Month: June 2021

I learned something new today that I thought I’d share in case it might help someone here. This applies specifically if you have a Nest thermostat, but if you have a smart thermostat of another brand it may be worth looking into to see if you are having a similar issue.

I moved into a house recently that had been completely remodeled, including a new HVAC system and newly installed Nest smart thermostat. I was surprised how humid it felt inside the home, given that the remodel seemed really well done and I couldn’t find any significant gaps in the doors or windows. I would run the A/C to cool the house down and the humidity would temporarily drop a little bit but then climb again after the A/C shut off. I bought a little electronic hygrometer and it was showing consistently in the upper 50% range and most days it even got above 60%. I wrote it off as just a quirk of living in an older home and bought a big dehumidifier. While the dehumidifier helped somewhat, it still felt stuffy and more humid inside than I was used to. The Nest was giving a lower humidity value that seemed more normal, but the dehumidifier and hygrometer were higher and more in line with each other. So I didn’t really trust the Nest reading to be honest.

Today I learned that Nest has a feature built into it that was likely making it worse. The feature is called Airwave and it’s supposed to increase efficiency and cooling by running the fan for a few minutes even after the compressor shuts off, ostensibly to continue cycling cool air. However, running the fan without the compressor can sometimes blow condensation from the A/C coils back into the house (sorry if I’m using wrong terms, not an HVAC expert here). Here’s a much better explanation than I could ever hope to provide: https://youtu.be/_pQ443d-NsE?t=307

Anyway I turned the Airwave feature off earlier today and I already feel a huge difference. I normally kept my AC at 70 or 71 during the day because I was hoping that keeping it cooler would pull the humidity out but it never really seemed to work. After turning off the Airwave feature I upped my thermostat to 74 and it feels infinitely better in the house. My little sensor thingy is currently reading 52% instead of 60%+, and my dehumidifier isn’t running (thank god because the noise was slowly driving me insane).

TL;DR: if your house feels too humid and you have a Nest, try disabling Airwave. If you have another brand of smart thermostat, see if there’s a feature where the fan keeps running for a few minutes even after the compressor shuts off. If so, try disabling that feature and see if the humidity goes down.