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.
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.