At some point, we have all closed vents in unused rooms of our homes. One of the most common areas where vents are closed is in bedrooms and bathrooms that are reserved for our guests. Like many homeowners, you may believe that closing vents improves cooling in other areas of your home, and therefore, reduces your energy bill. Would you be surprised to know that closing your vents can actually increase your energy bill?
The Role of Air Conditioning Vents
Your air conditioning system has two types of vents — supply vents and return vents. You are most familiar with supply vents. Cooled air comes out of the supply vents, and you can feel the air flow come into each room of your home. The supply vents have louvers that can be adjusted to change the direction of the air flow. Return vents, though, have a more secretive role. These vents draw warm air from inside your home and deliver it back to the evaporator coils. The coils are chilled with refrigerant that removes heat from the air. Once the air is cooled, it is delivered back into your home through the ductwork and out the supply vents.
The Effects of Closing Your Vents
Depending on the type of vent you close, you may have certain problems with your air conditioning system. The most common problem we see that is related to closed or blocked return vents is freezing of the evaporator coil. The way your system works is that a certain volume of air needs to flow through the coils. When the air flow is less, the refrigerant causes the coil to freeze. Dirty filters on the return system can also reduce air flow, so we recommend that you change your filters annually. Because the warmed air is not returning to the evaporator coil, your home feels warmer, and you change your thermostat setting. The result? A higher energy bill.
When you close a supply vent, the cooled air is still delivered throughout the ductwork to the room. Instead of flowing through an open vent, the air circulates in the ductwork. Pressure pushes the air back through the ductwork, and it may eventually find a path to an open vent. Along the way, though, the amount of air inside the ductwork grows, and your ductwork is designed to handle a specific volume of air. The extra air places pressure on the ductwork. Over time, the pressure may damage the ductwork and seals, creating a leak. When you have a leak in your ductwork, the volume of air has to increase to deliver the same amount of cooled air into the home. Your air conditioning system has to run longer to maintain the same temperature, and your energy consumption gradually rises.
Options for Managing Your Energy Bill
The best way to manage your energy consumption is to keep all of the vents and doors in your home open. Doing so keeps the air circulating throughout your home, and allows the proper amount of air to be fed through the ductwork, supply vents and return vents.
If you want to better manage cooling temperatures throughout your home, call And Services to learn about our zone systems.