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Do Closed Doors Reduce Cooling Costs?

Temperatures are rising and if you use an air conditioner in your home, you may be looking for ways to cut down on cooling costs during these hot summer months. A common theory is that closing doors to rooms that are not being used will reduce the amount of space needed to cool, which will, therefore, improve energy efficiency. Read on to find out if limiting the amount of air movement in your home will actually lower your energy bill.


Many people have the misconception that if they close doors in their home, it will reduce the amount of space that they need to heat or cool. While this sounds good in theory, it is actually a myth. Closing doors and vents in rooms that are not being used can raise your energy consumption. When you close a doorway, you block the path for air to efficiently move throughout your home.

Your home’s heating and cooling system work properly when the amount of air returning back to the furnace or air handler equals the volume delivered through the supply registers in each room. When doors are closed, rooms become pressurized and the air pressure pushes conditioned air through small openings. Rooms with closed doors start to leak air.

The air that escapes is replaced in an equal amount, which can increase the amount of air being drawn from 300 percent to 900 percent, significantly raising energy bills. This replacement air comes through places like the chimney, water heater or furnace flue along with any other small openings. Since the air is not coming through the HVAC system, it is not filtered and therefore contains dirt, dust, and humidity which could affect the air quality in your home.


Now that we have established that closing doors is not energy efficient and can be quite dangerous to your home, you might be wondering what other options there are available to keep your cooling costs down. If you are looking to safely and efficiently cut down on energy costs this summer, there are many effective and reliable options such as:

  • Turning off your cooling system at night and opening your windows while sleeping. In the morning, shutting the windows and blinds to keep the cool air inside
  • Installing window coverings to prevent heat gain through your windows
  • Operating your thermostat efficiently
  • Using a ceiling fan while using an air conditioner, which raises the thermostat setting about 4 degrees with no reduction in comfort
  • Scheduling regular maintenance for your cooling equipment


Bob’s Heating & Air Conditioning installs top-of-the-line water heaters, air conditioners, furnaces and other systems that provide comfort and the highest indoor air quality in Western Washington homes. At Bob’s, you will only find qualified expert technicians dedicated to providing the best service. Additionally, Bob’s Heating & Air Conditioning proudly partners with organizations focused on sustainability and innovation, including Built Green, Energy Star, and Puget Sound Energy.