I installed my humidistat on the wall in my house and was wondering which location is more effecient / effective at reading the humidity level…on the wall or on the return duct at the furnace.
Thank you for your email regarding your model 700M Aprilaire humidifier. When the humidistat is installed in the living area it will control the humidity level based on the conditions in that specific area. If the humidistat is installed on the cold air return the humidistat will control the humidity level based on the humidity coming through the cold air return, This air is a mixture of all the air in your home. The humidistat can be located in either area. The desired location has to do with where you are most concerned with the humidity level.