Evaporative cooler


#1

Is there any way to modify the code for an evaporative cooler? The components that would need to be controlled are the water pump, high speed fan (when setpoint is ~ 5 degrees F above setpoint), and low speed fan (when at or ~ 2 degrees F above setpoint). Can only run one speed at a time. I’m an HVAC tech and very familiar with the wiring aspect but lacking on the programming side. There’s no need for heat control, cooling only.


#2

Welcome to the club @mstudent We are swamped right now with the production of the units sold during our crowdfunding campaign and we cannot help very much atm. What I can say though is that the units available in the next ~45 days will have Heating/Cooling option and 2-stage support which I believe is what you need. Not sure if the 2 thresholds (2 and 5 degrees) will be the same but maybe we can make this a variable from the GUI.
Have you built your HestiaPi yourself?


#3

I’m in process of it right now. We live in New Mexico, in higher elevations (6300’/1920 meters), and it is very dry so traditional A/C does not work well without dehumidifying the air further. I haven’t gone into the code yet, maybe I can gain some insight by looking into it.


#4

Does evaporative cooling run on a different wire? Can it be ran on the same wire as the cooling or does it have a different run cycle? Curious because I don’t live in an area where these humidifiers are typically installed in air handling ducts.

If you do need to run the cooling and humidifier on different wires then I know openhab can be configured to support it if you replace the heating configuration and reuse the gpio pin from the heating but it would require quite a bit of reconfiguring.

I’ve switched over to iothermostat (I didn’t need openhab’s additional features) otherwise I’d offer to help. :slightly_frowning_face:


#5

Thanks for the response. The way evaporative coolers work is by starting a circulating pump which wets the media, then brings on a fan which pushes fresh, humidified air into the house actually cooling it. I have no need for heating control (radiant floor heating) as they are two totally separate systems. Right now I’m using a nest with Y for the pump, and G for the fan. The nest doesn’t pre-wet the media before it brings on the fan, so I end up with a lot of dust in the house until the media is wet, nor does it control the second speed of the fan. What I’d really like is on a call for cooling, to bring on the pump for 2 minutes to pre-wet the media, then however close to setpoint the temperature is, bring on either high or low speed fan. I wish I could work on it more than I’ve been able to, but wife doesn’t like me sitting in front of the computer quite that much.


#6

The hardware version ONE can surely support that. The software needs a minor tweak to use

  • the first stage heating for first stage cooling
  • the second stage heating for second stage cooling
  • add the (variable) 2 minute delay to the fan

Both hardware and software will be available first on the crowdfunding page. The shortly after the software will be released on GitHub.