Should I Close Vents in Unused Rooms?

When you’re searching for ways to save energy at home, one common tip you might come across is to close the supply vents in rooms that you don’t use very often. Although this might seem like a good idea at first, the truth is that closing off supply vents can lead to many negative consequences, including actually raising your monthly utility bills. Today we’re going to address this common misconception by answering the question, “Should I close vents in unused rooms?”

Why closing vents in unused rooms seems like a good idea

In theory, closing vents in unused rooms seems like a good idea. By closing off the vents in a room, you’d expect that cool air would skip that room and be delivered to the spaces that need it instead. As a result, your air conditioner would be able to focus its energy on only cooling rooms that you occupy, which would decrease the amount of work it would have to do. But is that really what happens?

What actually happens when you close vents in unused rooms?

The truth is that closing off the vents in unused rooms can lead to some unintended consequences. You see, air conditioners are designed to deliver a specific amount of air based on your home’s size and specifications. Supply and return vents are strategically placed so that the amount of air that comes out of your supply vents is equal to the amount of air that is sucked in by your return vents. If you close off the vents in a room, you throw off the intended pressure balance that your system is designed to operate under, which can lead to the effects below.

The side effects of closing vents in unused rooms

• Your energy bills will be higher. When you close off supply vents, air will build up inside of your ducts because there will be less vents available to release that air. This can raise your energy bills for a couple of different reasons. For one, the increased pressure in your ducts will make it harder for your air handler to blow air into the ducts, and the restricted airflow will cause efficiency problems similar to a dirty air filter. In addition, if your ducts have leaks, the increased pressure in your ducts will push air out of those leaks and force your system to work longer to compensate.
• Your system can break down. Restricting airflow to your system by closing off vents can cause your air handler to overheat and your evaporator coils to freeze over. In addition, because your system has to work harder when pressure builds up inside your ducts, closing vents in unused rooms increases the chances of overstressing major components like the compressor and causing those parts to break down.
• Your home can encounter comfort issues. When you close off the supply vents in a room, the return vents in that room will attempt to suck in air from wherever it can get it. Often times this means pulling in outside air through leaks in your walls, floors and ceilings which can make your home uncomfortable.

If you have any questions about closing vents in unused rooms, or if you’d like a cooling system serviced or installed in your home, contact Hydes, your Indio, CA, air conditioning contractor.