Should You Close HVAC Vents in Unused Rooms?

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The myth behind closing your vents

You may have heard that closing vents in unused rooms will lower your energy bill. Unfortunately, this is a common myth. Closing HVAC circulation to certain rooms may result in issues with your ducts. It creates a less efficient heating and cooling system and can be dangerous. Ultimately, closing vents in your home isn’t a good strategy for saving on energy costs. Read on to learn why and what you can do instead.

Does closing vents in unused rooms save energy?

The short answer is no; closing your vents does not save energy. When you close vents in unused rooms, your central air conditioning and heating system will push the excess air to other places in your home and build pressure within your ducts. In fact, closing vents may even waste more energy than operating your system as usual.

What happens when you close air vents in your home?

Your HVAC system is compatible with your home’s size and layout. If you close any vents, you are throwing off this delicate balance, which makes the system work overtime to heat or cool the rest of your home. Over time, increased air pressure can cause problems in your home.

Static pressure in your air vents

Static pressure is the resistance to airflow in your HVAC system. These systems are designed to have the right balance of static pressure. Closing vents will increase the pressure, which can restrict or stop efficient airflow in your home.

Problems that result from static pressure in your air vents

Closing air vents can lead to several different issues in your home:

• It can cause leaks in the HVAC system or make existing leaks worse.
• It can make your HVAC system less efficient rather than saving energy.
• Pressure can damage your heat exchanger, resulting in dangerous carbon monoxide leaks.
• Inefficient or misdirected heating and cooling may result in mold growth.
• Leaky ducts can lead to elevated radon levels, a leading cause of lung cancer.

What to do instead of closing vents

We recommend keeping vents and interior doors open as much as possible for the best airflow. If comfort is an issue, try closing certain vents partially. Closing vents no more than 75% of the way can ensure that air keeps circulating throughout your home so the pressure is even and your energy bills stay as low as possible.

Regardless of how many vents you have open, the heater or air conditioner produces the same amount of air. The added pressure from closing a vent can cause several problems in your HVAC system and, ultimately, waste energy. So, does closing your vents save energy? Our experts say no — it does not save energy, and you are better off keeping vents open.