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.

As if a damaged system isn t bad enough closed air vents can cause ductwork to leak or burst. In fact it could even cause your energy costs to increase. Closing one increases attic leakage by 5 and increases flow to the other 3 vents by 5 each. What impact does closing vents have on an hvac system.

Closing vents disrupts this balance and creates pressure in your system which causes your air conditioner to work harder. Closing air vents is a popular strategy for adjusting air flow in the home but it s not necessarily a good one. 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.

Thus your system becomes oxygen deprived. This can increase your energy bills and even lead to premature breakdown of your ac if you close too many vents. In addition this increased pressure places strain on your air ducts. As it turns out closing air vents in a home with a modern central heating and air conditioning system does little to save energy.

When you shut off the vents you can increase the pressure in your ductwork which can back up into your hvac and cause issues. 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. 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. 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.

Permanent split capacitor psc blower closing vents causes this blower to slow down because it can t overcome the extra pressure. Taking a home system with 4 equal size vents and an attic leakage equal to one vent each moves 20 of air. Closing vents will cause different problems depending on the type of blower. Why closing air vents doesn t work.

But when you close the registers in unused rooms the pressure builds and turns those small leaks into big problems. Your air ducts make it worse. The study also found that whatever benefit was derived from closing air vents was largely offset by increased duct leakage.