3 Types of Ventilation Processes You Need to Know

You may not think much about ventilation in your Berlin, Maryland, home. However, signs of poor ventilation can appear as condensation on windows or walls, stuffy air, dirty HVAC vents, and biological growth in damp, moist areas. Find out how outside air enters and exits your home through infiltration, natural ventilation, and mechanical ventilation.


Cracks in walls, gaps in windowsills, and openings around door jambs are all sources for outside air infiltration into your home. Compared to older homes, newer homes tend to be insulated well and sealed to prevent outside air infiltration. Without air exchange, however, these homes can allow harmful particulates to build up indoors.

Natural Ventilation

Natural air exchange occurs when outdoor air enters through open doors and windows. You feel this type of air exchange with air currents generated by wind and temperature differences between the indoors and outdoors.

Mechanical Air Exchange

Mechanical air exchange takes place when devices such as exhaust fans move and vent air to the outdoors from a single room. For example, ventilation exhaust fans are commonly used in bathrooms and kitchens. Additionally, fans and duct work in a home can remove stale indoor air and provide filtered outdoor air to the rooms of your home.

Why Is Ventilation Important for Optimal Indoor Air Quality?

Home ventilation levels are measured by an air exchange rate, the rate at which outdoor air replaces indoor air. ASHRAE, formerly called the American Society of Heating, Refrigerating and Air Conditioning Engineers, recommends that "homes receive 0.35 air changes per hour but not less than 15 cubic feet of air per minute (cfm) per person." When a lack of air exchange takes place, indoor air pollutants can accumulate, potentially causing health problems for people with asthma and allergies.

By increasing ventilation to promote fresh air exchange, you can lower pollutant concentrations and create a healthy indoor environment.

At Custom Mechanical, we understand the importance of making your home’s indoor air as healthy as possible. Contact our indoor air quality experts at 877-696-0808 for information about indoor air quality testing, air purifiers, and air cleaners.

Image provided by Shutterstock

Compliance Settings
Increase Font Size
Simplified Font
Underline Links
Highlight Links