Shutting a room to save energy seems logical. In the cold winters of the Greater Cleveland area, you probably don't see a reason to heat spaces you don't use. The reality, however, is that closing registers can actually increase total energy use. This fact is substantiated in a 2003 study from Lawrence Berkeley National Laboratory.
Why Closing Registers Doesn't Help
When a register is closed, it stops air from entering the room, but air still comes into the duct. When the air can't get out through the register, it flows backward. Logically, it should flow back through the ducts and into other rooms, but that's not what usually happens.
Instead, the extra pressure created pushes the air out through small cracks in the ductwork before it ever reaches another room. By shutting a room to save energy, you're still using the air, but it's going to heat your attic, crawl space or basement instead of your living space.
The return air vents are another factor. These vents improve your system's efficiency by bringing conditioned room air back to the air handler. The return vent in a room continues to pull in air even if the delivery register is closed. Instead of pulling in conditioned air, though, pressure imbalances cause it to draw unconditioned outdoor air in through cracks around the window frames, molding and elsewhere.
Potential for Serious Damage
Shutting a room to save energy not only doesn't save you anything, it could also damage your heating and cooling system. High efficiency furnaces are carefully sized to meet each home's needs with all registers open. Closing a register forces the fan motor to work harder in attempt to overcome the blockage. This strains the motor and other components, potentially causing early failure.
If you want the option of redirecting and limiting airflow to certain rooms, consider having zoning installed. A zoned HVAC system uses dampers and a programmable thermostat for more precise control over the system's airflow.
For guidance on truly effective ways to save energy while keeping your home comfortable, contact us at P.K. Wadsworth Heating & Cooling wherever you are in the Greater Cleveland area.Follow @PKwadsworth
Paul Wadsworth is the President and Owner of P.K. Wadsworth Heating and Cooling. For 37 years, Paul has been providing heating and cooling services to the Greater Cleveland area. P.K. Wadsworth has been a trusted Cleveland HVAC service company for over 75 years. The company understand the area's construction and local heating and air conditioning needs. Paul has an MBA from the University of Michigan and a B.S., Industrial Engineering from Purdue University. Paul is the Chairman of COSE's Energy Advisory Council. He's been President of the Cleveland Air Conditioning Contractors of America and a founding member of the local chapter. Paul was born and raised in Cleveland and has been active in the local community. He resides in Cleveland, Ohio with his wife and two sons.
The opinions and statements contained in this article are for general informational purposes only and are not instructions. Only trained, licensed and experienced personnel should attempt installation/repair. The author assumes no liability for the opinions/statements made in this article. Any individual attempting a repair or installation based on this article does so at their own risk of loss.