Though most energy conservation measures include weather stripping doors and windows, there are often more serious threats of hot, humid outside air coming into our homes. What difference does it make if our homes leak? In our Florida climate, we are fighting to keep our homes at a comfortable temperature. We recommend 78 degrees in the cooling season. It’s great if you can keep your relative humidity at around 50% because 45%-55% relative humidity is the optimal range. The largest portion of our utility cost is air conditioning. Physics teaches that hot air always moves to cooler air, and wet always moves to dry. This means that summertime in Florida has outside air always trying to find a way into your home.
Over the last month, I’ve been in two homes doing energy surveys that both had the air handler for the air conditioner inside a closet. In one case, there was moisture on the floor. I opened the closet and looked up into the ceiling area, but there was no ceiling. It was open right into the attic. The moisture was from the hot humid air coming from the attic, hitting the cold metal air handler and condensing. The attic air was well over 100 degrees dropping freely into a home while the air conditioner fought to keep it cool. The second home had a hole in the closet ceiling. It looked like it may have had a duct coming through at one time. The round hole was 6 and a half inches in diameter, which means that it was about 33 square inches in size. That is like running your air conditioner with a window partially open, but worse because the attic is hotter than outside!
Do your best to seal the ceiling plane for air leaks. You lose more through ceiling penetrations than from around windows and doors!
Scott Ranck is the Conservation Program Coordinator & Energy Specialist for Florida Public Utilities. Feel free to e-mail any energy-related questions or comments to Scott at firstname.lastname@example.org.