Nest Thermostat Variable Speed Fan

Variable speed fans high voltage forced air systems with fans and proprietary systems with fans aren t compatible with either the nest learning thermostat or the nest thermostat e.

Nest thermostat variable speed fan.

When you give up your nest or ecobee in exchange for the thermostat that comes with your new variable speed hvac system you re still going to have a smart thermostat. The google nest thermostat e is only compatible with single speed system fans. I was told by my hvac maintenance personnel that using the nest thermostat won t allow the variable speed fans to function properly causing inefficiency in the system. Variable speed fans high voltage forced air systems with fans and proprietary systems with fans aren t compatible with either the nest learning thermostat or the nest thermostat e.

The variable speed fan part is controlled by the board so for my single stage cool the program i have chosen dictates the fan ramp and compressor calls. I have my two stage controlled by the nest. An hvac tech may be able to set it higher but then that would be the fan speed all the time. The nest thermostat e is only compatible with single speed system fans.

So far i think it s a good product. The stages can be controlled by the nest thermostat or by the lennox board. With the comfortlink 1050 or 850 thermostat you get pretty much all of the features your existing smart thermostat has. I installed the nest thermostat this past thursday.

I have the same setup as shown in cb242 s first set of pictures for his downstairs configuration using the tcont803as32daa thermostat. With a smart thermostat it will turn the furnace on or off based on temperature. It s the first thermostat i ve ever used that i actually like. It can also use multistages i think up to 3 with nest to turn it to high med low i think.

I m looking to buy a new furnace mine is old and past its life but really like using the nest thermostat. However i am running into issues with the variable speed fan on our high efficiency furnace. Maybe i m not fully aware of how variable speed works. I would like to be able to control as much of the new furnace s features with the.

But with variable speed correct me if i m wrong but the fan is constantly modulating faster or slower. It looks like nest recently added support for multi speed fan control for some furnaces. Nest can t control different fan speeds so if you have a multi speed fan it will always be on the lowest setting.