should i close air ventsDo you have a room in your home that’s ten times warmer than the rest of your home? Perhaps it’s your laundry room or a bedroom. If it’s a room you don’t use a lot, you probably think it makes sense to close the air vent. After all, why heat a space you don’t use? Many Maryland homeowners think closing vents will make them more comfortable in other parts of the house and possibly save energy. However, heating experts caution you from closing air vents.

Why closing air vents is a bad idea

HVAC vents or registers have a lever on them allowing you to open and close them. So it makes sense that homeowners think they should open and close them as needed. While it seems like an efficient way to save money on your heating and cooling bill, it has the opposite effect. Your costs may go up, you could damage your heating and cooling system, and your comfort doesn’t improve. Here’s why.

Your HVAC system doesn’t work less when you close vents. You just change where the air comes out. Closing vents causes pressure to build up in the duct system. HVAC contractors design the system to push against maximum pressure difference. So, your system can’t work as designed when you close HVAC vents. The more you close, the higher the pressure buildup and the harder your system works. When your HVAC system works harder, it shortens the lifespan.

The increased pressure also affects your ductwork. It causes duct leakage. It’s one of the top three ways you waste energy at home. Why does it happen? The air needs somewhere to go. Since it can’t find its way out of the shut air vent, the air finds its way out through ductwork leaks.

How closing air vents damage your HVAC system

Your blower is the heart of your HVAC system. It distributes the conditioned air by pulling air from return vents and pushing it back through your home. There are two types of blowers. Depending on the type you have, closing vents could cause other problems too.

Most people have a PSC blower. Closing air vents with this type of blower slows down airflow. So, your air conditioner’s evaporator coil receives less air. With less air traveling over it, the coil may get too cold and ice over. Since the coil cools your air, closing an air vent effects your comfort.

When there’s less airflow, it causes heating concerns too. The heat exchanger on your furnace may overheat and crack. When that happens, it can cause a carbon monoxide issue in your home.

If you have the other type of motor, ECM, the pressure causes your motor to work harder.

With both types of motors, your system isn’t working like it should when you close air vents. It causes the following problems:

  1. Increased air pressure in the duct system
  2. Duct leakage
  3. Decreased comfort
  4. Dead compressor
  5. Cracked heat exchanger

Closing air vents may cost you money rather than reducing your utility bill.

How to make your home more energy efficient

Since you probably closed air vents to make your home more energy-efficient and improve the comfort in some rooms, how can you lower utility bills? Start with an energy audit to find sources of energy loss. Your home probably has several.

Homeowners waste between 10 and 50-percent of the energy created in their home. It’s like throwing money out the window. An energy audit finds all the ways your home wastes energy and identifies solutions.

Minnick’s is a pioneer in Whole-Home Comfort. We believe your comfort depends on more than your HVAC system. Your entire home is one system, and its performance depends on how all the parts work together.

An energy audit only costs $100 for BGE and Pepco customers. Minnick’s is an approved BGE and Pepco contractor, serving Montgomery and Howard counties. If you make the suggested home improvements, the utility companies offer up to $7500 in rebates. You also get free energy saving products.

There are more than two dozen other ways to lower your utility costs, too. Let us know if we can help improve your comfort.