Air Sealing Tips for Hot Humid Climates

By Carl Seville, Networx

Since we’re heading into the summer, and it may well be a hot one this year, it’s a good time to look at home improvements that can help save energy and make your house more comfortable in those hot, sticky months coming up. Air conditioning installers in Miami and other hot, humid climates are going to get a lot of work this summer. How can you get the most from your investment in air conditioning?

The first thing that homeowners and contractors need to understand is that air sealing is really important. The most common insulation, fiberglass, doesn’t work very well when air leaks through it. It’s actually a pretty good filter for dirt (you may have noticed that it’s used for those cheap furnace filters), when you cut open an old insulated wall you usually see big streaks of dirt where air has been blowing through the insulation for years. Not only do air leaks keep the insulation from working, they let lots of humid air into the house, making your air conditioner work harder. Tightening up those leaks keeps the house more comfortable, keeps the humidity lower, and saves a lot of energy in the process.

So where do we need to air seal, you might ask? Pretty much everywhere, but let’s start at the bottom. For now, I’ll assume that you have a wood framed floor with a vented crawlspace below it, and probably fiberglass batt insulation installed between the floor joists. Carefully pull out the batts around any big holes like tub drains, pipes, big wires, and any other place where there are holes in the floor decking. Plug those holes with foam boards, spray foam, or anything else that won’t let air pass through. Don’t jam fiberglass insulation in the holes – it won’t air seal anything. Then carefully caulk all the small holes where wires and pipes pass through the floor.

Finally, make sure that all the insulation is pushed up tight against the subfloor and held in place with skinny metal bars called tiger teeth. If you’re really ambitious you could seal and insulate your crawlspace, but that’s a little too involved for this post.