topic Re: Humidification in Nest Thermostats

Humidification

JerryR2 — Fri, 10 Feb 2023 14:48:34 GMT

I have a problem with how the Nest thermostat works. Can somebody enlighten me? Humidifier is supposed to be on only with furnace heat. This nest device will turn on the fan even after heat is off. This isn’t normal. It should only call for humidity if the heat is also called for.

secondly: If you set a humidity level, it won’t turn off at that level. It wants to overshoot by 5% before turning off and that’s just plain weird to me.
Will they ever fix this via firmware update?

Re: Humidification

Markjosephp — Wed, 15 Feb 2023 16:17:54 GMT

Hello JerryR2,

Thank you for taking the time to let us know about your inquiry. I'd love to know more about this.

A few questions: is your humidifier a stand-alone or integrated into your system? What type of Nest Thermostat do you have? Also, who installed your thermostat with a humidifier?

I'll look forward to your response.

Regards,

Mark

Re: Humidification

JerryR2 — Wed, 15 Feb 2023 16:59:55 GMT

Thanks for responding. I was beginning to think no one at google cares how this nest device works with a humidifier.

Attached are pics of how it’s installed. And what’s installed. Natural gas furnace.

The humidifier is a simple furnace mounted unit. It is designed to run ONLY when furnace is producing heat. This is how all normal humidifiers are supposed to work in upper Northern climate.

Three things really:

1) Why does nest sent the humidify command when heat is NOT on.

2) WHY if I set humidity to 35% it will not turn off until 40%? (5% past any setting I try).

So you can see why the darned thing sends the humidify command basically all the time. Never turns off that signal. Because of what appears to be a purposeful overshoot of 5% combined with a humidity “ON” command without any heat. This makes it impossible to function independently. I always have to use my app to reduce humidity setting so it turns off.

I would think a simple firmware update will fix the problem. Humidifier “ON” signal must meet 2 conditions. The humidity threshold setting of course, plus heat command must also be ON. (Not to be confused with your heat Mode setting)

ID ALSO LOVE IT IF THAT HUGE OVERSHOOT IS DROPPED TO MAYBE 1 or 2% max.

Third item is really a wish list. Since it’s a little computer, can’t a small routine be coded to make this device adjust humidity level automatically based on outdoor temperature? It’s connected to internet so it knows outdoor temp all the time. That would be really cool and make it something user can enable or disable if they want. See chart. (Prevents window condensation and damaging frost forming in winter months). This is cool but not important item for the short term.

Thanks I really hope I don’t have to reinstall that ugly humidity sensor/controller again. 2 installations I have in 2 homes. I’m crossing my fingers!!

Jerry

Re: Humidification

JerryR2 — Thu, 16 Feb 2023 18:09:21 GMT

Sorry to waste your time. I figured it out. There is a setting pretty deep to to trigger on heat + hum.
Good stuff.

cheers!!

Re: Humidification

Markjosephp — Thu, 16 Feb 2023 22:39:15 GMT

Hi JerryR2,

Thanks for keeping me in the loop. I'm glad to hear you've sorted it out. It looks like we can consider this one complete, so I will lock the thread within 24 hours unless I can help out with anything else.

Regards,

Mark