?
"harry" wrote

We don't have "furnaces" that need to bring cold air into the house.
It defeats the purpose.


No, it saves energy. You use the cold air for combustion only. You suck it
in, burn it, pass the exhaust gasses out. Meantime, you heat the heat
exchanger and only inside air is recirculated. Why would you want to burn
the air you just paid to heat?

Newer burners are made to connect to outside air. In the case of the OP, he
is going to vent into the room with the burner, a less efficient method. It
saves sucking the heated air from the rest of the house and burning it, but
is not as good a a seal system.