Central Air Conditioning Closing Vents

Before closing any vents in your home.

Central air conditioning closing vents.

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. Homeowners typically close vents in an attempt to redirect air away from unused spaces. Ensure that your ducts are properly sealed and connected. You see your ac pushes out cool conditioned air through your ductwork and into your home.

The belief is that closing a vent will simply push the air onward to other parts of the home improving energy efficiency. Particularly if the registers are not sealed to the drywall opening. Closed vents increase pressure. Leaking or burst ductwork.

Through small openings joints cracks and around closed windows and doors through a process called infiltration. But this is an average. 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. Many homes lose even more.

Your furnace or a c runs longer. Closing air vents is a popular strategy for adjusting air flow in the home but it s not necessarily a good one. 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. 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. Closing vents worsens that leakage problem because the extra pressure forces moreair out of those leaks. The ideal system also has low duct leakage. The average home loses 20 30 of the air blowing through it thanks to air duct leaks according to energy star.

As it turns out closing air vents in a home with a modern central heating and air conditioning system does little to save energy. So when you shut some vents you are messing up the balance of your ac system. This causes a couple of problems. But when you close a vent yes even just a few it increases the pressure inside the ducts.

In a 2003 study the lawrence berkeley national laboratory discovered that register closing led to increased energy use. In fact it could even cause your energy costs to increase. That means you re paying 20 to 30 more than you should on your utility bills. The typical system however is far from ideal.