Closing Off Central Air Vents

In a 2003 study the lawrence berkeley national laboratory discovered that register closing led to increased energy use.

Closing off central air vents.

When you shut off the vents you can increase the pressure in your ductwork which can back up into your hvac and cause issues. In fact it could even cause your energy costs to increase. Your air ducts make it worse. Why closing air vents doesn t work.

Thus your system becomes oxygen deprived. The belief is that closing a vent will simply push the air onward to other parts of the home improving energy efficiency. Homeowners typically close vents in an attempt to redirect air away from unused spaces. As it turns out closing air vents in a home with a modern central heating and air conditioning system does little to save energy.

This can increase your energy bills and even lead to premature breakdown of your ac if you close too many vents. Permanent split capacitor psc blower closing vents causes this blower to slow down because it can t overcome the extra pressure. Wasted cool air in the attic moves from 20 to 25 of the total but the closed off room is considered worth it. In addition this increased pressure places strain on your air ducts.

The study also found that whatever benefit was derived from closing air vents was largely offset by increased duct leakage. What impact does closing vents have on an hvac system. As if a damaged system isn t bad enough closed air vents can cause ductwork to leak or burst. If it s a typical duct system with 60 higher static pressure than the maximum specified closing even one register could send the system over the edge.

The issues your hvac experiences due to closed vents are like problems caused by dirty air filters including inadequate airflow turning off and on frequently and premature hvac breakdown. Yes your system may be fine if you close a register or two in your home but the results will depend on how restrictive and leaky your duct system is. Taking a home system with 4 equal size vents and an attic leakage equal to one vent each moves 20 of air. Like the idea that cranking the thermostat all the way up or down heats or cools a house quicker the notion that closing some household.

Closing vents disrupts this balance and creates pressure in your system which causes your air conditioner to work harder. Closing vents will cause different problems depending on the type of blower. But when you close the registers in unused rooms the pressure builds and turns those small leaks into big problems.