10 Must-Know Tips for Your Air Conditioner

During the summer, air conditioning can cause really high electric bills, and I would hate to think that you might be spending more money on electricity than you have to. If you have central air conditioning, here are 10 ways that you can take care of your air conditioner to keep it running efficiently, which will save you money. (These tips are written with the non-mechanic in mind, so you can do them.)

1. Change your air filter every 3 months. Changing the air filter is as important for your air conditioner as changing the oil is for your car. Put in a new filter at the start of summer, and then at least once every 3 months after that. If you live where it is windy or there is construction, or if you have allergies, you might need to change it more often.

When you replace the air filter, there’s an arrow on the side that indicates which direction to place the air filter. The arrow shows the way the air flows through the filter into the unit.

2. Buy pleated filters. Spend a couple of dollars more to buy pleated synthetic filters, not the cheapest fiberglass filters. To get a good filter for a good price, Doug recommends the True Blue pleated air filters at Home Depot with a Filter Performance Rating (FPR) of 5. (He thinks the filters he saw at Lowe’s are overpriced.)

3. Check to see if your air conditioner is cooling efficiently. You can measure if your air conditioner is working the way it’s supposed to by comparing the temperature of the air blowing out of the vent to the temperature of the air going back into the return air vent. There should be 15 to 18 degrees (F) difference between the two temperatures. A higher difference might indicate an issue such as a clogged air filter. A lower difference could mean a problem like your AC is low on Freon. Either way, it’s using a lot of extra electricity when it’s not running efficiently, and it’s time for maintenance.

4. Set your thermostat at a normal temperature. Don’t turn your thermostat all the way down. That won’t help your house cool down faster; it will just make your AC work longer.

5. Protect your ducts. If you’re doing home renovations and knocking down walls like we did, tape temporary air filters over the return air vents on the wall. This will prevent dust from getting into your ductwork. (The filters in the photo above are the cheap fiberglass air filters, not the kind you should buy for your unit, but they were fine for this.)

6. Check your ductwork for leaks. You don’t want all the cold air to leak out into your attic, so check to see if you notice any holes where air escapes. There are two common types of ductwork: flexible ducts and rigid metal ducts. Flexible ductwork is often used because it’s faster to install, but it doesn’t last as long. Metal ductwork lasts longer. If you have holes or leaks in your flexible duct, it’s time to replace it. If you have a leak in metal ductwork, you can seal it with…can you guess? Duct tape. (Yes, that is why it’s called duct tape.)

7. Insulate your ductwork. Ducts usually run through the attic, and it gets hot up there. It’s worth investing money in an extra wrap of insulation around the ducts. Get the insulation wrap that is backed with foil, not plastic, because the plastic breaks down over time.

8. Clean your outside unit annually. Dirt and debris build up on your outside unit (the condenser), which blocks airflow and makes your air conditioner work harder. Once a year you want to wash off the debris; first turn off the power, and then you can use a garden hose. Gently rinse it so the water cleans between the thin metal fins on the condenser. (You don’t want to spray against the fins because they can bend easily.)

9. Secure your outside unit. Your outside unit is a target for theft. It’s not that they want the air conditioner itself, but the copper inside is valuable and can be sold as scrap metal. Keep your unit out of view with hedges or a fence that will also provide shade for high efficiency, but take care not to block the airflow. You can also bolt it down to the concrete base.

10. Collect free water. Air conditioners create a lot of condensate from the air, and that water drips out of your house from the condensate line. During the summer months, our air conditioner puts out over five gallons of clean water from the air every day. Set a water barrel on the side of your house under the condensate line to catch the drips, and use that to water your landscape.