Should You Shut Furnace Vents For Better Energy Efficiency?

Brrr. Have you felt the chill in the air the last few nights? It’s enough to make your furnace kick into high gear.

It may also have you thinking about the utility bill that will be waiting for you in your mailbox next month.

Sudden cold snaps mean your furnace will run more than usual. And the more it runs – especially if it’s not as efficient as it could be – the more you’ll spend.

Looking for ways to save? Why not close the air vents in the few rooms in your home you really don’t use?

It seems like the right thing to do. You have a spare bedroom you rarely use. Or a playroom that hasn’t been used since the kids were small. Why not turn off the vent, shut the door, and only heat the rooms you truly use?

When your home was originally built, it was designed as a complete system. The ventilation system was routed throughout your home, to cover all of the rooms in your home. Furnace vents and registers were added to every room, along with cold-air returns to keep air movement running freely.

When you close off a register and shut the door, it creates pressure. This causes the return duct to pull in cold air from any source it can find: cracks along window or doors. The warm air is also trying to push up through the register, and will find leaks in the duct work if they aren’t sealed properly. And if those leaks happen to be in your attic, your basement, or crawl space, you’ll be heating places you never intended to heat.

There is also the possibility of damaging your furnace. If your furnace is newer, it was designed to heat a specific square footage. It was installed with maximum efficiency in mind. When you turn off a vent, it creates an unexpected blockage in the system. Because your furnace is designed for efficiency, it tries to overcompensate for the loss. The furnace works harder to distribute airflow to the intended places.

And if the winters are especially cold, it can leave parts of your home vulnerable to freezing. Think beyond your plumbing system; your ventilation system can freeze too.

Your best bet to keep your utility bills as low as possible is to keep your furnace running as efficiently as possible. This means cleaning your ducts every few years to ensure they are running at optimal efficiency. It also means maintaining your heating system on a regular basis to ensure everything is in good, working condition.

When was the last time a professional looked at your heating and ventilation system?