What You Should Know about Air Exchange Rate

What You Should Know about Air Exchange Rate

What You Should Know about Air Exchange RateIf you’re like many homeowners, you may not be familiar with the term “air exchange rate.” However, the rate of air exchange in your HVAC system is one of the key factors in how well it heats and cools, and its ability to maintain a healthy, comfortable indoor environment.

Air Exchange Rate Defined

An “air exchange rate” refers the number of times per hour that air is replaced in each room of your home. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommended air changes per hour vary according to a room’s use: a bedroom requires five to six exchanges, while a kitchen should have seven or eight.


To determine the necessary cubic feet per minute (CFM) of airflow to provide adequate air exchange in specific rooms, an HVAC pro multiplies the room’s volume (height × width × length) by the recommended number of changes, then divides that figure by 60.

The Importance of Sufficient Air Exchange

Today’s homes are constructed and weatherized to limit energy losses and boost efficiency. With our extended cooling seasons, homes here are also closed up for long periods to keep conditioned air inside. When a home lacks adequate air exchange, allergens and pollutants will build up inside too, resulting in air quality issues that can impact the health and well-being of the occupants.


If you have an older home that isn’t as tightly constructed or sealed, leaks in the exterior envelope may allow some fresh air to enter. If the amount isn’t sufficient, or you have a tightly-built, well-sealed home, your HVAC contractor may recommend taking extra measures to maintain good indoor air quality, like:

  • Integrating an air cleaner into the HVAC system to remove pollutants and allergens from the air supply.
  • Adding a ventilation unit to expel stale air and introduce fresher outdoor air.
  • Keeping your HVAC, air cleaning and ventilation equipment well maintained, and replacing the filters regularly to ensure they’re working effectively.

To schedule an HVAC system assessment to determine if the air exchange rate is sufficient in your Peachtree City home, contact us today at Powers Heating & Air.


Our goal is to help educate our customers in Peachtree City, Georgia and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 770-487-2040. 

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