Hi, I have a new home near completion. Today I went there and saw the
furnace is up and running. The gas water heater is also installed but water
pipes haven't been connected. The furnace is Payne PG8J, I googled and found
The water heater is 50Gal Ruud Guardian Pacemaker.
Both are sitting on a raised wood platform in the garage side by side.
The furnace has cold air return from the top (duct is in attic and return
opening is at a hallway). The hot air is blown down into ductwork in the
crawl space then to many registers. The furnace has other two ducts: one is
obviously the flue as it is hot. This and the flue from water heater go to a
Y and a thicker one goes through the roof to outside. There is another
relatively large round pipe (about 8") branches from the cold air return
just above the furnace. This one goes through the wall to outside. There are
some wires going out of the pipe at one place and connect to a box of
electronics attached to the wall. I could read some wording on it look like
"fresh air damp.." so I guess the furnace will draw fresh air through this
duct from outside for its combustion oxygen need. It will not use the air in
the garage. But how about the water heater? It doesn't have such duct (just
the flue). Do I need keep garage window open a crack to supply air for it?
By the way, do these Payne and Ruud have a good reputation?