Learn the science of homes- the invisible dynamics of physics, chemistry, and microbiology at work around us indoors every day. Corbett and Grace Lunsford create the TV series 'Home Diagnosis' and scientific home improvement and construction testing videos for homeowners and home performance professionals alike. See the diagnostic tools and building performance testing used to improve home performance, comfort, air quality, durability, and energy efficiency. Watch energy audits, infrared thermography, blower door testing, HVAC diagnostics, and awesome and weird things from our field work as home performance experts. PROOF IS POSSIBLE. STOP GUESSING.
Hey Sir, interesting stuff. I have Panasonic Nanoe X air conditioning at home. I only use the cooling in the summer. I've never used the Nanoe X particle spreader. Is the Nanoe X the same as what your are talking about? Should I be worried to use the air cooling alone? Can't find much info about it, almost all video's on Nanoe X are from Panasonic them selfs. If you read this, can u give me a little advice?
Watching one of the channels I watch about narrow boats... I spotted an interesting thing they are using over there. They have a very small HRV unit for those boats. Not sure if there is an ERV version but It is interesting for RV use etc. I was looking at a cheap import HRV (I know) to install out in my shop to help keep the shop air cleaner than it is. A big unit would actually work great for the amount of gunk in there but they are pricey units. It would be nice to exchange air without loosing so much cool air when it's 110* here. Right now I have a 6" fan that I use to add ventilation when making a mess. Better than nothing but not enough.
Thanks for putting this together. I am planning a gut rehab of an 18-unit multi-family tenement building in NYC. Each unit is only about 400-500 sqft. I plan to replace the central gas boiler with individual unit heat pump, rip out the wall and add close-cell insulation, and replace the windows. Do you think this will get to the 2 ACH threshold you mentioned in other video for the need for ERV? Do Broan or Renewaire still make small ERV suitable for small spaces? Which model would you choose if you have to replace your tinylab ERV now? thanks
With 8 feet walls, that's 4000 cubic feet, so 60 CFM would get 1 ACH. The other question is what do you do for cooking smoke, and associated makeup air? The other issue is getting the ERV vents far enough apart both on the inside and outside of each unit. I'm thinking a consultation with Corbett might be your best bet. It would be cheaper than a mistake you have to fix later.
What do you think of Linear slot diffuser performance. They do look stylish but not sure about their performance. I can see there could be a little bit or air restrictions from the way it looks.
I enjoy your technical assessment and opinions regarding efficient home building and maintenance. I do have a question regarding ERV‘s in general. I will be building an ICF home of about 1500 ft.² for my wife and I and will be trying to achieve a very tight home in the process. I’m looking for your opinion regarding which brand of ERV system you would recommend. There are so many to choose from and the reviews are all over the place as to which one would be the best for my application. Being in maintenance all my life my focus as you can imagine would be the ease of maintaining secondly would be the cost of ownership. I know the initial cost upfront for a good quality unit is not cheap which I do understand. Your opinion would be greatly appreciated.
By the way, SF6 is *super-bad* for the climate. Its Global Warming Potential over a 100-year period is 22,800 times as bad as CO2, molecule by molecule. Google's AI calls SF6 "the most potent greenhouse gas known." Its use in home testing needs to be scaled back to zero.
Good point, but it's creating an electric field, not a magnetic field. I could get into the details, but this is the simple nitpicky comment ;-) Love your channel!
When I see someone using a probe rod, I lose attention to anything they have to say. HPT meter, dig down to get a 10 ft reading and if soils are bad there, helical to 25 kps and call it a day.
Since the high limit hole will give you a HIGHER reading than actual, I doubt many techs are either testing there or reporting the reading they get when they do. Every 0.01” counts.
So...yet another annoying note for the gullible.... Its easy to find 'independent labs' who will conjure up any report you desire if paid enough... but an easier route is just to blatantly lie and or fabricate a test report as long as you leave the car right out back with the engine running...
Having designed such units and others for NASA from 1985 to 1990...I learned there are a large number of gullible people in the world who lack critical thinking skills. Another note...at 400° it depends on the rate of air flow and how long the pathogen of concern, wether microbial or viral is subjected to such a temperature....Some pathogens may be 'killed' and others simply deactivated. Some pathogens will be biological and some will be chemical... Even when a biological pathogen is killed or deactivated it may still have the capability to reactivate, simply mutate or spontaneously regenerate. Chemical pathogens are often unaffected. Therefore is is prudent to not only kill and deactivate but to also physically remove the pathogen. in whatever state of existance. Because you can still be easily afflicted by a pathogen which is generally regarded as being 'dead'
Hi Corbett, it's my understanding that those pleated filters that are "carbon infused" simply don't contain enough carbon mass to effectively eliminate chemicals for any sort of extended time. Do you have any research or data contrasting pleated carbon filters to something that contains larger carbon pellets in a thicker kind of honeycomb structure? Or more broadly, is there any sort of certification for carbon filter effectiveness?
Ok. UV light is bad. Check. Be most fearful of the unknown unknowns. Check. But did he say that improved ventilation prevents the formation of larger particles and that the smaller particles that remain present a greater risk because they diffuse deeper into the lung tissue. Game over, man. Game over.
I’ve done this service on my indoor head 4-5 times now, with your instructional video. But there’s something missing. What about the bank of coils in the back that faces the wall. How do you clean them effectively with the limited space due to the ceiling. Been using Viper coil cleaner but hasn’t effectively cleaned all the coils, this time around.
Years ago I had a talk with an HVAC designer. He said he went into a commercial building and the exhaust fans didn’t work. So he asked the project manager about it, the guy said don’t worry about it. So he called the building inspector. They said nothing we can do about it. So he asked what does that mean? The response the inspector said we went rounds with him til we were blue in the face and there is nothing we can do. The code book says every bathroom has to have an exhaust fan, but no where does it say it has to work. So this contractor buys broken ones from a salvage yard and installs them to save money. So when you say the exhaust doesn’t work, by code it doesn’t have to.
Hahahaha oh my god nooooo. One more reason code doesn’t work. FYI there may be a ventilation standard like ASHRAE rmbedded within the applicable code, which would need to be separately referenced. That would do the trick in some cases, but it’s a battle of wills sometimes.
It's a cool product but wouldn't a wood buck extension (say 2.5 inches of ripped 2x4) plus the 2x6 stud behind it (the wall jacks) already have an R value of close to 11? Even a triple pane window is around R8. I suppose there's still a three R gain for a couple square feet of wall per window. I'd want to run the numbers first, I suppose. Definitely an interesting product.
Great system. I have created almost the same system with a few key differences. First my exhaust fan is a remote fan located in the attic exiting through the roof. I used a Linx silencer right before the fan and it works very well, especially since I have a 1,300 cfm system. My make up air is where things really differ. I ran a duct line under the house out the foundation using a square to round adapter on one of the crawlspace vents. A Belimo actuated damper controls the trunk line when the fan is in use. This crawlspace line then ties into the return on my HVAC system. When the exhaust is in use the damper opens and I wired a signal into the thermostat to hijack the HVAC fan. The fact the return line is connected to both the outside duct line and the regular house return allows the system to self balance pressure wise with no noticeable difference. The benefit to this design is that I use the existing HVAC to condition the outside air in both hot and cold conditions. The other benefit is the “brains” cost. I control all of this with a $25 dual relay and 120v to 24v doorbell transformer. All said, well done. Not enough people understand the benefits of indoor air quality and the need for makeup air.
So I need to know, if I use a water based air washing system in my home instead of fibrous filters to remove both particulate pollutants like pollen, cat hair, and dead skin particles, and also water soluble air pollutants like VOCs, will that remove NOx pollution as well? And if I then use a dehumidifier to bring the washed air back down to target humidity, and a 254nm UV sanitiser (with the whole system inside an opaque case to protect us from the UV) to make sure legionella doesn't breed on the dehumidifier, will that work and give my family safe air to breathe - without ozone, without legionella, and without all the pollutants commonly present in untreated air both indoors and out?
@@shubinternet That's why the 254nm and not shorter. It can give you cancer if you expose your skin to it, but it doesn't create ozone. So if you put it in a case where your skin will not be exposed to it, all it's going to do is kill any legionella or other pathogens that get in the way of its light, without having any consequences outside the case.
It's great if you have a space in your home or office that will not cool off. Otherwise just get a fan but i think there is a place for this because not all of us can afford to rework our ac system.
Going back to chemistry... you can't create or destroy, so the true formula is NO + O³ -> NO² + O² (they are missing the oxygen in the output). Also, one of the top causes of death is overdosing on di-hydrogen oxide. 😀
I feel like I need the cliff notes of these cliff notes. Any takeaways I missed? -ERV is better than HRV chemically speaking -It’s hard to notice ineffective vent fans. Check them
Love it!! Thanks for your interpretation on the science talk to technicians talk. 👍 Like a translator. A government exhaust fan broken! No way!! In shocked 😅
This is essentially the preferred method shown in the install manual with exception to the 6ft separation. Check it out if you don't believe me. Page 10, figure 11.
Great video!!! Just to make sure I got it… NIST is saying there’s no evidence of water-soluble VOCs being redirected back into the house by an ERV? Did I understand that correctly?
ASHRAE241 is critical to be implemented- we’ve been ignoring airborne pathogens for over 100 years, even though we knew how to solve it. To ignore this is the equivalent of continuing to poop in the well. The primary mechanisms in 241 are ventilation and filtration and in combination that should reduce at least the particulate impact of supplemental UV in the specific circumstances where it makes sense. Curious about the impacts of carbon sorbent filtration on Nox and O3, I know it works well, in sufficient quantities, on VOC concentrations, but I don’t have O3/Nox sensors yet to test.
You don’t want to add a chemical reactor (like UV exposure)to filtering and processing your water or air. You have no idea what happens when the UV light is exposed to the substance you’re filtering or processing.
With a move to higher-end filtration, does it make sense to add an axial flow fan in situations where the pressure drop on the return side becomes a challenge for an existing system?
Who knows what chemicals are in these industrial no rinse cleaning spray? For all I know it can have phthalates or other harmful chemicals that you’ll be breathing in when your mini split blows this stuff out.
@8:02 A smart man would have just taken the angle bracket off the wall and simply notched it so the track would just continue down under the shelf.. but that's just me.. cabinet builder for over 23years...
What about for people who don't have A/C, like practically every home in the UK? The temperature has been unbearable for me these last few days so I just ordered a couple of similar Homedics devices to put on my desk (I work from home) and beside my bed. I'm hoping they will be more effective than just a simple desk fan which just blows warm air at you anyway...
