I just purchashed a Modine Hot-dawg garage heater. I cant vent it thru the garage roof or wall my only option is tieing it into the common vent to the house. I have talked to a couple hvac guys and they say it can be done. The common vent is capable of handling the extra btus. The way most of the hvac guys want to connect to the common vent is by taping off it with a wye in the attic and slopeing the connection down to the garage heater. My question is: Has anyone ever had this done or does this sound right? I want to make sure these guys are correct in what they say needs to be done.