Why Closing Rooms to Save Energy Can Be Opening Yourself to Trouble

Why Closing Rooms to Save Energy Can Be Opening Yourself to Trouble

Nov 19, 2013

Have you gotten into the habit of closing rooms to conserve energy during the winter? If so, that’s a habit you should break. A recent study by Berkeley Lab found that closing registers and blocking off rooms may actually cause your heating system to use more energy than if it was heating the entire house. While this may seem counter-intuitive, the science behind it is quite sound.

Today’s high-efficiency furnaces are designed to work with the entire heating load of your home in mind. The air handlers and ductwork are calibrated to deliver heat and cooling to that size space. When you close off a room, it reduces the cubic footage that the air handler has to condition. On the surface that seems like a good thing. Unfortunately, when you close the door and the supply vents in a room, the return air vent is not closed. The air handler pulls air into the system from the room, which becomes depressurized. The result is unconditioned outside air being drawn into the room, and then into the ductwork system, through minute cracks and gaps.

Another problem arising from closing rooms to conserve energy involves duct leaks. The HVAC system is designed to produce a certain amount of heated air for your home. This hot air has to go somewhere, and it does. When you close supply vents to a room, the conditioned airflow will force open duct connections and create leaks at weak joints. The heated air will leak out into the cavities between the walls and under the floors. You aren’t actually reducing the amount of heat produced at all; it’s just going someplace where you can’t use it.

In addition, closing rooms to conserve energy can damage your furnace system. According to the Berkeley Lab study, closing more than 60 percent of your vents can seriously damage high-efficiency systems.

At Rinaldi’s Energy Solutions, we can help you find alternative solutions for energy savings. Contact us to learn about zoned heating and cooling systems and variable speed air handlers. We have been finding new ways to save money for customers in Central Florida since 1969.

Our goal is to help educate our customers in Orlando, Florida and surrounding areas about energy and home comfort issues (specific to HVAC systems).  For more information about saving energy and other HVAC topics, download our free Home Comfort Resource guide.

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