Fact Check: Will shading an AC unit with a canopy lower energy bills?
This summer is another testimony to how much we have tampered with the Earth's thermostat. The United States, United Kingdom, and many other parts of the world have experienced unprecedented excessive heat waves. Life hacks to tame the heat and make living conditions bearable spread like wildfire. One of them was placing an umbrella or canopy over outdoor AC units. Users on social media claimed that people could lower their energy bills and the temperature in their homes.
Is this true?
Turns out, the claims are false. According to the U.S. Department of Energy (DOE), shading the AC unit with an umbrella or canopy is pretty much pointless. A spokesperson for the DOE told Snopes, "This is a myth. Shading an AC with an umbrella would have a negligible effect."
Funnily, this isn't the first time the supposed claim has come about. Rather, it resurfaces every summer. Back in 2017, the Direct Energy blog took a look into the issue and noted a few logical flaws with the shade solution.
"First, there’s an assumption that the sun shining directly onto the unit causes the whole thing to heat up like a brick. Now, shading the condenser might reduce the sun’s heat on the casing but the condenser’s casing doesn’t conduct that much heat to the internal fins and tubing. In fact, all those bits are already under shade inside the case," Direct Energy writes.
Studies have been undertaken to prove the issue 'false.' In 2010, researchers from the Kuwait Institute for Scientific Research studied the impact shade had on air conditioners and revealed that shading alone would only result in a maximum of increased efficiency of one percent. The study concluded: "The actual increase in efficiency due to shading is not expected to exceed a maximum of one percent. Actual daily and seasonal savings in energy will be even lower. The findings of this study suggest that shading alone, without evapo-transpiration, is not an effective measure to improve A/C efficiency or reduce electrical demand."
The actual increase in efficiency due to shading is not expected to exceed a maximum of one percent.
Fret not. There are plenty of tips that work to help cool off homes.
Cool for the summer
The DOE suggests ensuring AC units are clean, such that nothing restricts airflow. People can plant trees around their homes to provide natural cooling to their homes and AC units. The DOE spokesperson said, "Trees or other large structures could potentially reduce AC loads if they can reduce the temperature around the AC units, but trees also have the advantage that shading can also reduce the overall AC load for a building too. Cleaning outdoor units or clearing anything that could restrict airflow would actually make a bigger difference."
Richard Trethewey, a heating and air-conditioning contractor who appears on the television program "This Old House," told the New York Times that proper insulation is key to keeping your house cool and dry in hot climates.
The DOE also asks people to switch the fans off when they're not home as "fans cool people, not rooms." It also suggests running clothes dryers and dishwashers during cooler hours and avoiding using your oven on hot days.
As for lowering the big spikes in your summer electric bills, ask about "level" billing. According to the Edison Institute, raising your thermostat even by just one degree in summer could decrease your electric bill by two percent.