Should I Keep My Ducted AC Vents Open Or Closed?

If you’re lucky enough to have a ducted air conditioner in your home, you’ll be familiar with its excellent benefits. They cool quickly, are super quiet, and tucked away in the ceiling, preserving the beauty of your home.

But they aren’t without their downsides. They can be expensive to run, especially if you’re cooling a large area. That’s why some people manually close the vents in areas that aren’t being used—but is this effective? Should ducted AC vents be opened or closed?

Let’s find out.

Ducted AC vent open or closed?

Your ducted AC vents should always be open, so that the system’s airflow works as intended. It may seem like you would save electricity by closing vents in areas that aren’t being used, but all this does is increase air pressure in the ducts, which can eventually cause them to burst. A bursted air duct is not only expensive to fix, but can also drastically increase your AC’s energy usage because air is constantly escaping from the system.

Closed vents also play havoc with the system’s ability to regulate the temperature. A ducted air conditioner is a finely tuned piece of machinery that is constantly measuring the temperature and adjusting air flow to maintain it. When you manually block vents, this regulation is hindered and might cause the system to work harder than it needs to, wearing out its parts more quickly, and leading to more frequent repairs or replacements. Most importantly, the lack of airflow may cause the system’s evaporator coils to freeze, which can eventually destroy its compressor. Compressors are rarely cost-effective to replace, so you’re looking at an entirely new system. Finally, because closing your ducted AC vents will make the system less effective, you’ll probably end up being uncomfortable and sweaty!

If your ducted air conditioner uses a zoning system that allows you to activate or deactivate cooling for certain areas, you already have an inbuilt and energy efficient way to “close” vents, so you definitely shouldn’t need to close them manually.

Which way should ac vents face?

AC vents should face in a direction that allows cool air to be expelled as close to the ceiling as possible. When this happens, the cool air is able to displace warm air before it sinks to the ground, which helps to achieve faster and more efficient cooling.

When vents are faced down towards the floor, it’s much harder for the cool air to displace the warm air above it, because cool air sinks, and warm air rises. This results in slower cooling, less effective cooling, and higher energy bills.

So if your vents are in the ceiling, angle them sideways while leaving enough of a gap for ample air to flow through. And if they’re on the wall, point them upwards towards the ceiling.


Ducted air conditioners are designed to regulate just the right amount of airflow through the system, so when you manually close vents, you’re compromising its ability to do so, and risk causing extensive damage (even destroying the system).

We strongly recommend keeping your ducted AC vents open at all times, so that the system can work as intended, and provide optimal cooling for your home.

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