Hansberger Refrigeration Blog: Your AC Repair Resource

Why You Shouldn’t Shut Registers for Temperature Control

Why You Shouldn’t Shut Registers for Temperature ControlIt just seems to make good sense, doesn’t it — the idea of shutting registers for indoor temperature control? It looks as if you could save money on utilities by not letting in conditioned air to rooms that aren’t in use, thereby shunting it to the areas that do need it.

Only your HVAC system isn’t designed to work that way. Here’s what happens when you shut vents or registers in a room.

Shutting Vents

Your HVAC system was sized (hopefully correctly) to produce a certain capacity of conditioned air in your home. It does so whether the vents are open or closed. However, when vents are closed, the air that would normally go into the closed-off room has to go somewhere. What happens is the pressure forces the conditioned air through cracks around windows and doors, into the basement, through unsealed ducts and info floor cavities.

In addition, shutting vents or registers may also cause the HVAC to work harder to pull in return air. To get sufficient return air, the unit may pull cold or hot air from outside the home through cracks rather than from the already conditioned air in you home. This means your HVAC system is working inefficiently and you’ll be paying more on your utility bills.

Malfunctions and Breakdowns

Anytime your HVAC system is working harder than it should will result in more wear and tear, and lead to breakdowns faster than might happen otherwise. Some other problems that can occur:

  • Closed vents may slow down the blower as the system is deprived of air.
  • An electronically commutated motor, or ECM, will adjust speed according to conditions, so will ramp up to overcome extra pressure when vents are closed. That means bigger bills.
  • Lower air flow from blocked vents may cause the evaporator coil to freeze. Eventually, liquid refrigerant will flow back to the compressor and destroy it.
  • Low air flow may also cause the furnace’s heat exchanger to overheat and possibly crack.

For more on regulating indoor temperature by blocking registers, contact Hansberger Refrigeration and Electric Company. We serve Yuma and the surrounding area.

Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 928-723-3183.