Great video as per usual Charlie! Thanks for the shout-out. Bit of an update on mine - bear in mind mine isn't in a domestic environment, it's in a studio. The Kair MVHR fixed my mould and damp issues, which was my primary objective. However since my studio isn't heated 90% of the time I doubt the heat recovery side is doing much and in reality it's destroyed my soundproofing 😂😭. A future project will be to fix this properly but it's not particularly urgent. Sadly that will probably involve removing the MVHR since the simultaneous 'IN & OUT' through a single hole really complicates things when it comes to making a soundproof enclosure. But it's been running on trickle for over a year with no issues and more importantly my studio is now mould-free. The BSK system looks great! 👍
Thanks for the great update Andy. Yes it's a nice bit of kit but the Kair seems to be pretty tech/ hardware heavy in comparison. Possibly more efficient on the heat recovery, or maybe the BSK is just a brilliant design? Who knows. I'll be really interested to see how you solve this whilst keeping the studio sound proof. 👊
Thanks Charlie, love your videos. I put 3 of these BSKs into our poorly insulated 1990s 3-bed semi. Definitely helped with air quality, humidity and winter window condensation (however it certainly didn’t eradicate the condensation). We have the humidity auto-boost switched on and (while it's useful) we find the beeper/sounder quite annoying when it changes back and forth between normal and boost. Especially at night. So I plugged up the sounder with a little toilet paper and glue! Worked perfectly. 😊 All the best from Ireland.
Thanks, that's great feedback. How did you set them up in terms of working together? It's very hard to eradicate condensation particularly if you've got single glazed windows. You can see the difference here ruclips.net/user/shortslQv5FIZd9Qc?feature=share - I don't think I'll ever eradicate condensation in that bay! PIVs seem to be the answer for that though
@CharlieDIYte Hi again, Charlie. To answer your question: I set up 2 units in the 2 occupied bedrooms in parallel with each other. And the 3rd unit running opposite them (in the upstairs home office). Theory was to encourage continuous air movement upstairs. In practice, I agree with some of your other viewers' comments and feel the 3 are not strong enough to push ALL the air around our leaky old house. But they definitely helped us, I enjoyed doing the work and l learned a thing or two at it. So 'jobs a goodun' as you Brits like to say. I'm smiling here at your positivity: that condensation on the window = a free dehumidifier :-). I like that! All the best.
I used BPC to design a whole house MHVR on my newbuild. The design worked perfectly, very little wastage in pipe runs. Fantastic humidity/temperature control throughout the building. No cold spots in corners of rooms with a gentle circulation of air
You made a maximally effective metal cold bridge between outer wall and inner wall with the galvanised ducting. You can see it in the IR shots from 15:18 onward.You probably should have swapped that out for the plastic one.
@@CharlieDIYte Not going to argue with you, as you have all the experience here. I just looked at the IR footage and immediately spotted the colder blue ring, compared to the surrounding wall. Maybe it is not as dramatic as it looks in real life.
I was thinking exactly the same. as soon as I saw the metal ducting. But absolutely loved the method of joining the duct to the membrane inside, genius. Oh and a perfect chain drill instead of a core drill, work of art. 👍
@@stephen-boddyI know. I was properly kicking myself for doing that. The important thing is I don't think anyone else will be making the same mistake. I'm not convinced their telescopic option is brilliant either though as you've got leakage between the pipes mid way though but as you say, better that than having a cold bridge from front to back.
A great video. We have installed MVHR as we did our massive bungalow reonovation and it has made a huge difference to the house. It was quite hard for us to do that so something like this for older properties are a great option.
Nice one Charlie, I fitted one of those (not that model, a 4" one) and it failed within 6 months. Was very close to getting one of those 6" but the reviews were pretty rare, I'll be keen to know if it lasts a fair while. Keep up the good work 👍
Love the reference to keyboard warrior people saying you should use a core drill.. - Personally, i love that you show people how to do this with stuff they actually might already have in their tool kit! I've said it before, but your videos are an inspiration and yours (along with Mr Mac's) jump to the top of my viewing list when they appear. Looking forward to the next video!
@@aesopshair6690 Thanks, will check it out.. - Actually, thats another thing i really like about Charlie's videos.. He doesnt try to make out he is something he is not. He owns up when he made a mistake, and gives full disclosure as to his involvement with a company. "they gave me this, and i get to keep it, but they dont have any editorial say" - and in the case of this video, "i bought a pipe, but didnt need to" - then makes the best of the situation, often to advantage. The internet needs more channels and RUclipsrs like Charlie.
Thanks Martin, can't tell you how much I appreciate that. Yes the mistakes are a very important part of it for me. Take them out and it's not real life 😉👊
OK, I have run the numbers. At its highest setting (60 cu m /hr) if you leave it extracting for 5mins (10 mins total, as it only extracts half the time) then if it is freezing outside and 20C inside you will have saved 18Whrs of heat. Which, with electric direct heat will cost you around 0.48p (gas or heat pump around a quarter of that). Used twice a day (but savings only in Winter), that will be a buyback of just over 100 years... So not for bathrooms then... Air change for the rest of the house? Well, you will need 2 or 3 running flat out to meet recommended minimum air change- and a hermetically sealed house. Do you run out of breathing air at the moment? If not, it is getting in somewhere, and that would need to be sealed. Night mode is a quarter the flow, so eight hours a night for say 120 freezing equivalent nights (generous) is about £1.30 worth of gas a year. Less the 26p it would cost to run it. More than 100 years then. And assuming that it needs no maintenance, like filter cleaning.
@@tommotube It looks good on the adverts... Having said that, centralized systems can do better. What I can get no-one to answer is- why are we using air to water heat pumps in this country? The rest of the world uses air to air. If you do that, you can couple your air change system to your heating system, use the same fan and add heat all in one place. Heating companies, if you have not thought of that, you can have the idea for free.
Thanks, brilliant analysis. Yes I hear what you say on the payback. Trouble is if I ran that analysis on everything I do in this old cottage I'd never do any renovations 😉 I'll never get the money back on the ufh and wall insulation but it gives us joy every time we go in there particularly in these cold months - it's typically 2 degrees warmer in there than the heating is set to and I guess you'd say it's transformed the thermal footprint of the house.
@@CharlieDIYte Sorry, I cannot help analyze such items- especially when the specification is vague and rings alarm bells. For many years I was a consulting engineer, often asked to appraise a design before it went to market. It was alarmingly common for the physics involved not to be examined. In some cases, the objective was actually impossible, and no-one had spotted it. This item is one that works, but so poorly that it is not worth its cost never mind its installation. It also has issues with dust retention and maintenance. If ventilation is needed, a simple extractor is better- spend the difference on draft proofing. The claims made are wild- the best heat recovery systems are, at best, 80% (often measured with ~24C inside and ~-5C outside) and I am deeply suspicious of the power requirements- they are around a tenth of the Kair unit... Heat recovery can work, but it requires a whole house approach designed into the build. BTW, removing that metal duct ( a serious thermal bridge) will save more heat than the unit.
@@Tensquaremetreworkshop No need to apologise. You're absolutely right - and this calls for a follow up video at some point. Yes I'm painfully aware of the issue with that duct - I've created a flawless cold bridge when I'm always at pains to tell people the danger of cold bridging. Crazy how you miss the most obvious things when you're mired in the details of a project. It'll need some thought though as that telescopic pipe they provide isn't perfect either - it needs siliconing to prevent moisture getting through the gap between the two pipes. Yes the dust filter is ridiculous, again something I should have made more of a point of. I did at least highlight the issue if not the problem of that dust being blown back in the supply phase.
As someone who lives in perpetual frigidity due to their wife opening all the windows to “let the house breathe” even in the dead of winter, I’ve never clicked “Save to Watch Later” so fast.
@@CharlieDIYte Oh she's absolutely right (I quickly learnt she almost always is). And coming from a country which takes ventilation much more seriously than we do (even their Soviet-era tower blocks have proper chunky wind-shielded window vents), she couldn't help but laugh at our piddly trickle vents. So I have both her and yourself to thank for opening my eyes to the importance of fresh air (not just to avoid damp issues but also the effects of CO2 buildup on cognition and mental health), and leading me down the rabbit hole of PIV, MVHR, etc. 🙂
Great video; very informative ! The "Tiny Off-Grid House Research" interest in decentralized ventilation is not primarily focused on just providing ventilation, or heating the incoming fresh air but more importantly the removal of moisture and humidity from the indoor air space which can facilitate the growth of microbial molds and fungi which can be harmful to the occupants respiratory health and cause structural damage to the house
True! As you can see from my calculations (main post) the heat recovery is trivial. Humidity and CO2 control is much more important. Worth buying a version that monitors that.
I fit the same unit in my garden office as the CO2 levels were quote high, I switched the filter out for HEPA, but does a good job. Dont really notice any reduction in heat/cooling in the room. Planning to do the same in a couple rooms within the house soon. Only things missing is integration with Home Assistant, and I wish the app could do full scheduling instead of just an entire day.
The filter is to protect the unit, not you! It is actually detrimental - it traps dust, spores, etc on the way out, and then blows them back into the room when it reverses. (the outside air is much cleaner than the internal air- use a particulate meter if you do not believe me.)
Looking forward to a longer term review. Also go buy another one and let us know how the paired function works. Then I just gotta find a decent electrician to put the mains wire in.
Cut into the render with a Stanley knife around the external hole to avoid tearing the render finish. Regardless of whether you’re chain drilling or using a core bit in render.
So now we just need to install two or three of these in every old house in the UK and the mould problems would be sorted. Would be good to see more people install these to get a buzz around them and so the market grows.
Hi Charlie Contentious topic , which in a way highlights the difference in how we live in the modern age . The more we do to increase the temperature in our homes the more challenges we encounter , the main difference is the change in the way we actually build and design our homes . Certainly compared to the terrace house I grew up in my youth back in the early 50s . A fire place in every room and single glacéd sash windows that leaked like sieves . And I think here we have a possible compromise that is worth considering , I now live in a well insulated double glazed detached house . Yet we also have a wood burning stove , that is only used in the coldest of weather . Yet it sits there providing a passive form of ventilation , this ability I think we have lost sight of with the passing of time . Yes the powers that be , seem determined to prevent the use of wood burners . But even if this came to pass , I would still keep ours for its ventilation properties, and have a bunch of dried flowers inside . Kind regards as always .
If you are able to run your log-burner without opening a window, that suggests you have other sources of ventilation too. There are probably dual air vents to the fireplace area.
So true. We also have a wood burner which is now almost redundant since we installed under floor heating. But you're absolutely right in well insulated double glazed houses it's critical to have some form of ventilation - trickle or otherwise. I suppose the only question is whether in the absence of trickle vents, your open wood burner is providing sufficient ventilation. Better than nothing though!!
@@CharlieDIYte Log burners leak like a sieve- unless you have a flue valve. And there has to be air ingress to allow it to work. Your heat loss from this will almost certainly. exceed that fan recovery. To save heat, a flue valve would have been a better purchase...
That was roughly the midway point between the 2 temperatures. If, when it is much colder, it can still deliver the midway point, that would be a huge saving.
A good video, thank you. Have you ever done one on the thermal imaging dongle thingy? As a seasoned pro who has drilled thousands if not millions of holes in his time you're doing it right. Core drills suck, especially in hard brick.
a supply temperature of 14.5/15 degC with 14 degC outside does not show much heat recovery really. The way to test the heat recovery capability of this device would be with some colder weather, with something like 5 or 0 degC outside, where I would expect the supply during the 7 minutes cycle to remain at least above 10deg C, possibly higher, and see how it goes down while the thermal energy stored in the ceramic mesh depletes. Also, another thing to consider is that unless you work with 2 devices meshed in "push-pull" configuration, with only 1 device (or odd numbers) you would always have cold air pushed in from any gap available when "extracting" and some good warm air being pushed out of the building without recovering when "supplying", because there would be a negative and then positive pressure in the building. And even if the house was air tight (unlikely), then there would be no air flow through the fan, right? :)
Pressure change in the house during the 70sec cycle is trivial (~0.004 bar) but there would be some effect. But then the amount of heat recovered by this unit is also trivial- it would take over 100 years to recover its cost in saved heat. See my main posts for calculation. More importantly, it traps dust, spores, etc (dual direction filters!)
The temperature of the air outside was between 11.5C and 12.5C which was shown after the thermal imaging. The internal air temperature was stated to be around 19C. Having an average of 15.5C for the incoming fresh air is pretty good and the best one could hope for in the larger whole home systems that pass the two streams of air in close proximity to one another in order to transfer heat energy from one to the other. I'd prefer to have seen thermistors measurements of the air temperatures immediately outside the unit for a prolonged period of time in order to get a good comparison instead of using the thermal camera as the thermistors would be more accurate. However, for a quick and somewhat accurate test the thermal camera is good enough.
@@Tensquaremetreworkshop I didn't think about this too... Basically it works well to keep the outside stuff "out", but any pollutant that is filtered coming from indoor would just simply be blown back in once the flow is inverted, true. It is definitely better than an extractor fan by miles, but I am not sure about a decent MVHR. And at least in the uk, unless you have plans to extend on the roof, all the roof space is there to store the MVHR unit and the hoses to direct flow to the rooms, while extracting from another room creating a constant small air flow circulating between supply and exhaust. Ideally, with the exhaust in a bathroom, recovering the best heat, getting rid of the most humidity and even working as odour extraction with fresh air coming from the other rooms... Ideal world I guess
@@capitalinventor4823 Yes, it shows an efficiency of around 40 - 45% at these temperatures. These devices are usually quoted with 24C inside, and -4C outside! Even then it would not make 90%- the best systems only make ~80%, and this method is seriously compromised. More important is the total heat transfer- which is trivial.
@@Alex82pd It is certainly true that air change systems work best when the system is designed into the house build. For one, it needs an hermetically sealed house. Actually, I think an extractor fan is better than this unit. The heat recovery is trivial, as I showed it is >100year payback. And it recycles dust etc. And it is only extracting half the time. And you need to clean filters that only exist to stop the heat exchanger blocking. And it is moderately complex, with moving parts, so there will be a failure rate ( I have a conventional timed extractor, and I am on my third in 10 years...).
Thanks although it has been pointed out I've created a perfect cold bridge with that metal pipe. Should have ripped it out and started again really. It's a TopDon TC001 Not cheap but I was gifted it a couple of years back.
The company would have to have an API available. Hopefully they do and not just have a private API that they use for their own app. What processor they use doesn't actually matter for whether it may be used with Home Assistant. The processor only matters if one wants to overwrite the firmware on the device with a different version.
An ESP32 is a microcontroller with WiFi/bluetooth capability (although I don't think you can use both at the same time). It's cheap (costs a few quid) and commonly used in a lot of devices, such as smart plugs. What's more important is that there's a software framework that allows you to program them by writing a config file (ESPHome), and there's tie in with Home Assistant. So you mentioned that it would be nice to be able to pair two of them to synchronize doing intake/exhaust. If the included app doesn't support that feature, with some reverse engineering, you could conceivably flash them to run ESPHome and automate their synchronized use with HA. You could have a separate temp/humidity sensor and control their activation based on thresholds you set in HA.
Hi Charlie, Very interesting video about air extraction. What's the "efficiency" overall is it about 80% from your heat camera just in terms of temperature in/out or higher on average? I was thinking of installing MVHR with some of them claiming up to 96% efficiency. They all have ducting to be installed which is going to be a pain in my bungalow with the need to keep it all underneath the loft insulation so it stays in the heated envelope and doesn't lose heat through the ducting into the loft space. Or I need bigger insulated ducting. Threading the non insulated plastic corrugated pipe ducting through the existing insulation without compromising it is going to be difficult as it's all installed and boarded over and there are plenty of pipes and other buried obstacles in the way. I did think that perhaps I could get away with only ducting into part of the house and relying on all the rooms having open doors with no zoning (I have a heat pump) so I could perhaps rely on natural mixing. Your single fans are another possibility. The main problem I have is moisture and CO2 build up as the house is pretty well sealed. At the moment I'm having to open windows and external does to do a quick air exchange but I also lose heat in the process.
It's a breeze in a bungalow. Do it once and do it well starting centrally and covering all rooms. If the loft is boarded keep the ducting over and insulate them separately. Might also be worth adding a few rolls of some type of breathable superfoil insulation on the underside of the rafters to increase its thermal performance.
I agree with @@m.o.2085 mvhr is brilliant for bungalows particularly as yours is so well sealed. A lot of people have previously commented that they've installed PIVs in their bungalows to great effect. You would need to think about where all that moisture is going though with a PIV given how well sealed your place is.
ESP32 sounds like it will be good with Home Assistant 😉 I’m still rocking my PIV having a chimney makes it way to shift air in the exchange, I’ve added it to Home Assistant and turned it on max it comes on for 2 hours full blast in the day and two dehumidifiers at night one downstairs and one upstairs all using HA 😉 PS now my kitchen fan extracts if the fire alarm in the kitchen or dining room sound the kitchen fan is massive I got a iCON60 due to the iris shutter as the other extractor was letting out all the hot air, now I can just control this with Siri and HA 😊
I have mold, crazy damp readings and relative humidity like the tropics and a bad smell. I was advised to get units like this and an insane moisture barrier on the walls but cant afford that system and I think it is overkill. Would two or three of these units cure the humidity, how much power do they use and are the electrics chased and connected to the ring mains or is all new wiring involved ?
If you haven't already got a dehumidifier it is a great asset... they work better in warmer rooms, but are a massive help to reduce damp... we have a shower room with no extractor fan and still are able to effectively dry washing with only a 60w towel radiator and dehumidifier (no damp walls).👍
Interesting, but the issue with these is that unless you install at least two then their effectiveness is likely to be very localised, especially if doors are shut. Im interested in split air conditioning units that use heat pump technology, many of these dehumidify, so you can heat, cool and dehumidify making them more versatile, anyone any thoughts on this?
Looking for just a one way filtered flap for my kitchen for when the powerful extractor hood is switched on. Its currently pulling from any open window but I'd rather install a local fresh air supply in the kitchen but can't find anything suitable? Any ideas anyone?
Looks like its simply blowing the internal warm air through a ceramic thermal store, then brings it back in when reversing the fan? Seems a good simple cheap idea - being sold for way too much.
@@ricos1497 The ESP32 isn't the worst way to go about it really, problem here is possible limited firmware. This is the same chip used in the sonoff devices... they are sub £1 chips.
trying to find a solution for my mobile home (in USA), especially to get fresh air in while keeping the cool/warm air inside. just not many solutions for thin walls
Can I take us back to PIV units, I had one installed two years ago, but it made zero difference to the amount of condensation we experienced in our house. Why might that be? I had heard such great things and am so gutted. Really intrigued by this! Is this something you would use instead of a standard kitchen extractor fan? Ours is incredibly loud!
Friend who works at biggest manufacturer of PIV told me they're useless for most people, apparently very few properties actually benefit so I stopped looking.
Couple of parts to this PIV is great but the air needs to go somewhere. Sources of water need there own way of getting rid of moisture ie water source areas need there own,bathrooms wash area kitchen areas need there own extraction devices. I use to run my PIV all the time but in winter the heating went on too much as it was cold it did drop the humidity though I saw 37% one night I have a chimney so I’ve got a permanent opening and you have got to seal the loft hatch to stop it just circulating I used fire form to seal the wires going through the ceiling just to make it harder for the air to return to the loft basically forcing it to use my chimney as that’s the path of least resistance. In the end I turned it off got two dehumidifiers not the compressor kind so I can get a bit of heat from them at night and keep condensation down when we sleep in the morning the PIV is turned on max to do an air exchange for two hours and then shuts off all automagically through Home Assistant.
PIV needs places for the air to exit so vents/window vents in the affected areas. Possibly even leaving the window slightly open if not windy. Also PIV won't work that well if the house is very leaky as it'll just blow out the nearest big hole. You need to be able to control the ventilation for each room. Doors need to have a finger width gap underneath for air flow. Also they work by a temperature difference between outside and inside. The inside air needs to be warmer than the outside air otherwise they work in reverse making it damper inside. For this reason they are more effective at night. They are also not a replacement for proper extraction fans in kitchens and bath/shower rooms. These need to be powerful and have an overrun for a good amount of time to dry the room after you've finished making moisture.
Even more- 1) This unit contains a filters (unlike normal extractors)- presumably to protect the heat exchanger from dust. Problem is, the air flow is reversed every 70 seconds, so most of the dust trapped on the way out will be blown back in again (did no-one explain to the designer how filters work?) So, all the dust, spores, etc are retained in your home. And you get to clean the filters. Not very often, because this reversing air flow will keep them clean! 2) In sleep mode, this runs at 15l/min. But the capacity of the tube is ~ 6l - so a third of the air is just being returned to the house! 3) Energy consumption- the claim is it uses less than 20% of the power the Kair uses for the same airflow. Does this seem likely? Kair recovery claim 'up to 86%' this one 'up to 90%' - at around half the price... As a design engineer, I am constantly amazed that ideas that ignore the laws of physics come to market.
Interesting points you have made.. It appears that the Kair product is a shell and tube heat exchanger, so no reversal of direction, but a potential issue is the cross contamination of exhaust and supply being relatively close. Another issue with the Zephyr is that when it is in extract mode, there is no heat recovery unless it is paired with a secondary unit, and as you have indicated around 40% of the extracted air will find its way back into the house, so 'extraction efficiency' is unlikely to be great! 😂 I might be mistaken, but think that gas boiler exhaust flues use a twin pipe construction to exhaust and supply air through the same opening, so would be interested to see more ventilation systems utilise this (like kair) - surely it would be a bit more efficient than the reversal method?
@@aesopshair6690 I had a whole home HRV in my last house and it use a single point for the input and output. They got around the cross contamination of the supply by extending both pipes slightly from the house and bending the exhaust downwards. The vent cover also helped to keep the supply and exhaust from combing. From the video I noticed that the Kair product appeared to extend further out from the house and I'm guessing that they probably do something similar. There's going to be cross contamination on this product because there doesn't seem to be a pause between the supply and exhaust cycles. Some of the air that is being blown out will be caught when the product turns to supply mode. A simple two or five second delay after the fan stops spinning between the two modes would have greatly reduced this risk.
@@aesopshair6690 The Zephyr relies on stored heat between in and out cycles. This has issues, some of which I have addressed. Co-axial heat exchanges are, as you say, used for boiler systems. They benefit from the hottest exhaust meeting the final inlet- it slopes in matching temperature (flow in opposite directions), making it fairly efficient. The problem is that you need a long duct, but it can be done. Since thin polythene can be used for the tubing (little pressure differential) it can be very cheap. The most efficient system uses rotating plates- but that is only practical for a large centralized system. I have some doubts about the power consumption on the zephyr - they claim about 12% of what the Kair one uses. Seems unlikely...
@@CharlieDIYte Not sure what relevance this has- the dust retention would not be affected by such a pause. It is probably done to allow the fan (and air) to stop, so avoiding braking power being applied.
Ronan if you scroll down to Andy Mac's comment you'll see how his has fixed the mould and damp in his outdoor room. Check out my video on this ruclips.net/video/NbtijHKy2Vo/видео.htmlsi=e2GhJqRymLVh2gGt You could install 2 fans to work as a pair to maximise air circulation, or consider installing a PIV.
A metal duct acts as a heat duct- avoid. Strangely, the motor is mounted on the cold side- meaning its heat is lost... The efficiency claim is 'up to 90%' - but zero is up to 90%! cannot help feeling that a really good system would graph performance against differential temperatures- what have they got to hide? Update- research suggests this type of recovery has a max efficiency of 80% - and that is best case... Your test of temperatures suggest 40-50% efficiency. A 'buyback' calculation would be interesting... There are two reasons for air change. The minor one is for odour extraction, the main one is for air to breathe. The latter is not really helped by bathroom extractors, the door tends to be shut when not in use, and only occupied for a few minutes. The obvious place to do the air change in modern 'one room living' is the cooker extractor. It is also where the air will be hottest when the hotplates are in use! In this case a plate heat exchanger would probably be the way to go.
I do not understand gow this system could work with multiple units and still recover heat of some are only extracting and some only supplying? How the heck would the heat be recovered?
Not completely useless, just less effective. Only as it’s controllable whereas ventilation in a leaky house is sporadic. But yeah you’ll see better results in a more airtight home
If it pushes air out of the house for a certain period (negative intern pressure) and then pulls air in for a certain period (positive internal pressure), where is that extra air coming from? On the out phase - cold winter air will be pulled into your house, probably through windows and doors, on the in phase, your nice warm internal air will be pushed out through the same route. Pointless! Much better to get a single room system with split or concentric air ducts (like the in and out of a gas flue) which can recover the heat by a counter flow method and does not change the air pressure inside the room and encourages draughts.
Frankly I do not like them. They might look nice but they really have bad efficiency. You can easily DIY HRVs with much better efficiencies although it will take effort to make them look good and they certainly won't be compact.
@@JohnoLapseyes quality of air is a huge factor as opposed to living in a toxic box , there is an old saying that goes “ pay for your health now or pay later “
In response to your previous core drill comments about me that you missed, using the proper tools for the job you won't have the problems you described. Hard brick! That's why they use it to drill for oil.
Where I live most people tend to use the method as shown in this video due to the hard brick. A core drill takes roughly 2 hours to get through but as he says, it can be done in 20-30mins with multiple small holes. I do have all the kit to drill a core hole but it just takes too long in hard brick areas. I'll usually start off a hole with a core drill to get a neat outline then switch to smaller bits. In softer brick, block or concrete I would just core drill the whole way
Great video as per usual Charlie! Thanks for the shout-out. Bit of an update on mine - bear in mind mine isn't in a domestic environment, it's in a studio. The Kair MVHR fixed my mould and damp issues, which was my primary objective. However since my studio isn't heated 90% of the time I doubt the heat recovery side is doing much and in reality it's destroyed my soundproofing 😂😭. A future project will be to fix this properly but it's not particularly urgent. Sadly that will probably involve removing the MVHR since the simultaneous 'IN & OUT' through a single hole really complicates things when it comes to making a soundproof enclosure. But it's been running on trickle for over a year with no issues and more importantly my studio is now mould-free. The BSK system looks great! 👍
Thanks for the great update Andy. Yes it's a nice bit of kit but the Kair seems to be pretty tech/ hardware heavy in comparison. Possibly more efficient on the heat recovery, or maybe the BSK is just a brilliant design? Who knows. I'll be really interested to see how you solve this whilst keeping the studio sound proof. 👊
Thanks Charlie, love your videos. I put 3 of these BSKs into our poorly insulated 1990s 3-bed semi. Definitely helped with air quality, humidity and winter window condensation (however it certainly didn’t eradicate the condensation). We have the humidity auto-boost switched on and (while it's useful) we find the beeper/sounder quite annoying when it changes back and forth between normal and boost. Especially at night. So I plugged up the sounder with a little toilet paper and glue! Worked perfectly. 😊
All the best from Ireland.
Thanks, that's great feedback. How did you set them up in terms of working together? It's very hard to eradicate condensation particularly if you've got single glazed windows. You can see the difference here ruclips.net/user/shortslQv5FIZd9Qc?feature=share - I don't think I'll ever eradicate condensation in that bay! PIVs seem to be the answer for that though
@CharlieDIYte Hi again, Charlie. To answer your question: I set up 2 units in the 2 occupied bedrooms in parallel with each other. And the 3rd unit running opposite them (in the upstairs home office). Theory was to encourage continuous air movement upstairs. In practice, I agree with some of your other viewers' comments and feel the 3 are not strong enough to push ALL the air around our leaky old house. But they definitely helped us, I enjoyed doing the work and l learned a thing or two at it. So 'jobs a goodun' as you Brits like to say. I'm smiling here at your positivity: that condensation on the window = a free dehumidifier :-). I like that! All the best.
Lots of informative and well presented content across many videos so thanks.
Thanks so much Tim. Really appreciate that and I'm chuffed you've found my videos useful. 👊
I used BPC to design a whole house MHVR on my newbuild. The design worked perfectly, very little wastage in pipe runs. Fantastic humidity/temperature control throughout the building. No cold spots in corners of rooms with a gentle circulation of air
You made a maximally effective metal cold bridge between outer wall and inner wall with the galvanised ducting. You can see it in the IR shots from 15:18 onward.You probably should have swapped that out for the plastic one.
I did worry about that. Don't forget it's completely insulated behind by the foam though.
@@CharlieDIYte Not going to argue with you, as you have all the experience here. I just looked at the IR footage and immediately spotted the colder blue ring, compared to the surrounding wall. Maybe it is not as dramatic as it looks in real life.
I was thinking exactly the same. as soon as I saw the metal ducting. But absolutely loved the method of joining the duct to the membrane inside, genius. Oh and a perfect chain drill instead of a core drill, work of art. 👍
@@stephen-boddyI know. I was properly kicking myself for doing that. The important thing is I don't think anyone else will be making the same mistake. I'm not convinced their telescopic option is brilliant either though as you've got leakage between the pipes mid way though but as you say, better that than having a cold bridge from front to back.
A great video. We have installed MVHR as we did our massive bungalow reonovation and it has made a huge difference to the house. It was quite hard for us to do that so something like this for older properties are a great option.
Can I ask what system you had?
Nice one Charlie, I fitted one of those (not that model, a 4" one) and it failed within 6 months. Was very close to getting one of those 6" but the reviews were pretty rare, I'll be keen to know if it lasts a fair while. Keep up the good work 👍
Love the reference to keyboard warrior people saying you should use a core drill.. - Personally, i love that you show people how to do this with stuff they actually might already have in their tool kit! I've said it before, but your videos are an inspiration and yours (along with Mr Mac's) jump to the top of my viewing list when they appear. Looking forward to the next video!
Another channel worth watching is 'the aiden project' if just for entertainment 🤣.. always honest about his mistakes.
@@aesopshair6690 Thanks, will check it out.. - Actually, thats another thing i really like about Charlie's videos.. He doesnt try to make out he is something he is not. He owns up when he made a mistake, and gives full disclosure as to his involvement with a company. "they gave me this, and i get to keep it, but they dont have any editorial say" - and in the case of this video, "i bought a pipe, but didnt need to" - then makes the best of the situation, often to advantage. The internet needs more channels and RUclipsrs like Charlie.
Thanks Martin, can't tell you how much I appreciate that. Yes the mistakes are a very important part of it for me. Take them out and it's not real life 😉👊
OK, I have run the numbers. At its highest setting (60 cu m /hr) if you leave it extracting for 5mins (10 mins total, as it only extracts half the time) then if it is freezing outside and 20C inside you will have saved 18Whrs of heat. Which, with electric direct heat will cost you around 0.48p (gas or heat pump around a quarter of that). Used twice a day (but savings only in Winter), that will be a buyback of just over 100 years... So not for bathrooms then...
Air change for the rest of the house? Well, you will need 2 or 3 running flat out to meet recommended minimum air change- and a hermetically sealed house. Do you run out of breathing air at the moment? If not, it is getting in somewhere, and that would need to be sealed.
Night mode is a quarter the flow, so eight hours a night for say 120 freezing equivalent nights (generous) is about £1.30 worth of gas a year. Less the 26p it would cost to run it. More than 100 years then. And assuming that it needs no maintenance, like filter cleaning.
This is gold! Thanks for your work. Questioning why we put them in most new build apartments now
@@tommotube It looks good on the adverts... Having said that, centralized systems can do better. What I can get no-one to answer is- why are we using air to water heat pumps in this country? The rest of the world uses air to air. If you do that, you can couple your air change system to your heating system, use the same fan and add heat all in one place. Heating companies, if you have not thought of that, you can have the idea for free.
Thanks, brilliant analysis. Yes I hear what you say on the payback. Trouble is if I ran that analysis on everything I do in this old cottage I'd never do any renovations 😉 I'll never get the money back on the ufh and wall insulation but it gives us joy every time we go in there particularly in these cold months - it's typically 2 degrees warmer in there than the heating is set to and I guess you'd say it's transformed the thermal footprint of the house.
@@CharlieDIYte Sorry, I cannot help analyze such items- especially when the specification is vague and rings alarm bells. For many years I was a consulting engineer, often asked to appraise a design before it went to market. It was alarmingly common for the physics involved not to be examined. In some cases, the objective was actually impossible, and no-one had spotted it. This item is one that works, but so poorly that it is not worth its cost never mind its installation. It also has issues with dust retention and maintenance. If ventilation is needed, a simple extractor is better- spend the difference on draft proofing. The claims made are wild- the best heat recovery systems are, at best, 80% (often measured with ~24C inside and ~-5C outside) and I am deeply suspicious of the power requirements- they are around a tenth of the Kair unit... Heat recovery can work, but it requires a whole house approach designed into the build.
BTW, removing that metal duct ( a serious thermal bridge) will save more heat than the unit.
@@Tensquaremetreworkshop No need to apologise. You're absolutely right - and this calls for a follow up video at some point. Yes I'm painfully aware of the issue with that duct - I've created a flawless cold bridge when I'm always at pains to tell people the danger of cold bridging. Crazy how you miss the most obvious things when you're mired in the details of a project. It'll need some thought though as that telescopic pipe they provide isn't perfect either - it needs siliconing to prevent moisture getting through the gap between the two pipes. Yes the dust filter is ridiculous, again something I should have made more of a point of. I did at least highlight the issue if not the problem of that dust being blown back in the supply phase.
As someone who lives in perpetual frigidity due to their wife opening all the windows to “let the house breathe” even in the dead of winter, I’ve never clicked “Save to Watch Later” so fast.
😂
😂😂😂
She's right though.. But maybe not too often 😉
@@CharlieDIYte Oh she's absolutely right (I quickly learnt she almost always is). And coming from a country which takes ventilation much more seriously than we do (even their Soviet-era tower blocks have proper chunky wind-shielded window vents), she couldn't help but laugh at our piddly trickle vents.
So I have both her and yourself to thank for opening my eyes to the importance of fresh air (not just to avoid damp issues but also the effects of CO2 buildup on cognition and mental health), and leading me down the rabbit hole of PIV, MVHR, etc. 🙂
Great video; very informative !
The "Tiny Off-Grid House Research" interest in decentralized ventilation is not primarily focused on just providing ventilation, or heating the incoming fresh air but more importantly the removal of moisture and humidity from the indoor air space which can facilitate the growth of microbial molds and fungi which can be harmful to the occupants respiratory health and cause structural damage to the house
True! As you can see from my calculations (main post) the heat recovery is trivial. Humidity and CO2 control is much more important. Worth buying a version that monitors that.
I fit the same unit in my garden office as the CO2 levels were quote high, I switched the filter out for HEPA, but does a good job. Dont really notice any reduction in heat/cooling in the room. Planning to do the same in a couple rooms within the house soon.
Only things missing is integration with Home Assistant, and I wish the app could do full scheduling instead of just an entire day.
The filter is to protect the unit, not you! It is actually detrimental - it traps dust, spores, etc on the way out, and then blows them back into the room when it reverses. (the outside air is much cleaner than the internal air- use a particulate meter if you do not believe me.)
Nice video. We fitted the same model around a month ago. Quite impressed with performance so far.
Thanks. Glad to hear that. You and me both 😉
Looking forward to a longer term review. Also go buy another one and let us know how the paired function works. Then I just gotta find a decent electrician to put the mains wire in.
Cut into the render with a Stanley knife around the external hole to avoid tearing the render finish. Regardless of whether you’re chain drilling or using a core bit in render.
So now we just need to install two or three of these in every old house in the UK and the mould problems would be sorted. Would be good to see more people install these to get a buzz around them and so the market grows.
This is exactly the video I needed!
Hi Charlie Contentious topic , which in a way highlights the difference in how we live in the modern age . The more we do to increase the temperature in our homes the more challenges we encounter , the main difference is the change in the way we actually build and design our homes . Certainly compared to the terrace house I grew up in my youth back in the early 50s . A fire place in every room and single glacéd sash windows that leaked like sieves . And I think here we have a possible compromise that is worth considering , I now live in a well insulated double glazed detached house . Yet we also have a wood burning stove , that is only used in the coldest of weather . Yet it sits there providing a passive form of ventilation , this ability I think we have lost sight of with the passing of time . Yes the powers that be , seem determined to prevent the use of wood burners . But even if this came to pass , I would still keep ours for its ventilation properties, and have a bunch of dried flowers inside . Kind regards as always .
If you are able to run your log-burner without opening a window, that suggests you have other sources of ventilation too. There are probably dual air vents to the fireplace area.
So true. We also have a wood burner which is now almost redundant since we installed under floor heating. But you're absolutely right in well insulated double glazed houses it's critical to have some form of ventilation - trickle or otherwise. I suppose the only question is whether in the absence of trickle vents, your open wood burner is providing sufficient ventilation. Better than nothing though!!
@@CharlieDIYte Log burners leak like a sieve- unless you have a flue valve. And there has to be air ingress to allow it to work. Your heat loss from this will almost certainly. exceed that fan recovery. To save heat, a flue valve would have been a better purchase...
Is a 3 degree difference between outside air and supply air really worth it? Would be interesting to see how quickly the core cools down
That was roughly the midway point between the 2 temperatures. If, when it is much colder, it can still deliver the midway point, that would be a huge saving.
[Pedant Mode] Humidity drop from 56 to 48 is 8 percentage points - that actual improvement is 14.5%. I'll get my coat! ;-) [leaves quietly]
Never apologize for pedantry! Especially to the 'its good enough' brigade...
Fair point 🤦😂
Great video. Can you tell me about the efficiency of this system vs a centralised unit?
Charlie, you have at last caught up with single unit heat recovery ventilation. I was using these 20 years ago.
and yet they still not know about by many. Not sure why.
Yes it took me a while! Great work - a man before your time - or do you live outside the UK? 😉
A good video, thank you. Have you ever done one on the thermal imaging dongle thingy?
As a seasoned pro who has drilled thousands if not millions of holes in his time you're doing it right. Core drills suck, especially in hard brick.
Thanks, and no I haven't done a video on the TopDon TC001. I should though. It's a great bit if kit.
a supply temperature of 14.5/15 degC with 14 degC outside does not show much heat recovery really. The way to test the heat recovery capability of this device would be with some colder weather, with something like 5 or 0 degC outside, where I would expect the supply during the 7 minutes cycle to remain at least above 10deg C, possibly higher, and see how it goes down while the thermal energy stored in the ceramic mesh depletes.
Also, another thing to consider is that unless you work with 2 devices meshed in "push-pull" configuration, with only 1 device (or odd numbers) you would always have cold air pushed in from any gap available when "extracting" and some good warm air being pushed out of the building without recovering when "supplying", because there would be a negative and then positive pressure in the building. And even if the house was air tight (unlikely), then there would be no air flow through the fan, right? :)
Pressure change in the house during the 70sec cycle is trivial (~0.004 bar) but there would be some effect. But then the amount of heat recovered by this unit is also trivial- it would take over 100 years to recover its cost in saved heat. See my main posts for calculation. More importantly, it traps dust, spores, etc (dual direction filters!)
The temperature of the air outside was between 11.5C and 12.5C which was shown after the thermal imaging. The internal air temperature was stated to be around 19C. Having an average of 15.5C for the incoming fresh air is pretty good and the best one could hope for in the larger whole home systems that pass the two streams of air in close proximity to one another in order to transfer heat energy from one to the other. I'd prefer to have seen thermistors measurements of the air temperatures immediately outside the unit for a prolonged period of time in order to get a good comparison instead of using the thermal camera as the thermistors would be more accurate. However, for a quick and somewhat accurate test the thermal camera is good enough.
@@Tensquaremetreworkshop I didn't think about this too... Basically it works well to keep the outside stuff "out", but any pollutant that is filtered coming from indoor would just simply be blown back in once the flow is inverted, true.
It is definitely better than an extractor fan by miles, but I am not sure about a decent MVHR. And at least in the uk, unless you have plans to extend on the roof, all the roof space is there to store the MVHR unit and the hoses to direct flow to the rooms, while extracting from another room creating a constant small air flow circulating between supply and exhaust. Ideally, with the exhaust in a bathroom, recovering the best heat, getting rid of the most humidity and even working as odour extraction with fresh air coming from the other rooms... Ideal world I guess
@@capitalinventor4823 Yes, it shows an efficiency of around 40 - 45% at these temperatures. These devices are usually quoted with 24C inside, and -4C outside! Even then it would not make 90%- the best systems only make ~80%, and this method is seriously compromised. More important is the total heat transfer- which is trivial.
@@Alex82pd It is certainly true that air change systems work best when the system is designed into the house build. For one, it needs an hermetically sealed house. Actually, I think an extractor fan is better than this unit. The heat recovery is trivial, as I showed it is >100year payback. And it recycles dust etc. And it is only extracting half the time. And you need to clean filters that only exist to stop the heat exchanger blocking. And it is moderately complex, with moving parts, so there will be a failure rate ( I have a conventional timed extractor, and I am on my third in 10 years...).
Excellent video.
Nice MacGyver trick with the tape at 7:25
Job well done again
What kind of thermal imaging tool or lens do you use ?
Thanks although it has been pointed out I've created a perfect cold bridge with that metal pipe. Should have ripped it out and started again really. It's a TopDon TC001 Not cheap but I was gifted it a couple of years back.
Could I replace an existing ceiling extractor fan (which has a short soft walled run to outside) with one of these?
Have installed the BSK units our house (four of them), they are not intended to extract moist air from a bathroom, from a shower say.
an esp32? can we connect this to home assistant? This unit is very interesting. Thanks for sharing!
Potentially with the ESPHome integration
The company would have to have an API available. Hopefully they do and not just have a private API that they use for their own app. What processor they use doesn't actually matter for whether it may be used with Home Assistant. The processor only matters if one wants to overwrite the firmware on the device with a different version.
An ESP32 is a microcontroller with WiFi/bluetooth capability (although I don't think you can use both at the same time). It's cheap (costs a few quid) and commonly used in a lot of devices, such as smart plugs. What's more important is that there's a software framework that allows you to program them by writing a config file (ESPHome), and there's tie in with Home Assistant. So you mentioned that it would be nice to be able to pair two of them to synchronize doing intake/exhaust. If the included app doesn't support that feature, with some reverse engineering, you could conceivably flash them to run ESPHome and automate their synchronized use with HA. You could have a separate temp/humidity sensor and control their activation based on thresholds you set in HA.
They actually do synchronise by design so no need for all of that.
Hi Charlie,
Very interesting video about air extraction. What's the "efficiency" overall is it about 80% from your heat camera just in terms of temperature in/out or higher on average?
I was thinking of installing MVHR with some of them claiming up to 96% efficiency. They all have ducting to be installed which is going to be a pain in my bungalow with the need to keep it all underneath the loft insulation so it stays in the heated envelope and doesn't lose heat through the ducting into the loft space. Or I need bigger insulated ducting.
Threading the non insulated plastic corrugated pipe ducting through the existing insulation without compromising it is going to be difficult as it's all installed and boarded over and there are plenty of pipes and other buried obstacles in the way.
I did think that perhaps I could get away with only ducting into part of the house and relying on all the rooms having open doors with no zoning (I have a heat pump) so I could perhaps rely on natural mixing.
Your single fans are another possibility.
The main problem I have is moisture and CO2 build up as the house is pretty well sealed. At the moment I'm having to open windows and external does to do a quick air exchange but I also lose heat in the process.
It's a breeze in a bungalow. Do it once and do it well starting centrally and covering all rooms.
If the loft is boarded keep the ducting over and insulate them separately.
Might also be worth adding a few rolls of some type of breathable superfoil insulation on the underside of the rafters to increase its thermal performance.
I agree with @@m.o.2085 mvhr is brilliant for bungalows particularly as yours is so well sealed. A lot of people have previously commented that they've installed PIVs in their bungalows to great effect. You would need to think about where all that moisture is going though with a PIV given how well sealed your place is.
ESP32 sounds like it will be good with Home Assistant 😉 I’m still rocking my PIV having a chimney makes it way to shift air in the exchange, I’ve added it to Home Assistant and turned it on max it comes on for 2 hours full blast in the day and two dehumidifiers at night one downstairs and one upstairs all using HA 😉 PS now my kitchen fan extracts if the fire alarm in the kitchen or dining room sound the kitchen fan is massive I got a iCON60 due to the iris shutter as the other extractor was letting out all the hot air, now I can just control this with Siri and HA 😊
Love that!
given that the membrane isn't all that stiff, the oscilo-tool probably wouldn't have damaged it. also, d.i-wife. love it!!
Hi Charlie, Good to see your thoughts on heat recovery system, always full of good tips and ideas, great video, catch you soon, take care
Love the idea but I'm not certain the loss in insulation is offset by the meagre returns offered by the heat exchanger.
I have mold, crazy damp readings and relative humidity like the tropics and a bad smell. I was advised to get units like this and an insane moisture barrier on the walls but cant afford that system and I think it is overkill. Would two or three of these units cure the humidity, how much power do they use and are the electrics chased and connected to the ring mains or is all new wiring involved ?
If you haven't already got a dehumidifier it is a great asset... they work better in warmer rooms, but are a massive help to reduce damp... we have a shower room with no extractor fan and still are able to effectively dry washing with only a 60w towel radiator and dehumidifier (no damp walls).👍
Did the metal ducting require an earth connection? As the cable is so close
The unit is sheafed in plastic and the plastic pipe I slotted in prevents any contact with the duct.
Interesting, but the issue with these is that unless you install at least two then their effectiveness is likely to be very localised, especially if doors are shut.
Im interested in split air conditioning units that use heat pump technology, many of these dehumidify, so you can heat, cool and dehumidify making them more versatile, anyone any thoughts on this?
Looking for just a one way filtered flap for my kitchen for when the powerful extractor hood is switched on. Its currently pulling from any open window but I'd rather install a local fresh air supply in the kitchen but can't find anything suitable? Any ideas anyone?
Looks like its simply blowing the internal warm air through a ceramic thermal store, then brings it back in when reversing the fan? Seems a good simple cheap idea - being sold for way too much.
But, there's an app. They could have doubled the cost with AI and blockchain.
@@ricos1497 The ESP32 isn't the worst way to go about it really, problem here is possible limited firmware. This is the same chip used in the sonoff devices... they are sub £1 chips.
trying to find a solution for my mobile home (in USA), especially to get fresh air in while keeping the cool/warm air inside. just not many solutions for thin walls
Can I take us back to PIV units, I had one installed two years ago, but it made zero difference to the amount of condensation we experienced in our house. Why might that be? I had heard such great things and am so gutted.
Really intrigued by this! Is this something you would use instead of a standard kitchen extractor fan? Ours is incredibly loud!
Friend who works at biggest manufacturer of PIV told me they're useless for most people, apparently very few properties actually benefit so I stopped looking.
Problem with PIV is getting the air movement to where it’s actually needed, maybe you can shut doors and open/close trickle vents to assist.
Yes the idea with these units is you just run them 24/7 at low speed.
Couple of parts to this PIV is great but the air needs to go somewhere. Sources of water need there own way of getting rid of moisture ie water source areas need there own,bathrooms wash area kitchen areas need there own extraction devices.
I use to run my PIV all the time but in winter the heating went on too much as it was cold it did drop the humidity though I saw 37% one night I have a chimney so I’ve got a permanent opening and you have got to seal the loft hatch to stop it just circulating I used fire form to seal the wires going through the ceiling just to make it harder for the air to return to the loft basically forcing it to use my chimney as that’s the path of least resistance.
In the end I turned it off got two dehumidifiers not the compressor kind so I can get a bit of heat from them at night and keep condensation down when we sleep in the morning the PIV is turned on max to do an air exchange for two hours and then shuts off all automagically through Home Assistant.
PIV needs places for the air to exit so vents/window vents in the affected areas. Possibly even leaving the window slightly open if not windy. Also PIV won't work that well if the house is very leaky as it'll just blow out the nearest big hole. You need to be able to control the ventilation for each room. Doors need to have a finger width gap underneath for air flow. Also they work by a temperature difference between outside and inside. The inside air needs to be warmer than the outside air otherwise they work in reverse making it damper inside. For this reason they are more effective at night.
They are also not a replacement for proper extraction fans in kitchens and bath/shower rooms. These need to be powerful and have an overrun for a good amount of time to dry the room after you've finished making moisture.
Even more-
1) This unit contains a filters (unlike normal extractors)- presumably to protect the heat exchanger from dust. Problem is, the air flow is reversed every 70 seconds, so most of the dust trapped on the way out will be blown back in again (did no-one explain to the designer how filters work?) So, all the dust, spores, etc are retained in your home. And you get to clean the filters. Not very often, because this reversing air flow will keep them clean!
2) In sleep mode, this runs at 15l/min. But the capacity of the tube is ~ 6l - so a third of the air is just being returned to the house!
3) Energy consumption- the claim is it uses less than 20% of the power the Kair uses for the same airflow. Does this seem likely? Kair recovery claim 'up to 86%' this one 'up to 90%' - at around half the price...
As a design engineer, I am constantly amazed that ideas that ignore the laws of physics come to market.
Interesting points you have made.. It appears that the Kair product is a shell and tube heat exchanger, so no reversal of direction, but a potential issue is the cross contamination of exhaust and supply being relatively close.
Another issue with the Zephyr is that when it is in extract mode, there is no heat recovery unless it is paired with a secondary unit, and as you have indicated around 40% of the extracted air will find its way back into the house, so 'extraction efficiency' is unlikely to be great! 😂
I might be mistaken, but think that gas boiler exhaust flues use a twin pipe construction to exhaust and supply air through the same opening, so would be interested to see more ventilation systems utilise this (like kair) - surely it would be a bit more efficient than the reversal method?
@@aesopshair6690
I had a whole home HRV in my last house and it use a single point for the input and output. They got around the cross contamination of the supply by extending both pipes slightly from the house and bending the exhaust downwards. The vent cover also helped to keep the supply and exhaust from combing. From the video I noticed that the Kair product appeared to extend further out from the house and I'm guessing that they probably do something similar.
There's going to be cross contamination on this product because there doesn't seem to be a pause between the supply and exhaust cycles. Some of the air that is being blown out will be caught when the product turns to supply mode. A simple two or five second delay after the fan stops spinning between the two modes would have greatly reduced this risk.
@@aesopshair6690 The Zephyr relies on stored heat between in and out cycles. This has issues, some of which I have addressed. Co-axial heat exchanges are, as you say, used for boiler systems. They benefit from the hottest exhaust meeting the final inlet- it slopes in matching temperature (flow in opposite directions), making it fairly efficient. The problem is that you need a long duct, but it can be done. Since thin polythene can be used for the tubing (little pressure differential) it can be very cheap. The most efficient system uses rotating plates- but that is only practical for a large centralized system.
I have some doubts about the power consumption on the zephyr - they claim about 12% of what the Kair one uses. Seems unlikely...
There is a few seconds' delay between each cycle. I'm cross I didn't show that in the video.
@@CharlieDIYte Not sure what relevance this has- the dust retention would not be affected by such a pause. It is probably done to allow the fan (and air) to stop, so avoiding braking power being applied.
Would anyone know how well these perform in the cold winter months with a low temp outside and a bedroom that is prone to condensation thanks.5
Ronan if you scroll down to Andy Mac's comment you'll see how his has fixed the mould and damp in his outdoor room. Check out my video on this ruclips.net/video/NbtijHKy2Vo/видео.htmlsi=e2GhJqRymLVh2gGt You could install 2 fans to work as a pair to maximise air circulation, or consider installing a PIV.
I am right in thinking this could be used in a bathroom and toilet instead of a standard extractor fan set up?
No, they are not designed to be used in bathrooms. They cannot cope with the quantity of moist air that is generated.
A metal duct acts as a heat duct- avoid.
Strangely, the motor is mounted on the cold side- meaning its heat is lost...
The efficiency claim is 'up to 90%' - but zero is up to 90%! cannot help feeling that a really good system would graph performance against differential temperatures- what have they got to hide?
Update- research suggests this type of recovery has a max efficiency of 80% - and that is best case... Your test of temperatures suggest 40-50% efficiency. A 'buyback' calculation would be interesting...
There are two reasons for air change. The minor one is for odour extraction, the main one is for air to breathe. The latter is not really helped by bathroom extractors, the door tends to be shut when not in use, and only occupied for a few minutes. The obvious place to do the air change in modern 'one room living' is the cooker extractor. It is also where the air will be hottest when the hotplates are in use! In this case a plate heat exchanger would probably be the way to go.
Came here to say the same!! In the thermal camera image you can see that cold, dark ring. The plastic would have worked better I think.
"The minor one is for odour extraction"
Not in my bathroom
@@ricos1497 You prefer asphyxiation to a bad smell?
I do not understand gow this system could work with multiple units and still recover heat of some are only extracting and some only supplying? How the heck would the heat be recovered?
Because they're still working in 70 second cycles but some are expelling whilst others are supplying.
This is only good in well insulated rooms from my research. This should be mentioned. In a leaky house this is useless.
Not completely useless, just less effective. Only as it’s controllable whereas ventilation in a leaky house is sporadic. But yeah you’ll see better results in a more airtight home
So, it doesn’t work.
The metal pipe is not good for insulation
Probably fair enough but it's got expanding foam behind and 3/4 of it is sheafed in the plastic I should have used.
the difference made by the 'ceramic gizmo' is pitiful. Thanks, at least I know what a waste of time and money it is
If it pushes air out of the house for a certain period (negative intern pressure) and then pulls air in for a certain period (positive internal pressure), where is that extra air coming from? On the out phase - cold winter air will be pulled into your house, probably through windows and doors, on the in phase, your nice warm internal air will be pushed out through the same route. Pointless!
Much better to get a single room system with split or concentric air ducts (like the in and out of a gas flue) which can recover the heat by a counter flow method and does not change the air pressure inside the room and encourages draughts.
Basically, if you have a high level of air-tightness in your house (which is something you should aim for), this system will not work.
Nice idea, but too expensive, too noisy and not efficient enough.
Frankly I do not like them. They might look nice but they really have bad efficiency. You can easily DIY HRVs with much better efficiencies although it will take effort to make them look good and they certainly won't be compact.
The efficiency of this unit vs the payback?….. I think I’ll wait a few years until they’re more standard and then cheaper.
Depends if you value just living in a more comfortable place. I can't put money on that.
What's the payback of a new kitchen?
@@JohnoLapseyes quality of air is a huge factor as opposed to living in a toxic box , there is an old saying that goes “ pay for your health now or pay later “
Probably 10-15 years. Maybe just in time for the unit to fail and need replacing.
In response to your previous core drill comments about me that you missed, using the proper tools for the job you won't have the problems you described. Hard brick! That's why they use it to drill for oil.
have you asked someone to get you a life for christmas?
@@solidus784you comment has taken a lot of thought!
Where I live most people tend to use the method as shown in this video due to the hard brick. A core drill takes roughly 2 hours to get through but as he says, it can be done in 20-30mins with multiple small holes.
I do have all the kit to drill a core hole but it just takes too long in hard brick areas. I'll usually start off a hole with a core drill to get a neat outline then switch to smaller bits.
In softer brick, block or concrete I would just core drill the whole way