all of them. Might scrap that idea and do a mini split for it
You can put dampers on the “spider” systems and balance out the air flow in each room.
This is such a critical video. I think I'm going tour some new open houses in my area and see if the ductwork is up to par like the points you made in this video, and then find out who the HVAC installer is for those properties!
Let me know how that goes pal. Good or bad
@@NewHVACGuide Will do! Just the fact the you're protecting people's investments is awesome because nothing more I hate is spending hard earned money only to be disappointed afterwards.
@@NewHVACGuide You should do a video on return duct strategy & placement. I went round & round with the scabs that installed my mothers system back in 76 about return ducts. They should have louvered vents with 1 high and 1 low on each floor so that in winter they suck cold air into the furnace and in summer they suck hot air into the A/C system so the system can adjust the house air pocket to make the T-Stat work less often to maintain a constant temp and make the system cheaper to use. They put the only return duct in the downstairs floor and in summer the upstairs temp was 45* hotter than downstairs. 25 yrs later I got the house and cut the wall open and added a return upstairs and evened out the temps myself.
You bring up a good point. Makes me wonder if sometimes things are not done properly because they are trying to keep the cost down as much as possible or if some folks are just simply lazy?
@@NewHVACGuide the answer is both unfortunately
The answer is both
Just finished installing a 12 ton commercial unit I got off of eBay in my 1200 sq ft bungalow here in northern Minnesota. Haven’t turned it on yet. My good friend told me that 1 ton per hundred square feet of living space is a good rule of thumb to use for sizing estimates. Is this correct?
usually you can adjust the air flow by closing or opening vents in the room. i have 31 apartments and homes. that always done it for me.
2:10 Those step downs aren't for the rooms at the end of the trunk line, they are for the branches BEFORE the step down. If the trunk doesn't reduce in size all the air will pass freely to the last vent.
No. Path of least resistance
Hi
3 ton YORK gas furnace would be able push air in 65ft proper sized duct work?
Many thanks!
This explains my attic system servicing my 2nd floor. The largest bedroom has two ducts and good performance. Those ducts are at the end of the plenum. Bath/hallway/smaller bedroom also OK in that they are balanced temps.
But there is a 3rd bedroom end of hallway often too hot or too cold. It has the longest duct run. And unlike the other bedrooms, two walls face outside and lack of insulation is an issue (house is over 80 yrs old). I'm considering adding a 2nd duct run to that room.
Good video.
I have 6 inch lines for rooms.
My question is return air will be 6 inch as well.
Can I install 4 " vent for washrooms? Approximately 50 sft.
thank you, sharing your knowledge... U explained simply (& Logically) ..Am "simple home owner" (not in industry) w/ desire to know: "should expect of duct work": design & function
Plenums with duct work off the sides work good as long as you keep your take offs towards the cap and use volume dampers at wys for each supply to vent. And alway as Mr Griffin said step down size at transitions Great video 👍🏽
I have a very centrally located electric furnace. Can I come out of the plenum on all sides like a Medusa? I don’t have a particular direction I need a trunk.
My back rooms do not get warm enough. My hvac is up in the attic. What kind of company does duct work inspection and repair?
If one of room has too much air flow and noise, should I add a damper which close half of airflow?
My Ductwork in my 2nd floor blows massive velocity cold air in the open area & hardly any velocity in the three bedrooms.
There are air vents are over my downstairs & it freezes us downstairs.
Whereas the bedrooms are 6 to 10 degrees hotter.
Can the bigger ducts go to the bedrooms instead?
I have a 25 year old home. My master bedroom doesn’t get enough heat. It’s super cold. I cleaned the vents already. Idk what I can do about it. Pls suggest
10 years ago I had round hard ductwork installed and it’s cooled the house better than ever. Recently I called a company to check for a leak in my unit and they ended up sending out a couple guys to give me a estimate on a new system. We had heavy rain the previous day and they told me they couldn’t price a new unit without new ductwork as it got wet and had water inside.
The ductwork was installed with hangers and may appear it’s laying on the moisture barrier but it may just be the insulation that got wet. I don’t see how they can tell if water is inside. It’s a large heavy duct . They left without giving me a quote because I declined new ductwork. What do you think?
I have a finished basement and we put in a new air and heat pulling cut out and made. Can't see why heat isn't coming out like before.
I have a Mobil home ac vents are in the floor. ? Is should the return air be up high over the coil or should it be in front of the coil I ask this because when I got the trailer it has two returns 16/20/1 direct above the coil. It’s a 4 ton
I had a mehane leak. They put silver tape around and suggested a bird's nest may be in the pipe exiting at the top of my roof . I cannot see any damage to this small pipe from the ground but I am nervous . They sealed off the leak but I am elderly and not able to climb on my short roof .Can I call the fire dept. for advice ? I spent all my $$.on getting the motor cleaned which is what HVAC recommended. I didn't have any issues , no whistles, no shutoffs at the thermostats or alarms . Any suggestions ?
I have the HVAC system in the attic in a new 2 story house. I have a duct that is not routed to any room, it’s just blowing cold air into the attic. Is that normal or the contractors just left it incomplete?
Incomplete!
Wasting energy
Thanks for the video. I have a question I hope you can answer. We did a remodel on our kitchen. There was a Half wall that created a small entry space from the front door that we had removed to enlarge our kitchen.
This wall had a hot air duct that pointed into the small entry way. After the renovation and removal of the wall, that same vent now is open and points down into our basement area. Can I remove that since there is already a vent into that room or should I leave it alone? thanks
When installing an exhaust vent for a stove, it it required for the vent to be double walled to keep surrounding building materials from getting hot?
Should the large pipe leaving the AC Handler that is covered in the BLACK INSULATION be sweating? It that normal?
I’m a hvac apprentice and I’ve been doing new construction duct work install for the past few months. Can I make a career out of duct work or is it just a good start?
If you have flex ducting can you installed a and if not do they make something to where you can just take the duct off of the supply and just cap it or something
My house is built on a slab. There's a crawl space/attic. However, the ductwork is in the ceiling and walls. How do I find out what ductwork I have? I don't know if it's suitable for a 2 or 3-ton system.
My ac broke last summer. Now I need to replace both AC and my ancient furnance. Only to find out the duct work is too small for the house I have and no matter how good my systems are, it will struggle to cool the 2nd floor.
Most contractors I talked to won’t give me any technical details in size of the unit needed, what size ducts are needed for my home.
I had my basement finished in 2003. I had it stated in the contract no duct tape. When I saw the hvac person using duct tape I told him to stop.
He argued with me saying it doesn’t matter if the ducts leak, the heat is still going into the house. I told the general contractor to find a different hvac person.
Too bad I didn’t know about mastic at the time. I should have specified that. But at least all the new joints have foil tape.
I have a 5 legged spider to deal with. Definitely looks like a DIY project by previous owner. Big, fat 9 inch ducts with asbestos tape. No HVAC company will touch it so I gotta do it myself. I'm hoping to find some sort of cap for the extra holes and commit to a main trunk line off of the remaining take off. Then will use flex duct to reclaim some ceiling space.
Would you have air ventilating trough your ducts with the fan on your residential unit off.
Best explanation I have ever heard. Thank you so much!
I have a 3500 sq ft house, two floors. The furnace heat comes out only from the left side of the house. I checked the duct work, both sides of the house come out from the same duct, I am confused.
Is there way to determine if your existing HVAC system is big enough to add room vents to? I have a basement that was finished but no vents. Wanted to tap 2-3 vents into the existing ductwork but concerned may affect system ability to heat the house. Worried if I have an HVAC company look they’ll see it as an opportunity to force sell me a bigger unit I don’t need.
As a duct man and owner of a small factory for duct works i do all your three points
Thank you so much! I was getting ready to open up that end where you just told me not to to add another piece of duct myself. Lol unfortunately what we used to have was the metal ductwork and after we had a flood in my area when the guy redid the furnace we ended up with that cheaper looking flexible stuff. I don't know if it's as good as the metal or they're about the same.
Is the solution for a spider duct system to run less lines with more branches? Mine has 4 flex ducts in one box 2x2. Two go to either end of our bonus room and two run to the upstairs bath and bedroom. The furthest runs are 20 and 25 feet. I can barely feel any airflow even by adjusting the other vents to semi closed. Thought about installing fans to push the air but am looking for a better way. No leaks or pinches in the lines.
We are replacing the 31 year old spider ductwork in our attic this week and our the HVAC contractor is planning on using mastic tape vs non-hardening mastic sealant on all the joints. Should I insist on the messier non-hardening sealant? Is it a good idea to use the non-hardening sealant layered over top of the mastic tape?
Own a ranch, have 6 ducts on the main floor 2 have high flow 2 have adequate supply and the last two are useless. Have 4 in tbe basement that are so-so. To me it takes too long to cool the house given its a 42x25 ranch. This cooling season will be the compressors third. Not only does the usless one's on the main floor not cool the two rooms they feed it's the same outcome during heating season. Have a Goodman gas furnance it is six years old. Also the duct work is original to the home (built in 1952 ). Any advice ?
goodman-my condolences...
Had a new hvac installed with duct work. One of the flex duct is resting on the water heaters vent pipe. Is this okay or should i put on a heat shield?
Call the contractor NOW and send a picture to them. While you wait on them to repair…. Use plastic plumbing strapping to lift and isolate the hvac duct from the heater’s vent.
Do you have a video on cleaning your air duct work?
I live in a mobile home. My problem is critters getting underneath and tearing into the duct work. The obvious, of course is to seal the perimeter, so critters can’t get in. That is not an option.
Is there a protective covering available to put on the duct, so the critters can’t tear it up? I’m getting new ducts next week and really don’t want to start repairing within a month. Any suggestions, other than the obvious I already mentioned? Thank you!
They have the spray foam for ductwork now. I’m not sure that’s a perfect solution but maybe it might inhibit the critters?
them rats hate tin foil...
Question: we have a central air unit that runs ac and heat through our floor vents (manufactured home) and the ceiling vents are non functional. Is it possible to use both? Cool air from the ceiling and hot from the floor?
A radial system with home runs can be balanced with balancing dampers. It would help if you weren't assuming ducts without dampers can be balanced by picking a specific-sized duct.
Can move from walls to ceiling? Trying to move duct in kitchen
Wonder if R value in duct work fits into the equation? R-3 flex doesn't cut it with my home in Texas.
I'm in a newlybuilt 1500 sq. ft. townhome 2 floors 3 bedrooms, and the back 2 bedrooms never seem to get cool. I have a Carrier 14 Seer 2 Ton condenser. The air in the front bedroom and downstairs is cold enough but in the back 2 bedrooms its very warm i.e. Front room 73 Back 2 bedrooms 78. Thermostat is set for 72 but on a really hot day it runs all day trying to get to 72 but never does. Any ideas?
I bought a house in 2022 with heating/air that hadn't been upgraded since 1996. The ducts had mold in them. So we got a small company to replace all ductwork and system. The unit was in the crawlspace and had sheetmetal (with fiberglass insulation on inside) ductwork trunk line throughout the crawlspace with flexducts running off the metal trunk ductwork. I was kinda surprised when I saw after job was done that they didn't use any sheetmetal ductwork at all to replace the trunk line... only used flex duct for the entire duct system.
Is that normal these days? Anything wrong with having all flex ducts?
How can I tell what my supply side is?
An inline booster be added to a cold air return I don't have a basement and utility room is only so big so it would be hard to add a bigger return so I was thinking maybe I could put on inline fans and have them continuously blow and it might help feed the furnace more air thank you for all of your videos and your time creating them have a wonderful day
I’m in the process if redesigning my attic hvac system, i Have a 14” supply line off a 3.5 ton unit, two bedrooms on north end if home sit right underneath furnace in attic so they’re super short duct runs and as a result cool down and heat up super fast in comparison to other two rooms, other two rooms sit on opposite side if home, supplied from a 16x16x36 supply dist box, fed from a 30 foot 14” supply flexible duct, so you can imagine way less pressure on those two rooms, my plan is to shorten the main 14” supply duct so that distribution box sits right in the middle of the house, then feed all 4 rooms with equally distant same diameter duct line, I’m thinking that should equalize air output into all rooms, what do you guys think? Thanks
Any idea why my HVAC starts smelling bad when the fan is runnint 24/7 vs intermittently? Smells musty almost.
Thank you for your video good stuff and thank you for being so helpful. I have a question though that was not covered. My question is I have a 5-ton Lennox package system that is installed on my roof in Southern California in the Inland Empire which is extremely hot in the summer and gets really cold in the winter. The unit has exposed ductwork that goes from the air conditioning heating unit to inside the house and I was wondering if I should coat the exposed metal ductwork on the roof or am I just overthinking this and if you think I should put a reflective coating on the ductwork what coating do you suggest. Thank you and hope to hear from you soon
Great explanations man. I'm definitely subscribing.
How do I stop cold air coming from the attic return when the heat is off?
Have you tried turning on the air circulate on the thermostat? Also seal around the Plenum/registers.
@@NewHVACGuide Just tried that and when its on there is no cold air.
Great information that I can use when filtering out the bad contractors from the good. I only have one concern regarding this video and your better judgement; For someone who deals with leaks and mold issues in your daily profession, why do you still have carpet in your bathroom? Cheers!
Can a return be placed right next to a duct. My hottest rooms they are next to each other and it just doesn’t make sense. It’s ice cold everywhere else and super hot in my guest rooms
I have a similar situation
Lmk what you find!
If a return is too close to a supply duct you basically won’t heat or cool the space effectively. The supply need to be further so the air can circulate better
@@VictorCruz-wn8tz If a return is too close to a supply duct you basically won’t heat or cool the space effectively. The supply need to be further so the air can circulate better
Just stumbled upon this after being quoted $48K for a new hvac & ductwork. Let the info gathering process begin. Perhaps there was some post hurricane (helne / milton) price gouging on, but I'm prepared to sweat it out.
hello got a concept i wonder might help. testing it right now. secondary heat exchanger went out. i dont have money to fix or replace it - echanger or furnace. blower motor and ac still work. set the fan to run constantly. placed a space heater in ta section of the return air duct to warm it . what are the cons of this working?
Please Help..my problem is I have 2 seperate Central Air Systems for my 2 family home..been getting estimates for 2 new Systems..my problem is they say can use existing duckwork also the condensors one in attic ..one in basement..I have had 4 HVAC reputable contractors give me free estimate..today just got first quote..32,500..thats alot the pdf I received only had possible one rebate from ma save for 7,500..the contractor said ..I may not qualify for more rebates..due to my home is heated by pellet stoves ..mostly not oil heat..as I have oil burner..but cant show receipts for oil purchased..as I mainly heat with pellot stoves..still waiting on 4 more quotes..Crazy..as a home owner for 47 years..running into astronomical quote..so far..still have 4 more quotes to come..I have done my Research with the BBB= Better Business Bureau..to make sure no complaints on them or that . IM NOT GETTING SCAMMED..I just hope they are being Truthful on my home not needing new du twork or new vents..Wish Me Luck..
Not sure if you are still checking messages or not but I have a kitchen in which the builder dropped 18" from the ceiling a wrap around enclosure. They did this so they would install those crappy flourescent bulbs and then cover it with a drop in plastic cover. I hope this makes sense. There is a small vent set into that dropped down enclosure. I want to tear all of that out back to the 8' ceiling, remount that vent 18" up and then close up the ceiling and repair. Should that duct move freely to bring it up and reset it or will i need to add duct work to it? What would i need to watch for? either eliminate that vent or is the duct work easy enough to move around to reposition?
Bro you have explained exactly what I was looking for YOU'RE VIDEO WAS AMAZING, THANK YOU, best explanation 👏 🙌 👌 everrrr!!!
Wow. Thanks pal
@@NewHVACGuide you're welcome have no idea how much that helps now I can put the peices together
Do ones it matter where you install the return air filter - whether at the back of the return air duct close to the furnace or at the front of it about 18 inches from the furnace?
I hope someone can answer my question. It feels like fiber is coming from the ducts and burning my skin and covers my bed. What do I need to do? HVAC workers keep saying says the system looks good but my skin says differently. Do you think is a leak somewhere? Can’t find help. I had check ups and was told it’s something in my house. Yes, a camera was used.
Has anyone ran a camera?
Yes
😣PLEASE HELP!!!
Is it possible to switch or change ducts from insulated tube style to the rectangle style?
We have a new build, but the manufacturer put in insulated tube style, and I wanted the aluminum rectangle style. It is a double wide 28' x 80', and the tubing wasn't built correctly in some areas where they wouldn't line up plume and be off by 2 inches give or take. Now I smell mice, and it stinks yo the point where we don't want to utilize our heat and/or central air!
Yes it’s possible
my intake in the kitchen used to suck out down to the basement and someone tampered and now my intake is blowing air into the kitchen instead of the cellar. Is the harmful Please help.
I think they run way to much flex duct here in Arizona, in KC where I’m from it’s all metal duct, should be like commercial with no more than 6 ft of flex duct
Yeah here in Topeka city inspectors came to a new apartment building and they ran all flex duct and made them take it all out lol
The cooler the return air is the better your Delta T will be, correct? If your getting 80 on the return and 60 after the evap thats fine, but as the house continues to cool you should be able to maintain the 20 degree delta, correct? Lets say your return air is 75 and the temp after the evap is 55? Is my logic correct?
Lets say your home temp starts off at 85 so your return temp before the evap is 87. As the home cools, your return temps go down, technically the temps post evap should.continue to go down?
Available Static pressure reduces with each reducer. In fact you get static regain if you don’t install a reducer as the velocity pressure reduces and the total pressure is fairly constant, there fore static pressure increases. Some low velocity systems I’ve designed end up being self balancing as the supply diffuser becomes the dominant resistance in the supply system which means you don’t need a balancing damper and risk of noise regeneration.
How about dempers ? Do you need to install to have regulate ?
Most residential home... properly sized and installed ductwork should not need to be balanced by dampers typically.
Thank you. This helps a lot. I see my house has this straw issue in the attic.
Very common pal.
I made 2 million dollars this year!!!😁 but this video is amazing 💪🏾💯💯
One room's warm because not much air is coming thru the vent . I played with dampener both ways but made no difference . That means duct is open / damaged or unconnected to the trunk ? That's pretty much the only thing it couild be ?
Sounds like it could be 🙂
Imma go in my basement and check this out. Mad issues unattended for a couple winter seasons now. Landlords grrrr.
You started to talk about the end of the duct run that is capped and said you shouldn't connect any branches close to it. I understand your analogy on the holes in the straw but I'm not really sure how it relates to the branches being too close to the end.
If you put branch lines at the end of a trunkline, they will not have enough static and more airflow will go through them reducing the airflow through the others
@@NewHVACGuide okay I see. Is there a rule of thumb about how far away from the end cap you should put your closest branch?
@@NewHVACGuide But they do it anyway because no one want to box in heat runs and not have nice clean lines in the house
Amazing tips…makes so much sense, thanks
My apartment has a fresh air vent. It's just a 10x10 return register with a duct that leads outside. It has a filter what direction should the airflow arrow point? Into the apartment or towards the ceiling? They had it facing the ceiling shouldn't it be filtering the air coming into the apartment?
Arrow towards the unit. If your taking in fresh air from the outside.
In locations with cold winters I look for supply vents positioned at each window, and returns across the room from that vent.
I have seen new homes with the vents and returns along the same wall and nowhere close to the windows.
Thats how florida is ( is not that its wrong)
You walk thru any bedroom door typically the return is above the door and to the middle of the window (oppsite from the window) youll have the supply
Everything changes once you step into georgia and the carolinas since those states get snow and then they have crawl spaces too florida homes dont(unless its from 1890 or 1900s)
System size, location and cfm determines if a trunk line should be reduced. A 2 ton in the center of a house with a even 400 cfm going each way with 10x8 metal duct wouldn’t reduce. I have done 2 1/2 ton in the center with 10x10 each way and not reduce.
Very well explained and cleared up a lot of unanswered questions for us Beginners, thank you
You are welcome!
@@NewHVACGuide I’m going through the same issue, I have a new unit that is appropriate to my House size, my room is not getting enough air, the one vent blows out cold, I think I need another vent, the room is about 16x16.
Great video! I'm renovating a 100 year old Detroit 3 layer brick home. One contractor told me he needs to make a hole through the bricks in order for the duct work to go through the third floor. Another contractor recommended installing two furnaces so he doesn't ruin the structure of the home. I would love your advice on this.
Did it cost u alot to renovate a 100 year old house, I saw 1 that I like but I'm afraid to risk it.
@@abiolaashby7117 I'm still working on it. I would definitely budget for it. It really depends on who you hire, and what type of work the home needs.
High efficiency one got plastic exhaust way easier that the old ones
So far I’ve gotten 3 estimates to have A/C installed to replace the furnace only I currently have. Not once have the company looked at any of the registers, duck work or the return. 3 company’s that I’m not hiring. Should I have any confidence in the 4th will be any different?
Probably no different
@@johnwhite2576 yup no different… 4th said we don’t install or work on ducting, just what’s needed to adapt new unit to existing ducting.
Minimum effort at a premium price… slowly putting themselves out work pushing more and more to the self install setups that are rapidly growing
Wish you also did Alexandria, VA.
Great explanation
Thanks for watching!
I live in a duplex and I have upper two floors of house which has a supply vent in each room but no returns on either upper flooor and it’s so hot and humid up here 3 hvac companies say nothing can be done are they serious
Where's the unit located ?
3:57 basically my problem. I probably need a trunk that's atleast 10 ft longer so I can run shorter lines. Now I just gotta figure out the other side of the house so I can count up the cost somebody has caused me by building this house. Well hopefully those VA checks get a little bigger.