Indoor Air Quality | Heating and Air Conditioning

Indoor Air Quality | Heating and Air Conditioning

Indoor Air Quality | Heating and Air Conditioning

Heating and air conditioning systems do more than control room temperature. The HVAC system affects the indoor air quality in the home. Indoor air quality can affect your health.

According to the Environmental Protection Agency (EPA), indoor air often contains a higher concentration of pollution than outdoor air! Adequate ventilation reduces indoor pollutants by diluting emissions from indoor sources, and by carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some air contaminants.

Sources of Indoor Air Quality Problems

The EPA has identified a number of sources of indoor air pollution in homes. These include:

  • Dust, mold and other allergens can spread throughout the home, often through the home’s duct system
  • Dangerous outdoor sources of radon and pesticides can enter your home
  • Combustion sources such as oil, coal, wood and tobacco products produce dangerous carbon monoxide and potentially deadly gases
  • Carpets, linoleum, paint, air fresheners, household cleaning products, pressed wood furniture, cabinetry and other building materials can produce high levels of toxins  


Newer homes are built to be tighter to increase energy efficiency. Consequently, the home may have higher pollutant levels than older homes. When the amount of fresh outdoor air entering a home is inadequate, air contaminants can accumulate to levels that can pose a threat to your health.

Indoor Pollution and Health Effects

General symptoms common to poor indoor air quality include unexplained headaches, dizziness, fatigue, and irritation of the eyes, nose, and throat. Carbon monoxide poisoning can kill in minutes, and is often the result of faulty equipment or ventilation pipes. Other long-term effects from indoor air pollution may include chronic respiratory diseases, heart disease, or even cancer.

Signs that your home may not have adequate ventilation include moisture condensation on windows or walls, a musty odor, dirty heating and air conditioning equipment, and the presence of mold. 

Biological Contaminants

According to the EPA, biological contaminants that affect a home’s air quality include bacteria, molds, mildew, viruses, animal dander, dust mites, cockroaches, pollen, and others. The protein in urine from rodents is a powerful allergen, and once it dries, it can become airborne. Contaminated air handlers in your home’s heating and air conditioning system can incubate mold, mildew, and other sources of biological contaminants and can distribute these contaminants through the home. Professional duct cleaning can prevent this source of pollution.

Controlling a home’s relative humidity minimizes the growth of some biological pollutants. A relative humidity of 30-50 percent is the ideal recommendation for homes. Standing water, saturated materials, or wet surfaces are a breeding ground for mold, mildew, bacteria, and insects. Dust mites are powerful allergens and thrive in damp, warm environments. The repair of leaks and humidity control can assist in preventing these issues.

Indoor Air Quality Solutions

Fortunately, you do have options to ensure that the air quality of your home is pollutant-free.

  • Eliminate individual sources of pollution such as smoking, wood or coal burning stoves. Use natural cleaning products, and remove harmful products.
  • Improve ventilation by opening windows and doors when weather permits. Run bathroom or kitchen exhaust fans, and operate window or attic fans when weather permits.
  • Several add-ons and modifications are available for heating and air conditioning systems that will filter out contaminants and improve air quality. Routine filter changes can assist in keeping indoor air cleaner, and will benefit the heating and air conditioning system by keeping damaging dust out of the system. 
  • Maintaining a clean home will reduce many of the contaminants in a home. Routine dusting, vacuuming, and cleaning prevents mold, reduces dust mites, and dust.

A HEPA filter will remove up to 99% of contaminants from the air moving through the system. If you are not sure if it is safe to use a HEPA filter in your home’s heating and air conditioning equipment, contact your system’s manufacturer, or your Cypress Heating and Air Conditioning technician.


Formaldehyde is a chemical used widely in the manufacture of building materials and numerous household products. It may be present in high concentrations both indoors and outdoors.

Sources of formaldehyde in the home include glues and adhesives, and as a preservative in some paints and coating products. Pressed wood products are a significant source of formaldehyde, and are constructed using adhesives that contain urea-formaldehyde (UF) resins. Pressed wood products include particleboard, hardwood plywood paneling, cabinets, and furniture; medium density fiberboard used in furniture. Medium density fiberboard (MDF) is recognized as being the source of high formaldehyde emissions. 


If your home’s heating or air conditioning system is an older one, your home could benefit with improved energy efficiency and improved air quality with the installation of a new system. Aging heating and air conditioning systems can be breeding grounds for bacteria, allergens and mold. Today’s heating and air conditioning systems typically feature advanced temperature, humidity controls, and filtration systems to maintain ideal conditions and remove airborne pollution.


Some popular solutions for poor indoor air quality include:

  • HEPA Air Purifiers
  • UV Air Purifiers
  • Air Exchangers
  • Humidifiers
  • Dehumidifiers

Contact Cypress Heating and Air Conditioning for additional information. Our certified HVAC technicians will provide a comprehensive in-home evaluation, and determine which type of product will be most beneficial for your home’s indoor air quality.

If you are concerned about the indoor air quality in your home, contact a Cypress Heating and Air Conditioning representative. Our comfort specialists work with you to design a heating and air conditioning solution that can deliver both comfort and optimal air quality. Cypress Heating and Air Conditioning serve Katy, Plano and the surrounding areas, and is a member of the BBB with an A+ rating.