While September can be slightly cooler, it’s often when a/c systems stop working. The relentless heat of July and August takes a toll on a/c equipment new and old. But consumers can hack their a/c bills to save money throughout September and into the cold months ahead.

Heating and cooling are a home’s most expensive systems, typically chewing up 48 percent of the utility budget, according to the U.S. Department of Energy (DOE). And Texas bills are especially big. Dallas has taken first place on Forbes’ list of U.S. cities with the highest energy costs. But there are ways to dull the teeth of an a/c bill’s bite. Here are a few ideas you can pass along to your customers for maximizing a/c efficiency and keeping cool.

Windows

Summer heat constantly assails 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 the 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 the 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 a home’s space and electricity bill. If you aren’t using it, pull the plug.

Ceiling 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 the 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 an oven or stove-top.

A/C Efficiency

What about the a/c unit itself? One of the easiest ways to boost efficiency is to regularly change the filter. If you’re running the a/c 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 a/c fan speed for low.

A Cold House is a Heat Magnet

There’s a weird myth that it’s more efficient to run the a/c all the time rather than turning it off and on. So lots of folks leave their a/c 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 a/c running, heat tries to get in, making the a/c work harder trying to disperse the heat. Instead, turn off the a/c when leaving the house. The home will heat up to a point, then stop. When you come home, turn the a/c back on. The system will do much less total work. And the bill will reflect that.

Annual Checkup

Remind your customers that getting an annual checkup can save on a home’s energy bill. An HVAC professional can spot problems and correct inefficiencies.

Eco A/C

Yes, buying a new central air conditioner isn’t cheap. But modern Energy Star models are much more efficient, leading to energy and cost savings. In fact, it’s possible to cut a home’s a/c cost in half. And qualify for a tax credit. Look for a unit with a high energy efficiency ratio (EER).

Plant for the Future

Make a plan to prepare the home’s exterior for next summer. Planting trees and shrubs outside windows — especially if that’s the location of an a/c unit —- will block those hot rays. Even when you factor in the 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.

Using these a/c hacks your customers should see a significant savings in their energy bills. And that will bring their heat-induced stress level way down.