New home owner here – I’m working on sealing the furnace ducts that run through our crawlspace. Previous owner used silver duct tape and not the proper mastic or UL approves aluminum tape. Long story short – I realized there are ducts in our crawl that actually blow heated air into the crawlspace. We don’t have AC, just a furnace (located in Pacific Northwest).
Is this normal? None of the ducts have insulation either, that was going to be my next task but now I’m questioning if it needs to be done? No insulation under the flooring or on the concrete slab. (Single story ranch home – approx 1500sq ft with a 3.5 ft tall crawlspace)
Best Answer
I have seen this done in our area to keep the pipes from freezing and the floors from being cold. On the homes that do this they usually plug the foundation vents for the winter. Many years ago electric heat was super cheap so this option was less expensive than insulating everything. Most places have gone back and insulated the floors and pipes then closed off the duct to save on heating cost