It's a simple system. I have a water to air heat exchanger, basically a car radiator, mounted on the top of my forced air furnace inside the plenum. 8" above the heat exchanger is a fan/limit switch mounted in the plenum. When the house thermostat calls for heat it simply turns on the stoker and circulator pump which pumps hot water through the heat exchanger. After a minute or so the plenum heats up and the fan switch turns on the forced air fan. The fan shuts down when the plenum cools off to 90 degrees, which is a few minutes after the stoker shuts down. My house stays within 2 degrees of the thermostat setting so it seems to be working OK. It looks like this: (I don't know this seller) ebay item #150210360007 There are 2 advantages to doing it this way, one is the cost. My house already had forced air so all I needed was about 20 feet of pipe and I was done. second is I can add a bypass humidifier to the ductwork and have whole house humidity fairly easily and fully automatic. I'm going to buy one in April when they go on clearance. I have 2 large filters in my furnace which takes care of any dust. The furnace can also be used as backup if I ever run out of coal, it is on standby 24/7, it has a separate thermostat set to 55 degrees.