While September in Dallas can be slightly cooler, it’s often when AC systems stop working. The relentless heat of July and August takes a tool on AC equipment new and old. Hack your AC bills to save money throughout September and into the cold months ahead.

Heating and cooling are your home’s most expensive systems, typically chewing up 48% of your utility budget, according to the Department of Energy. And Texas bills are especially big. Dallas has won first place on Forbes’ list of US cities with the highest energy costs. But there are ways to dull the teeth of your AC bill’s bite. Here are a few ideas for maximizing AC efficiency and staying cool inside your house.

Windows

Summer heat constantly assails your windows. Slow it down with good window management. Keep windows closed during the day, then open them at night if the outside air is cooler than the temperature in the house. Remember to close them again in the morning before the sun blazes back in. Putting houseplants in front of your sunniest windows will absorb some of that solar energy.

For a higher tech window solution, install solar screens. These mesh-like screens can intercept 70 percent of the sun’s energy, keeping it out of your house. They work especially well on windows that face east or west. Or try window films, metalized, transparent sheets that block heat.

Lights and Electronics 

Turn off lights –especially incandescent bulbs -- and unplug. Most of us live in a sea of electronics, and all that heat adds up both to your space and electricity bill. If you aren’t using it, pull the plug.

Fan Direction

Fans work by dispersing the hot pocket of heat that builds up around your body. And if you’re sweaty, fans speed evaporation. But did you know that if your fan blows in the wrong direction, it can make you even hotter? Make sure your ceiling fan is blowing downwards. If it’s blowing upwards, it will move the warm air near the ceiling back down towards you.

How do you tell down from up? With most fans, if you’re standing underneath and looking up, the blades should move counter-clockwise. The air should hit you forcefully. If you’re still not sure, stop the fan and switch it so it blows in the other direction. The switch is usually between the fan blades and the light on the side of the fan. Unfortunately, the manufacturer seldom labels the switch so you might not have ever noticed it.

Summer Cooking

You probably associate summer with salad, cocktails and sweet tea. But what if you want a bigger meal? Take up microwave cooking. This will generate much less heat than your oven or stove-top.

AC Efficiency

What about your AC unit itself? One of the easiest ways to boost efficiency is to regularly change the filter. If you’re running your AC a lot, you might need to change the filter as often as every three months. Make sure your unit is level so the condensation can drain. And on extra-humid days, set the AC fan speed for low.

A Cold House is a Heat Magnet

There’s a weird myth that it’s more efficient to run your AC all the time rather than turning it off and on. So lots of folks leave their AC on while they’re out of their house, then try not to hyperventilate when they receive the bill.

Truth is, heat is drawn to cold places. So if you leave the AC running, heat tries to get in, making your AC work harder trying to disperse the heat. Instead, turn off the AC when you leave the house. Your home will heat up to a point, then stop. When you come home, flip the AC back on. Your system will do much less total work. And your bill will reflect that.

Annual Checkup

Getting an annual checkup can save on your bill. An HVAC pro like Lex Air Conditioning and Heating can spot any problems and correct expensive inefficiencies.

Eco AC

Yes, buying a new central air conditioner isn’t cheap. But modern Energy Star models are much more efficient, leading to savings on your bill. In fact, you might even cut your AC cost in half. And qualify for a tax credit. Look for a unit with a high energy-efficiency ratio, also known as an EER. Many HVAC providers also offer financing to pay for a new AC system.

Plant for the Future

It’s too hot right now for outside work. But you can make a plan to prepare your exterior for next summer. Planting trees and shrubs outside your windows – especially if that’s the location of an AC unit -- will block those hot rays. Even when you factor in your nursery bill, you’ll still come out ahead. Installing window awnings will also help. And don’t forget the interior. Attic insulation keeps cool air in.

Use these AC hacks and you should see a significant savings in your next bill. And that will bring your heat-induced stress level way down.