I have a Packaged Terminal Air Conditioner (PTAC) system in my home that is nothing short of terrible.
I’ve attempted to install smart Thermostats to it in the past, but scrapped everything because of one main issue. The wiring for the PTAC has both high and low fan speeds. After extensive research, I was not able to find a compatible smart thermostat that allowed for two fan-speed wires. Instructions from the PTAC manufacturer said to use either the high speed or low speed fan wire for the G slot in the thermostat.
I don’t really want that. I want to be able to control the fan speed, which is really useful for quick temperature changes and when we have a lot of people over.
My idea is to use a zwave relay/swich of sorts that has two inputs for both fan speed wires and one output which will be connected to the thermostat. Is this possible? Has anyone ever done this before? I don’t know where to start, what relay/switch to get or even how to properly search for this.
I apologize if I’m not using the correct terms and any help would be greatly appreciated!