Can I Run My A/C During A Lightning Storm?


Here in Birmingham, Alabama, thunderstorms are just a normal part of life. They’re par for the course during most of the year, but March, April, and May tend to be the peak of our severe weather season. With thunderstorms also comes heat and humidity, especially right before the storm hits. It may be tempting to turn on your air conditioner to help keep your house comfortable, but we have some bad news for you…

You shouldn’t run your air conditioner during a thunderstorm. And if you can hear thunder, you are at risk of a lightning strike.

We hate to be the bearers of bad news, but running your air conditioner during a thunderstorm puts your system at risk. Sure, the chances of your home being hit by lightning are slim, but consider this – a lightning strike could send five billion (yes, that’s with a ‘b’) joules of energy shooting through your home’s electrical system before your breakers trip. What does that mean? Well, long story short, it means a big problem for electric devices in your home, including your HVAC system.

A jolt of electricity that large is way more than a normal surge protector can handle. Damage from a large electrical surge can be very severe, including damage to the internal electrical circuits in your air conditioning, as well as damage to the controls of your entire system. The repairs from this type of damage are not inexpensive. If the damage is severe enough, there may be no way to repair the damage, which means a new air conditioner. When a storm is approaching, you need to ask yourself which is preferable: no air conditioning for a short time, or paying for a brand new air conditioner? Again, the risk that something will happen is slim, but if it does, the results could take a bite out of your wallet.

If you live in an area that is especially prone to lightning strikes, consider having a lightning protection system installed. A lightning protection system includes a series of lightning rods that pass electricity from a lightning strike through the rods and down into the ground. Not only will this protect your HVAC system, it will help to protect all of the electronics and phone lines in your home.

That said, it is perfectly ok to let your system run during a rainstorm, even if the rain is heavy. Just make sure that your outdoor unit is clear of debris and has proper drainage. Flooding can also cause costly problems, if the area around your outdoor unit isn’t properly maintained.