- Closing air vents to save money actually damages central AC systems by creating pressure imbalances that strain equipment and increase electricity bills over time.
- The practice of blocking vents worsened existing ductwork leaks, causing up to 30% of cooled air to escape into walls and crawl spaces instead of cooling living areas.
- Experts recommended better cost-saving alternatives including clearing vent blockages, changing filters regularly, and installing smart thermostats with room sensors for efficient zone control.
If your home has central cooling and your first electric bills of the summer are higher than expected, you might be looking for ways to cut costs. Closing air vents in rarely used parts of the house sounds like a good idea, but it will end up costing you more in the long run, and in more ways than one.
While most of us think of a house as a collection of parts (walls, roof, plumbing, furnace, etc.), it’s actually a system in which all these components have to work together. The equipment that distributes cool air throughout the home during the summer (and heated air come winter) is one of the more delicate parts of this system.
That’s because your central AC is designed to maintain balanced airflow throughout the entire house. When you close the vent in part of the house, that balance gets out of whack, putting strain on the blower and motor. That, in turn, leads to higher electricity bills as well as a greater risk of pricey repairs and premature equipment failure.
But wait, there’s more! The increased static pressure will also exacerbate leaky ductwork in your home, resulting in more loss of conditioned air. In fact, the U.S. Environmental Protection Agency reports that up to 30% of the air that moves through a home’s duct system escapes through leaks and holes, in effect cooling and heating crawl spaces, wall cavities, and other places where ducts run.
Better ways to slash cooling costs
While closing vents is a bad idea, these steps will help cut cooling costs this summer.
- Check for blockages. Start by locating all the vents in your home. They will be covered by a grate, called a register, that regulates the flow of conditioned air into the room. Registers can be located in floors, walls, or ceilings. After ensuring that they’re in the open position, make sure they're not blocked by furniture, curtains, or anything else that could impede airflow.
- Change the filter. Doing this a few times throughout the cooling season will keep your central AC system running smoothly and efficiently. Central AC filters usually sit behind the main intake vent, often with a dedicated slot built into the air handler.
- Consider a zoned thermostat. If you live in a big house, chances are you have zoned heating and cooling. In that case, it’s worth installing a smart thermostat with satellite room sensors that will maintain different temperatures based on occupancy. Our experts like the ecobee Smart Thermostat Premium, which also includes a built-in air quality monitor, so you’ll be alerted to high levels of carbon dioxide, airborne chemicals, and other pollutants.
Having written thousands of product reviews and how-to articles on all aspects of home ownership, from routine maintenance to major renovations, Dan (he/him) brings more than 20 years of industry experience to his role as the director of the Home Improvement & Outdoor Lab at the Good Housekeeping Institute. A one-time roofer and a serial remodeler, Dan can often be found keeping house at his restored Brooklyn brownstone, where he lives with his wife and kids.
