Air Balancing 101

For most homeowners, your HVAC system is out of sight, out of mind—as long as you’re getting climate-controlled air when you adjust the thermostat, you probably don’t spend much thought on your system’s health.

But poorly balanced ducts can lead to hot or cold spots in your home. This puts extra strain on your HVAC system as it works to keep your home a consistent temperature. Read on to learn more about air balancing, including some signs of an unbalanced system, and what to do to get your home back into balance.

What is Air Balancing?

“Air balancing” is exactly what it sounds like—a way to equalize the air that flows through the registers in your floor, wall, or ceiling. Each of these registers has a duct attached that delivers conditioned air into the room. These ducts are sized so that a specific amount of air can enter each room to keep it comfortable.

But over the years, as HVAC equipment is replaced or your ductwork develops small leaks, this alters the balance of airflow. Your HVAC system may force more air into smaller rooms and less air into larger ones. Not only does this put more strain on your ductwork, it can also force your furnace, air conditioner, or heat pump to work overtime to try to get your home back to a consistent temperature. This problem becomes even worse when your thermostat is located in a hot or cold spot.

How Can You Tell if Your System is Unbalanced?

The key sign of a poorly balanced duct system are hot or cold spots in your house. Sometimes a particular room will need a larger supply duct, additional return air, or both to fix the problem. In other cases, the repair is as simple as adjusting a damper. However, sometimes a complete redesign of your home’s duct system may be necessary to fix even simple-seeming problems.

What Should You Do to Fix an Unbalanced System?

Because it can be tough to assess the cause of a poorly balanced duct system, your best bet is to call a professional as soon as you notice any hot or cold spots. Because repairing ductwork is labor-intensive and can be pricey if you find yourself needing repairs in the heat of the summer, it’s best to have these problems addressed in the cooler seasons if possible.

One important thing to avoid is closing the registers. It can be tempting to close registers in a too-hot or too-cold room to try to balance the temperature in the rest of your home, but every HVAC system is designed to have all ducts open. Closing registers won’t push air to where you want it to go. What’s more, it will exacerbate leaks, cause back pressure on the system, and create condensation at the closed register, which may eventually lead to rusted ductwork.

Some duct systems have dampers—either mechanical or manual—installed on each supply duct to allow you to alter the airflow. Manual dampers can be set to optimize a duct’s airflow, but they aren’t meant to be frequently changed. These dampers are generally located in a home’s attic or crawl space; they cannot (and should not) be accessed often.

Mechanical dampers, on the other hand, are powered and can open and close as they need to. For example, if you have a room that tends to get too hot when the furnace is running, you can install a mechanical damper that closes a certain amount whenever the system is in heat mode. These types of dampers can be very sophisticated and may be a solution to hot and cold spots in your home.

If you’re concerned about your home’s air balance, give the experienced technicians at North East Air Conditioning, Heating & Plumbing a call at (210) 658-1111 or visit our website to set up an appointment. We can inspect your HVAC system and ductwork for any leaks and ensure that each room in your home is getting the right amount of climate-controlled air.


Call: 210-658-0111