Humidity Level

[RoyalSon]

I recently had an Alpine Air whole-home dehumidifier installed and connected to my Nest Learning Thermostat (3rd gen.). Everything is operating properly with the exception of one glaring issue, being that the dehumidifier continues to run well beyond the configured humidity level.

Example:

With the desired humidity set to 50% the whole-home dehumidifier engages / turns on if the RH exceeds 50% as expected. However, the whole-home dehumidifier DOES NOT disengage / turn off until the RH reaches 45%. At a rate of 1% per hour, the whole-home dehumidifier is running for no less than 5 hours. This is extremely costly and inefficient. This begs the question, what is the RH tolerance? 5%?

Troubleshooting:

In the example above, if manually toggle off the dehumidifier using the Nest app and toggling back on while the RH is lower than 50%, the whole-home dehumidifier remains off until again hitting 50% RH.

Feedback:

Assuming the RH tolerance is 5%, Google should reduce this to 3% or lower. It could be argued that 1% is most appropriate, but I'll give Google the benefit of the doubt since the tolerate for the RH sensor is +/- 3% as per the Nest Learning Thermostat Pro Installation & Configuration Guide.

Conclusion:

At an estimated 2.5kWh, the resulting consumption is 12.5kWh over the course of 5 hours every time the Nest Learning Thermostat engages the whole-home dehumidifier. This, instead of an estimated 2.5kWh to go from 51% to the desired 50% RH. Again, this is extremely costly and inefficient. This flys directly in the face of Google marketing the Nest Learning Thermostat as the energy saving thermostat. Do better!

[CoolingWizard]

RoyalSon, an Air Conditioner is basically a dehumidifier. When the RH is high the AC running will condense the moisture on the evaporator coil and drain out.  Some HVAC systems can be set up to focus on dehumidification in which case the evaporator coil has a slower movement of air over it to increase the rate of condensation.

A stand alone dehumidifier is basically a small self contained air conditioner in which the exiting.air is ducted back into the HVAC return plenum.  

I would like to know more about your model of dehumidifier. Can you provide me the model number so I can look it up?

Thank you,

Ken, The Cooling Wizard 

[Jhonleanmel]

Hey folks, 

Thanks again for helping here, @CoolingWizard. 
@RoyalSon, I hope you've got the answer you're looking for. If you're still in need of any assistance, feel free to let us know. 

Best,
Mel

[Jake]

Hey there,

I wanted to check in and see if you had any questions from here. Please let me know, as I would be happy to assist, and answer any you may have.

Best regards,
Jake

[EdwardT]

Hi RoyalSon,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.

Thanks,

Edward

[RoyalSon]

Good Afternoon Edward,

I would like confirmation if the observed behavior is expected? Does the Nest Learning Thermostat (3rd Gen.) keep a whole-home dehumidifier running until registering 5% RH below the set humidity level? With mine set to 50%, the whole-home dehumidifier turns on if registering higher than 50% but does not turn off until the registered RH reaches 45%. One would expect it to turn off once getting back down to 50%. Maybe 49%. I know, for example, that the thermostat will heat and cool 1 degree beyond the set temperature. So why isn’t this consistent with a dehumidifier? My feedback and request is to correct the experience to match that of heating and cooling if the thermostat is in fact coded to a 5% RH tolerance.

[EdwardT]

Hi RoyalSon,

Thanks for the response. The Nest thermostat maintains a 6% humidity range of 1% below and 5% above the set humidity level. (Example: If you have the Nest thermostat set to 30% humidity, the thermostat activates the humidifier when the humidity level reaches 29% and deactivates it at 35% humidity).

I understand that having an option to lower the maintenance band would be helpful. Our team is always looking for ways to improve and we'll take this as feedback.

Thanks,

Edward

[RoyalSon]

Please and thank you!

Having the ability dial in the range would be hugely beneficial. For those using a humidifier, one can over humidify not knowing this information. Conversely, those with a dehumidifier like myself end up running equipment longer than expected. Unsure what or if there is an industry standard, understand my Alpine Air has a documented range of 3% when used independent from an external module.

At a minimum this 6% range should be clearly documented. No one over the phone was able to provide an answer. Instead directed me to contact OnTech. Which I did. At a cost! OnTech was also unable to provide a clear answer while at the house for a $50 consultation.

[EdwardT]

Hi RoyalSon,

We hear you. Our team is working hard to deliver the best experience for our users — we'll take this as feedback. Keep your eye on the Google Nest Community page for any updates. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.

Check out this link on how to file feedback.

Thanks,

Edward