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Shutting Off Your Air Conditioning During a Thunderstorm: Fact Or Fiction?

Here in the Midwest, air conditioning is essential to surviving the summer, and even the early months of autumn. In July and August, temperatures routinely climb above 100 degrees, and September is expected to be both hot and rainy. The Greater KC region has already witnessed a number of impressive thunder and lightning storms that have left some without power. If you’re one of these unlucky folks, you might be wondering whether you should shut off your A/C in the middle of a lightning storm to prevent it from being fried by a power surge like you do other electronic devices such as your computer and television.

The good news is that if a rainstorm is not accompanied by thunder and lightning, you can continue to run your air conditioning safely. A professionally installed A/C unit will not incur damage owing to moisture alone, and moreover can keep your home comfortable as humidity levels rise. That being said, it’s a good idea to regularly check your external unit to ensure that it is clear of any debris and draining properly to minimize the risk of flooding. If you do notice standing water in your unit you should turn it off, shut down the power to your electrical panel, and schedule an HVAC inspection before using your unit again.

While it is safe—with a little precaution—to run your A/C unit during a rainstorm, lightning storms are a different story. A single lightning strike can produce as many as five billion joules of energy, which is enough to fry virtually any electronic device. This includes HVAC systems, which contain sensitive electrical circuits that are highly vulnerable to power surges. A single lightning strike can damage any number of A/C components, including the system controls, fuses, wires, capacitor, and compressor. At its worst, lightning damage can require extensive repair or full replacement of an air conditioning unit.

While they aren’t 100% foolproof, there are some ways to protect your A/C unit against power surges during a storm. Despite their name, surge protectors do not offer sufficient protection against lightning strikes; by contrast, installing a protection system can mitigate the possibility of frying your unit. Conductors, lightning rods, and ground rods all offer lightning an alternative path to travel from the sky to the ground, diverting it away from your in-home electrical system. If turning your system off entirely during a lightning storm is not an option for you, consider investing in a lightning protection system.

Of course, the only surefire way to avoid electrical damage during a storm is to power down your A/C unit at the first sign of lightning. And this is easy to do! A/C refrigerant is nonflammable—which means you don’t have to worry about surprise “fireworks”—and you don’t even need to disconnect anything. Simply adjust your thermostat to ensure that the system is not running (which is the only time your air conditioning unit is vulnerable to damage), and wait for the storm to blow over.

September is one of our stormiest months, which means it’s the ideal time to invest in A/C maintenance and ensure that your unit is up to the task–come rain or shine. Moreover, if you suspect that your A/C unit has been damaged, call us right away to schedule service with one of our technicians.

The experienced professionals at Cates Heating and Cooling provide heating and cooling services to residences and businesses in the Greater Kansas City area. For Kansas City air conditioning service and repair, or to obtain a free estimate on new air conditioning installation, contact Cates today. We can help ensure your system is in tip-top shape so that you stay comfortable even when the weather is anything but!

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