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Why Closing Room Vents Isn’t “Zone Control”

room-ventOne of the services that we’re proud to offer our customers when it comes to air conditioning in Wake Forest, NC is installing zone control systems. With zone controls, you can manipulate temperature levels in different areas of your house separate from one another. There are plenty of benefits to this, such as providing individual comfort for people in your household (no more wrangling over the thermostat when people don’t agree on temperature) and reducing your energy bills by only cooling parts of the home that need it (helpful if you have a guest room).

However, when people hear about the basics of zone controls—dampers inside the ducts shutting off airflow to specific vents—they sometimes wonder why can’t they just do zone control by closing the shutters over the room vents.

There are two good reasons why they can’t: 1) It doesn’t work. 2) It can damage the HVAC system. Let’s take a closer look.

Closing vents doesn’t serve as zone control or provide its benefits

A  simple explanation of zone control doesn’t get into the details about how it functions as a system. Dampers close off sections of the ducts, but a central control panel monitors the dampers and the AC (or heater in the winter) to balance airflow. This system ensures the air conditioner works less when there are fewer dampers open. If you simply close off a vent in a room, the air conditioner won’t put in any less work. The same amount of cooled air is still trying to reach the room, and you won’t end up saving money.

Also, the shutters over a vent simply aren’t a strong enough seal. These shutters are designed to direct the air as it comes into a space, not close the vent off. There will still be some cool air reaching the room, no matter what.

Closing vents can damage the HVAC system

A zone control system is designed to maintain equal air pressure throughout the ventilation system by opening and closing ducts in succession and controlling when the blower fan runs. Closing off vents manually, however, causes the air pressure to spike. The rest of the system doesn’t know the vent is closed, it keeps working like normal. Increased air pressure causes numerous problems. It will lead to air leaks in the ducts. It will cause the blower motor to short cycle, wasting power. It can create icing along the coil. You never want to shut off vents to your rooms for any reason! (In fact, we recommend making a check of your house at the start of each summer to make sure none of the vents have been blocked.)

You’ve convinced me—now how do I get zone controls?

If you’re planning to have a new HVAC system installed in your house, it’s simple to make zoning part of it. Just tell our installers you want zone controls, and they’ll design a system that will work ideally for you. You’ll choose how many zones you want: it can be as few as two (upstairs and downstairs) or as many as there are supply vents. We can also install zone controls as a retro-fit for an existing system, although it may require making a number of changes to the current HVAC configuration. Feel free to call us to learn more.

Serving the Triangle Area of North Carolina: Comfort Master Heating & Air Conditioning, Inc. Comfort, from Our Family to Yours!

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