Shading your central air conditioner will not make it run more efficiently. In fact, it could actually cause additional problems.
Heat waves continue to sweep both the US and the world. Heat warnings and advice have been issued at least twice this summer for more than 100 million Americans.
Now many people are looking for the best ways to stay cool without breaking the bank. A VERIFY viewer sent us a question about installing a blind over the central air conditioning unit of a home outdoors.
“It’s been rumored on social media that shading the air conditioner with an umbrella reduces electricity bills and helps it run more efficiently,” Jennifer said in an email. “Is that true?”
Does placing a shade over your outdoor central air conditioner reduce electricity costs and help it run more efficiently?
No, installing a blind over the outdoor unit of your central air conditioner will not reduce electricity bills or make it run more efficiently. However, shading can be effective for a window unit A/C.
WHAT WE FOUND
A blind over the outdoor unit of a central air conditioner cooling an entire house does not noticeably improve energy efficiency. It can even restrict airflow and make air conditioning run less efficiently, experts say.
“It’s not statistically significant,” said Wes Davis, the chief of technical services for Air Conditioning Contractors of America (ACCA). “That’s the short answer.”
Davies pointed to a 1996 study by the Florida Solar Energy Center that found that localized shading over central air conditioning reduced power consumption by a maximum of 3%.
“Our measurements did not allow us to conclusively state that air conditioning condenser shading, when confined to the immediate area around the condenser unit, offers statistically consistent reductions in cooling energy consumption,” the study authors wrote.
Not only is there little benefit in shading the area immediately around the air conditioner, there is a risk that the unit’s performance will degrade. This is because the method of shading, such as a tarp or umbrella, could restrict airflow to the unit.
Air conditioning in a central air system works by first drawing the air from inside your home and sending it to the condenser, which is the box with a fan located outside of your home. Inside this unit, a condenser coil separates the heat from the air, and that heat is then expelled to the outside by the fan at the top of the unit.
Air conditioners are designed so that a certain amount of air flows over the coil and fan, says Energy Vanguard, a company that focuses on building performance training and consulting. Objects placed directly above the device, such as an umbrella or tarp, or plant debris clogging the fan at the top of the device will restrict airflow and trap heat above the device.
“With less air flowing over the coil, less heat is dissipated,” says Energy Vanguard. “That means the whole cycle heats up a bit and your air conditioner works harder to keep your home cool.”‘
RELATED: No, closing doors won’t save money on central air conditioning
But while localized shading can’t do much, it’s not a bad idea to take advantage of more widespread shading for your air conditioning and home alike.
“The preferred strategy might be long-term: locating air conditioning condensers [the outside unit] in an unobstructed location on the shady north side of buildings and dependent on extensive landscaping at the site and neighborhood level to reduce local air temperatures,” the Florida Solar Energy Center study authors said.
While the benefits are minimal, if you have the option to move a unit or install a new one, there’s no harm in placing your air conditioner so that it’s on the shadiest side of your home. Davis said his home is on the east side of his home, so his home shades the air conditioner when the day is at its hottest, as the sun moves east to west throughout the day.
The real benefits come from shading your entire home — that’s what the study meant when it said to “use extensive landscaping at the site and neighborhood level to lower local air temperatures.” The US Department of Energy says that carefully positioned trees, shrubs or vines can save up to 25% of the energy used by a typical home.
“Adding landscaping that increases shade throughout the yard creates a cooler microclimate,” says Direct Energy, an electric utility. “This reduces your home’s cooling load and helps lower the local air temperature for your condenser.”
Window air conditioners work differently.
Their design makes shade less likely to restrict the unit’s airflow, and according to Direct Energy, direct sunlight on a window unit can reduce its efficiency by up to 10%.
RELATED: How to stay cool in a heat wave: 5 quick facts
Want something VERIFIED?
https://www.king5.com/article/news/verify/weather-verify/shading-central-ac-unit-wont-reduce-power-energy-costs-bill/536-e5803a41-cd2f-4bc9-a440-f3fc50fa391b Putting a shade over central A/C unit won’t save money