If you live in a two story home with a garage, the chances are, you have a bonus room. When I use the term "bonus room" I am referring to a room over the garage that usually has small attic spaces off one or both sides and has a slanted ceiling that run parallel to the roof. These rooms provides the perfect extra space for an entertainment room, office or extra bedroom; that is, until summer comes. From my experience as an energy specialist and having conducted many energy audits, I have heard home owners over and over again complain about the comfort of their bonus room. "It's cold in the winter and unbearably hot in the summer" they usually say. When ever I hear this complaint I can't help but smile because this problem baffles most hv/ac and comfort specialist but to me, a student of building science, the causes are clear. During the energy audit, I continue my fact finding hunt, looking at every aspect of their bonus room to confirm my suspicions and gain deeper insights into the right solutions for their unique situation. In almost every case the causes of the uncomfortable bonus room are the same.
- Attic Air Currents: Insulation performs at its maximum when it is sealed on all six sides. In a bonus room application, usually the wall, ceiling, or floor insulation is only covered on five sides. This exposed insulation is subject to attic air currents which allow heat to penetrate the porous insulation seeping all the way to the drywall. Once that heat reaches the drywall the temperature of the room starts to rise and the hv/ac system can’t keep up.
- Attic Heat Buildup: Unlike other rooms in your house, your bonus room has both walls and ceiling area that is subject to the heat of your attic. As sun bakes down on your shingles it passes through your roof decking and rapidly heats up the attic. That heat then surrounds your bonus room and begins raising the temperature until you can't stand it any longer and leave the room.
- Attic Access Doors: In most bonus rooms there will be atleast two and up to four attic access doors. These doors present two problems. First, they are usually not insulated at all. And second, they are usually not well sealed and allow air to leak form the house to the attic.
- Heat Rises: The final nail on the coffin is the very fact that heat rises. Bonus rooms are usually on the second or even third floor of your home and get all the heat that comes from downstairs