7 Ways to Save Money on Your AC (Without Breaking a Sweat)

An air conditioning unit with the words "money-saving AC tips."

I wrote an article last year in which I discussed weatherproofing options for keeping cool without air conditioning. The truth is, it's just as important to similarly weatherproof your home even if you do have air conditioning.

Air conditioners, especially older ones, are among the biggest utility bill offenders. Making them and your home more efficient not only helps to keep you cooler, but also saves money. Whether you have a window unit or your home is centrally air conditioned, there are things you can do around the house to make your home more energy-efficient, minimizing the use of air conditioning and lowering your bill.

1. Ensure Proper Installation

If you have a window or in-wall unit, make sure that it's installed correctly and well sealed so that hot air does not come in and cool air is not lost from around the perimeter of the unit. Window units are easy to install and remove during cool months. In-wall units are larger and often left in place for winter, but can be removed and the hole in the wall sealed for the off-season in extremely cold areas.

2. Give Your Unit Regular Maintenance

The simplest thing to do to make your HVAC unit more efficient, and to therefore save money, is to regularly replace the filters. Most units are manufactured with disposable air filters that should be changed about once a month. Even if your unit is working well, central units should be cleaned and checked by a heating and air conditioning specialist once a year to maximize continued efficiency.

3. Ditch the Old Thermostat

adjusting thermostat

Central air conditioning units are typically controlled by a strategically placed thermostat mounted on a wall. Replace an old thermostat with a digital version that's programmable—some for up to a week or more. They can be programmed to reduce operation when you’re asleep or when aren't home and come back on in anticipation of you waking up or returning. Some are even Wi-Fi enabled, allowing you to control them from your smartphone or computer.

While a bit pricey compared to the standard version, digital thermostats are generally easy to install by reconnecting the existing wires. However, sometimes there is complicated wiring and less experienced do-it-yourselfers may need to seek professional help.

4. Consider Energy Efficient Lighting

Outlets, light switches, and light bulbs can be a source of heat. Energy efficient lighting not only cuts down on electrical consumption, but generates significantly less heat in the room, requiring you to run the AC less.

5. Install Weather Stripping

Weather stripping is designed to stop the flow of air around doors and through window sashes and frames when they're closed. Simple products make for easy do-it-yourself projects—latex caulking can be used to seal leaking window frames. I always recommend using a high-quality latex caulking; it will last longer and is paint-able, so you can match it to the color of your window frame.

As for doors, there are products you can purchase that are designed to seal doors to their frames. They're simply screwed in place around the perimeter (three sides) of the door and attached with screws. Weather stripping attached to the bottom of a door is called a “door shoe,” and seals the closed door to the threshold. Door shoes are made of aluminum with a rubber gasket on the bottom, which seals them to the threshold. Installing the door shoe is a straightforward project, as it slips on and is just screwed in place. However, sizing the shoe may involve a bit more skill, requiring cutting the metal shoe to length. In addition, the door may have to be cut shorter to accommodate the height of the shoe, which will require removing the door. One needs to have a table and saw to cut it and reseal the raw edge on the bottom of the door before installing the shoe and re-hanging the door.

6. Install Window Film

sun shining through window

One could also put energy efficient film on all windows, which dramatically reduces heat transfer. These easy-to-install films can be cut to fit the glass and attach by static-cling.

Some manufacturers claim the films can reduce up to 70% of the sun’s heat, which will in turn reduce your summer cooling costs dramatically. While claims are made by manufacturers that the film allows natural light to enter, they do make the room darker. They also alter the architectural appearance of the glass. That is, from the outside windows appear to be mirrors during the day.

7. Insulate with Rubber Window Gaskets

Windows are among the greatest culprits for allowing heat and cold transfer. The ideal way to insulate is to replace old windows with new, energy-efficient windows. However, this is not an inexpensive project and should only be tackled by an experienced do-it-yourselfer or a professional. One of the easier, more economical ways to insulate windows is to use rubber gaskets. The simplest is a rolled insulating material with an adhesive backing, which is applied by pressing it around the window.