Does your air conditioner usually do a decent job keeping your home cool but seem to become overburdened during a heat wave? Since this is when you need your AC the most, it's important to get to the bottom of the issue and address it. Here's a look at some common reasons why AC units fail to keep up on the hottest days -- and how you can address each one.
Clogged Air Filter
It may be that all you have to do is run down to the basement and replace your air filter. When the air filter becomes clogged with dirt, your AC unit has to use more energy to push air through it. As a result, the unit may be overheating and turning off before it has a chance to completely cool your home.
If you have pets in the home, using a HEPA filter will catch more of the pet dander and hair. Otherwise, a basic fiberglass or cotton filter is really all you need. These only cost a few dollars -- maybe less if you buy them in bulk! Going forward, make sure you change your filter monthly to avoid this issue.
The problem could be that there is an obstruction in one of your ducts. The obstruction would keep the cool air from reaching certain rooms. Even if it's just a partial blockage, it may impede air flow enough to reduce cooling capacity on the hottest days.
You may be able to detect a blockage by placing your hand in front of the AC vents in various rooms. If air flow to one or several vents is lower, this could indicate that the duct leading to the vent is blocked. Your HVAC company can use special equipment to reach down into the duct and remove the blockage -- which could be anything from a dog toy to a birdsnest.
The problem might be that your home is not well insulated. Heat is leeching into the home faster than the AC unit can remove it. There are many sources of poor insulation:
- Gaps around the windows, allowing air to flow in.
- A lack of insulation in the attic or between the walls.
- Old, single-pane windows that allow for a lot of radiant heat transfer.
If your windows are old or loose, having them replaced may be the best way to encourage better cooling on the hottest days. If your attic is low on insulation, dedicate an afternoon to unrolling an extra layer on top of the existing one. For walls that lack insulation, call an insulation contractor to blow loose-fill insulation or spray foam between the walls. (Some HVAC companies also offer this service.)
Some of the cooled air could be leaking out from gaps between the ducts before it even makes it to the vents. A mild earthquake or even vibrations from dropping something heavy on the floor can jar a duct loose -- especially an aging duct -- creating a leaky gasp. This causes similar symptoms to a blocked vent: lack of air flow. Your HVAC contractor can determine whether a leak or blockage is to blame when they inspect your system.
Leaky vents are pretty easy for your HVAC contractor to fix. They can work the loose vent back into place and secure it either with duct tape or some welding.
If your home is not cooling off well on the hottest days, this is surely a sign that something is amiss with your AC unit or the related systems. Contact your HVAC contractor or a company like Smedley & Associates to help get to the bottom of the issue so you can enjoy a cool, comfortable home.