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Closing Vents and Doors to Unused Rooms

By: Danny Lipford

Open HVAC heating cooling vent on ceiling.

You might think that closing the vents and doors to unused rooms in your house would be a good way to lower your heating and cooling bills; but it can actually cause problems for the HVAC system in your home, since central heating and cooling systems are sized to accommodate a specific amount of square footage.

If you reduce the amount of square footage the system heats and cools, it will cause your furnace or air conditioner to cycle on and off more frequently. This results in additional wear and tear on the unit, and makes it harder for the HVAC system to regulate the humidity level in your house.

So your best bet is to leave the heating/cooling vents open in all the rooms of your house, and keep the doors open as well. If doors to rooms need to be closed, make sure there’s 1/2″ or larger gap between the door and floor to allow air to circulating freely throughout your home.

Watch this video to find out more.

Further Information

Video Transcript

Danny Lipford: Vincent has this question, “Will I save money by closing off the vents in unused rooms, and closing the doors to those rooms?”

You know, you would think if you closed off a few rooms around your house, and shut down all of the air conditioning and heating going into those rooms, you’d actually save money on your energy bill. Well, that’s a myth, and here’s why.

A modern central air conditioning and heating system is designed and sized for a certain amount of square footage. If you turn down and shut off some of that square footage, it’ll still heat and cool; but it’ll do it in a much different fashion, because it’s what they call short-cycling.

It’ll turn on, turn off, turn on, and it will provide a lot more wear and tear on your system, and it’s not going to last as long. And at the end of the day, you’re actually going to be spending just as much or more on your energy bill.

So, it’s better to leave the doors open, and make sure you’re not turning off any air conditioning and heating vents, anywhere in your home.


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4 Comments on “Closing Vents and Doors to Unused Rooms”

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  • Official Comment:

    Thomas Boni Says:
    May 28th, 2019 at 2:58 pm

    Hi, Bill,
    Generally, we don’t recommend this. Closing the vent just builds pressure in the ducts, which causes all kinds of issues.
    The most efficient approach is to install zoned heating and cooling.
    Good luck!

  • Bill Says:
    May 24th, 2019 at 9:38 pm

    My Florida house bedrooms all have both a closable incoming air conditioning vent and a separate return vent. To save a llittle on energy bills in the summer, may I close off one of these unused bedrooms without causing damage to my a/c system?

  • Andy Says:
    July 31st, 2017 at 11:50 pm

    I have to close most of the vents in the basement of my split-level in the summer or the downstairs will be very cold and the upstairs will be hotter. I reopen the closed vents in the winter to keep the downstairs as warm as possible. I can’t afford a two zone system. I’ve done a lot of research to see a better alternative for little cost and what I’m doing is cheaper. I have four returns upstairs, closing two downstairs vents works as well as possible. The builder who built the house years ago before we owned it put in a barely adequate system and cut corners. Make do with what we have.

  • Cheryl Says:
    July 31st, 2017 at 8:35 pm

    My question is; when it’s hot here I Pennsylvania my central air runs nonstop until around 10-11:00. Do I need to have 2 air conditioners?

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Closing Vents and Doors to Unused Rooms