Do you have a traditional furnace? If so you may be able to set up a series of dampers to open a bypass around the main duct and blow air over the miner and then back into the supply when heat is called for and when no heat is needed lose the dampers and run the miner and exhaust the heat elsewhere, garage, attic, outside. Then you could setup the miner to be your stage 1 heat with stage 2 bring your current furnace heat source.