Can't stand the heat? Some home air conditioners stay cooler under pressure

When it's hot, though, and the AC goes out, we call a repairman, desperate for a fix.

“There’s nothing worse than turning your air conditioner on and then finding, ‘Oh, no, my AC’s not working,' and then we get that panicked phone call and we have to run out,” said repairman William Strempski.

The keys to having your air conditioner there when you need it: Get the right system, and take care of it.

Consumer Reports surveyed more than 16,000 subscribers to find out which brands you can count on.

For conventional systems, American Standard is more reliable than other brands, while Amanas are more likely to break. Consumer Reports estimates about 30 percent are likely to break within five years.

“A lot of things can affect how well a system works: how it’s installed, the quality of the duct work, even the size and layout of a house," said Consumer Reports' Home Editor Dan DiClerico. "But choosing a more dependable brand can boost your chances of getting a system that lasts.”

The responsibility is on you, too.

Even the most reliable air-conditioning system will let you down if you don’t maintain it.

Check and clean filters monthly. Clear debris and leaves from around the condenser coils, and check for blockages in the drainpipe.

Also, look over insulation around ducts. Increasing it or fixing leaks can help prevent as much as a 40 percent energy loss.

And once a year, bring in a licensed professional to check things like refrigerant and mechanical components.