i have a lennox slp 98uhl and have added a water to air heat exchanger in the plenum from a outdoor boiler the water temp is 180 i also have a ac coil in the duck work which is above it what should i run my fan speed at my house is 2000 sq feet with high celings 25 feet i have two thermostats one for the outdoor boiler and one for the gas furnance which runs on varaible speeds should the fan for the heat exchanger be on high ?
High is for a/c. Furnace blowers use medium speed.
Your Ac should be set on high and Heat would would me on MED. However, if you have a true variable speed fan you will NOT be able to set the speed.
