Don't Block Your Home's Cold Air Returns

Don't Block Your Home's Cold Air Returns

It may seem elementary to some homeowners, but for others who are unsure about the purpose of all those vents in the home's walls, floors or ceilings, know this: blocking cold air returns is a bad idea.

Sure, you know you shouldn't block the supply vents — the ones you feel the cold (or warm air) blowing out of — or you'll diminish the supply of cool or warm air in the home. You may also know that closing a supply vent can create negative pressure and make the system run inefficiently.

But what about the cold air returns? What are they, and why should you be careful to ensure they are never blocked?

When Return Vents Are Blocked

That air blowing out of your supply vents has to come from somewhere, and that's where the return vents come in. The system sucks in the air from the home and warms or cools it before it's distributed in the supply vents. Blocking the vents will keep the system from getting all the air it needs and any one or all of the following things may happen:

  1. The system will have to work harder to take in air, ultimately pulling it in through minute cracks in the home's exterior. The HVAC system's parts may wear out sooner than they should, and ultimately, malfunction and fail.
  2. The system may not be able to cool or heat as efficiently, driving up your utility bills and diminishing your comfort.
  3. You can actually freeze the air conditioner coils by blocking return vents. Frozen coils not only reduce your system's ability to do its job, but can damage the compressor.

Avoid Blocking Vents

Take a quick tour of your home every spring and fall to make sure all the return vents are free of blockages. Keep furniture and rugs off return vents; make sure the grills are clean and dust free. Ask your HVAC tech to check the vent ductwork when you schedule your spring and fall maintenance.

For more on keeping cold air returns free of blockage, contact Valley Heating, Cooling, Electrical of Silicon Valley.

Our goal is to help educate our customers in the South Bay Peninsula and Santa Cruz areas of California about energy and home comfort issues (specific to HVAC systems).