The goal of this project is to have a wifi connection with a relay to open the fresh air intake to my HVAC system. The HVAC part is already installed and I am manually flipping the switch. It has a place to connect a remote switch and I know it works shorting the terminal with a wire.

The two time I want it to open are when my thermostat measures low humidity in the house winter time when heat or fireplace are on. Secondly with a current draw sensor on my range hood after some much run time at each speed. When one or both of these conditions are met the relay is closed and the damper opens to let new air in.

The box in the furnace room will have power from the furnace/air handler.

I have seen the Shelly units are there others that maybe better long term?