Are you looking for ways to save money on heating and cooling costs and considering closing vents in unused rooms? Before you do, keep reading. Closing vents doesn’t save you money, and it can cause your AC or heat pump to run inefficiently and eventually break.

Closing vents doesn’t save you money.

Closing air vents will not help your AC unit to run less. Therefore, not saving money as you had hoped.

Here’s why.

Your HVAC system works much like your lungs. Imagine walking at a brisk pace inhaling through your mouth and exhaling through your nose. Your central HVAC moves air in much the same way. The blower pulls air from the house through the return ducts. Then, pushes it back into the house through the supply ducts.

Now, imagine if you closed off one of your nostrils, but you continued to walk at the same pace. You’re still trying to move the same amount of air, but now you have fewer pathways to do so. So, you either move less air (depriving yourself of oxygen) or you have to put in more effort to breathe comfortably.

When you close a supply vent, you’re causing your air conditioner to work harder and increase the pressure in your air ducts.

Closing vents in unused rooms can cause different problems.

If you have a Permanent Split Capacitor (PSC), blower it can cause it to slow down because it can’t overcome the extra pressure, essentially making it “oxygen deprived.”

Heat and air systems with an Electronically Commutated Motor (ECM) blower can adjust its speed to varying conditions. However, when you close the vents, it will ramp up to overcome the extra pressure, which will INCREASE your utility bill.

Closed vents can hurt your HVAC system.

So, it doesn’t save you money, but how can it hurt your HVAC system?

The most common blower in residential air conditioning is the PSC blower. Since closing off the air vents slows it down, it delivers less air to the evaporator coil in the AC unit. When this happens, the coil gets too cold and turns it into a block of ice. This “freeze up” causes the refrigerant to eventually flow back to the outdoor unit’s compressor and destroying it.

Over time, the diminished airflow also damages the furnace heat exchanger by causing it to overheat and possibly crack.

The evaporator coil and heat exchanger are expensive to repair and replace. If you find yourself in this situation without a warranty on the parts, then AC replacement is the more cost-efficient option.

Other important problems from closing vents in unused rooms.

We’ve talked about the most important issues with closing vents in unused rooms. But it can also cause problems with comfort levels and increase the likelihood of duct leakage.

Have any other questions about the do’s and don’ts of cooling and heating your home? If you live in the Northwest Arkansas area, contact us with your questions. Our Advantage Air & Service professionals would love to help.