Insulation is a crucial part of maintaining a comfortable temperature in your home. Homeowners tend to think about it more in the winter, when it helps keep your rooms warm on a chilly day, but insulation also works to keep cooled air inside during the summer.

Many homes aren't insulated as well as they could be, though. Angie Hicks, founder of the home service comparison company Angie's List, says stricter building requirements regarding insulation didn't come about until the 1970s, so older homes are less likely to be adequately insulated. Even newer homes might have insufficient insulation in certain areas, such as crawlspaces or attics.

Any missing or inadequate insulation will result in more air-conditioned or heated air escaping your home, which in turn results in higher energy bills. Tracking down and addressing these weak spots will not only save you money, but make your home considerably more comfortable.

Ideally, insulation should be located in multiple places within the home. The Department of Energy says these include the space between the attic and living spaces, exterior walls, and floors above cold areas like crawlspaces and unheated garages.

A home energy audit is an excellent way to pinpoint any inefficiencies in your home. This process includes a blower door test to find out where exterior air is entering as well as a thermal scan to see cooler spots where insulation is missing. The thermal imaging company FLIR Systems Inc. says this process is most effective if done on a day when there is at least a 20-degree difference between the outside temperature and the temperature inside the home.

Most homes have insulation in the attic, but this may not be enough to keep warm air in the home. Green Energy Solutions Inc., a company in Hillsboro, Ore., says the insulation may be too thin to prevent heat loss. Older insulation will also settle and flatten, providing less of a barrier against heat loss. The Department of Energy recommends adding more insulation if the attic insulation has an R-value less than R-30.

Even if you have adequate insulation in the attic, it may be missing at the edges of the roof. These gaps can be particularly harmful during the winter, since they leave cold spots where the roof meets the exterior walls. When rising heat melts snow and ice on the top of your roof, the runoff will refreeze on these cold areas and form ice dams, which prevent water from properly draining off the roof and can lead to water intrusion in the home.

Crawlspaces can be either ventilated or unventilated, and it is more effective to insulate the foundation walls of an unventilated crawlspace. However, you'll also want to periodically check this insulation to make sure it hasn't been damaged by water or pests.

Wall insulation may become less reliable over time. Hicks says insulation can fall down if it comes loose from the studs, leaving uninsulated areas higher on the wall. Blown-in insulation will also settle over time, resulting in cooler areas where the wall meets the ceiling.

Electrical outlets provide an easy way to check for insulation in the walls. The Department of Energy says you'll need to turn off the power to the outlet, remove the outlet cover, and use a flashlight to look into the walls. This will let you see if any insulation is present and what kind of insulation it is.

Don't assume that all of your walls are insulated just because you find some at the first outlet you check. Take a look at other outlets throughout the wall as well.

The outlets themselves can also be a major source of heat loss, along with switches. Green Energy Solutions Inc. says outlets and switches are often installed with no insulation around the electrical box, creating a gap in the insulation where air can escape. Adding insulation to these gaps, or using special outlet covers, can be very effective.