Gravity Furnace: seal bt concrete floor and furnace
kcthree
| Posted in Energy, Heating & Insulation on
We have a gravity furnace heating our home in San Francisco. I am looking forward to replacing it some day but it wont be this season.
Question: how should the furnace be sealed to the concrete floor of our basement? There is currently a bead (like caulk) of concrete between the floor and the exterior vertical wall of the furnace. The bead of concrete is totally cracked and missing in many sections. Someone reparied with aluminum duct tape in a few spots but thats falling off now too.
Do I need to reseal the joint between the concrete floor and the vertical exterior wall of the furnace? If so what is the prefered method & materials. Some of the gaps are close to 1″.
THanks,
Kent
Replies
Why would you seal the furnace to the concrete floor? Is there underground duct, like maybe the return air? Is the bead you refer to just a means of leveling the surface that the furnace rests on?
All gravity furnaces I have seen are sealed with concrete at the base, it's probably to keep the furnace from drawing return air from the basement floor.
I think the only purpose of sealing would be to keep bugs out. Use whatever works.
I believe they all had no bottom. The heat exchanger sat on the floor, and was wrapped with the sheetmetal. the sides of the sheetmetal were bolted together and the the top was installed. Then the duct openings were installed. When mine was removed, I found a ton of marbles, a 1940's pack of cigarettes, a 10k small gold ring, metal (lead?) soldiers, beads, antique D-cell, bugs, dirt etc on the concrete floor.