Many homeowners are not aware of the basic way their HVAC system works. Among the various common mistakes homeowners make when running their HVAC systems is creating a pressure imbalance by closing interior doors while the system is running.
It’s a common belief that by closing doors to unused rooms and shutting off dampers homeowners can save money on utilities by not heating or cooling the room. It seems to make sense, but unfortunately, it doesn’t work that way. Closing interior doors will result in uneven heating and cooling throughout the home, and can even put a strain on the unit so that it does not work efficiently. Here’s why.
HVAC Systems for the Whole House
HVAC systems are designed to heat or cool an entire house — not just a room, like a window unit. Although there are likely supply vents in most rooms of the house to distribute cool or warm air to the occupants, there are usually fewer return vents to take air into the system for cooling or heating. When a room is blocked off, and it doesn’t have both a return and supply vent, the intake or proper distribution of the conditioned air can be impeded.
What’s more, closing an interior door while the HVAC is on will trap the air that has been distributed to that room. This increases the pressure in the room, forcing conditioned air out of small openings or cracks around the room — in walls, around windows, in the ceiling or floor. This pushes the conditioned air into an unconditioned space, wasting energy.
Closing an interior door while the A/C is not cooling will starve a room of air, as it’s closed off from the home’s airflow. Negative pressure occurs, allowing unconditioned air to seep in from those same cracks mentioned above. Air quality will be worsened, and the system will be unbalanced.
It’s best, if you need privacy, to just keep the door opened a crack to maintain balanced air pressure.
For more on HVAC issues, contact Arpi’s Industries. We serve Calgary and the surrounding area.
Our goal is to help educate our customers in Calgary, Alberta about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide.