Central Air Conditioning Closing Vents

Air pressure inside supply ducts increases in proportion to the number of vents closed and pushes still greater amounts of conditioned air out of existing leaks.

Central air conditioning closing vents.

Environmental protection agency estimates that most homeowners lose 20 percent of the cool air they re paying for right through their home s ducts. The belief is that closing a vent will simply push the air onward to other parts of the home improving energy efficiency. Before closing any vents in your home. The average home loses 20 30 of the air blowing through it thanks to air duct leaks according to energy star.

The ideal system also has low duct leakage. In a well designed system the blower moves the air against a pressure that s no greater than the maximum specified by the manufacturer typically 0 5 iwc. In fact it could even cause your energy costs to increase. Particularly if the registers are not sealed to the drywall opening.

Ensure that your ducts are properly sealed and connected. But when you close a vent yes even just a few it increases the pressure inside the ducts. This causes a couple of problems. Many homes lose even more.

The typical system however is far from ideal. Homeowners typically close vents in an attempt to redirect air away from unused spaces. You see your ac pushes out cool conditioned air through your ductwork and into your home. Closing ac vents increases energy bills if you close your ac vents you actually increase the amount of conditioned air that gets wasted via duct leaks.

That means the ductwork was sized so that amount of air going into your air conditioning system equals the volume of air going out of your system. So when you shut some vents you are messing up the balance of your ac system. Your furnace or a c runs longer. Through small openings joints cracks and around closed windows and doors through a process called infiltration.

Closing air vents is a popular strategy for adjusting air flow in the home but it s not necessarily a good one. In a 2003 study the lawrence berkeley national laboratory discovered that register closing led to increased energy use. When you close vents pressure builds up in your ducts. Through mechanical ventilation devices such as bathroom or kitchen fans that vent to the outdoors or heating ventilation and air conditioning hvac systems with a fresh air intake.

That means you re paying 20 to 30 more than you should on your utility bills. But this is an average. Closed vents increase pressure. As it turns out closing air vents in a home with a modern central heating and air conditioning system does little to save energy.