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Comment by ahaucnx | Hacker News Reader

There was quite some work involved because the house was originally very leaky and for this system to work it needs a very good sealed home. So I spent quite some time and money to close the leaks. It probably cost me a few thousand USD to get it to this point but for us it was definitely worth it. Especially because we periodically have extremely high outdoor air pollution.

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How did you find the leaks ?

If there is a thermal difference (cold outside and furnace is running, or hot and AC is running) a cheap thermal camera can find them fairly quickly.

In the US at least, where building codes favor air sealed construction, door blower tests are fairly accessible: https://www.energy.gov/energysaver/blower-door-tests

How did you use the thermal camera exactly? Any tutorials on that?

I have a garage, and I had issues with using the thermal camera - if the building materials were not uniform they reflected/radiated IR unevenly. It could show a piece of uninsulated area as hot and very well insulated as cold.

Get some wash-off spray-on chalk (essentially spraypaint that won't survive the next rain, because it's made to disappear when hit with rain/a hose). That should give you sufficiently uniform surface emmissivity to deal with those problem spots.

Thanks!

Do I do the measurements from the outside then, not the inside? Seems difficult in some cases unless I have a drone (roof, other hard to reach areas).

Do you know if i can find a tutorial anywhere? I tried googling, but couldn't find anything easy to understand.

I use a FLIR One on Android. I've charted internal leaks (where cold air blows in through cracks) and external (where heat escapes through eg old windows). Wait for a cold day (eg 0C), heat the house, investigate everything you can. My 1930s London house has SO many leaks, I've spent 3 years slowly fixing them. I have a talk I should give on using 12 Govee hygrometers to back-calculate moisture (absolute humidity) coherent per room, as I was charting moisture loss to trace air leaks.

Yes we also used thermal cameras for leak detection. Quite effective.

Industry standard in HVAC is to use a door blower to provide positive static pressure and then use a fogger. It works quite well since you have a direct visual indication and are not deriving loss from a secondary observation (temp/humidity).

Does the few thousand include the blowers?

Yes but it was a very customized solution which we also used to test and improve our air quality monitors that we develop.

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