Modern Americans take their heating and cooling systems for granted. We've grown accustomed to our carefully adjusted interior temperatures; cool in the depths of summer, and warm while winter winds howl outside. In fact, you easily could go a whole year without cracking your windows.

But that could be a costly mistake: If you've put off having your heating, ventilating, and air conditioning (or HVAC) system serviced and have kept your home sealed for too long, that likely means your home has built up indoor air pollution.

Keeping up indoor air quality (or IAQ) is a constant struggle. Many of our daily routines introduce contaminants to the air. Smoking is one  source of indoor pollution, as is an improperly maintained HVAC system. Other sources include mold from the bathroom and elsewhere, environmentally unfriendly household cleaners, air purifiers that put out ozone, air filters that go unchanged too long, and unvacuumed floors and furniture, which house pet dander and other contaminants. The health risks from any one of these factors can be substantial; when combined, they can add up to a serious health danger.

This infographic, compiled by Malek Services, summarizes the best information available on improving your home's indoor air quality. It offers helpful tips for things you can start doing today to fix the problem. Of course, nothing can replace regular maintenance of your HVAC system by a qualified professional. However, your efforts can't begin and end with calling in a service professional. Take the initiative in cleaning your air, and you'll find your quality of life improving as well.