Baby, it's cold outside!
It's cold and those oil and natural gas prices are enough to make you cringe when you open your heating bill. It's tempting to close aire registers in any rooms you don't use. Closing vents to a bedroom or bathroom that you're not using seems like a sensible way to increase energy efficiency. With the door and vents shut, no heat should pump into the room, freeing your heating, ventilation and air conditioning system (HVAC) to heat the rest of your house. Closing the air registers in rooms you don’t use seems like a good way to potentially save money, but there are some things you might want to consider before closing those registers.
But because the rooms in your home have cold-air returns as well as heating vents, shutting the vents doesn't prevent air movement, it actually interferes with your home's energy efficiency. It creates pressure in the closed-off room, which causes the return duct to pull in cold air from any cracks in windows or doors. In addition, the warm air still trying to push up through closed vents will start to leak out any ducts that aren't sealed properly, or it will be forced back down into your basement or into floor cavities. So, you'll still be paying energy costs for heat, just in places you can't use.
It's also possible to damage your furnace by closing too many air vents. Newer, high efficiency models are designed to operate with your specific square footage in mind and with fans running at full speed. Closing off vents creates unexpected blockages, which forces the furnace to work harder when distributing heated air. When you block a vent, your HVAC system’s blower motor will either have to work harder to push air through your home, or it may spin at a lower speed. It's not good for the blower motor to have to push against a higher pressure. the more vents you close, the higher the pressure, and the less efficient your system due to that leaking air. It's also possible that limited air flow, especially in winter, may cause freezing in your ducts, meaning more work for your heating and air conditioning system. So this not only lowers the energy efficiency of your heater, but shortens its life.
Low air flow can also cause the condensation on your coils to freeze and can cause damage to your compressor. If you have a furnace, low air flow can be dangerous. Low air flow in a furnace can get the heat exchanger hot enough to cause cracks. Those cracks then allow exhaust gases to mix with your conditioned air. When that happens, your duct system can become a poison distribution system as it could be sending carbon monoxide into your home. (Which is another good reason to have working carbon monoxide detectors in your home.)
You can improve the efficiency of your heating system in several ways, starting with a furnace upgrade. Older models operate in the 55 percent to 70 percent range of energy efficiency, while newer models operate at 95 percent to 98 percent. Even though a new furnace carries a hefty price, a more efficient unit can significantly lower your energy usage and thus your energy costs (not to mention the environmental savings). You should also have your furnace cleaned every few years and ensure all the ducts are tight and properly sealed. If you live in a home with multiple stories, it's okay to partially close upstairs vents while fully opening those downstairs. Because heat rises, the top floor often steals most of the heat. So partially closing vents can help keep other aeas warmer without damaging or stressing your HVAC system.
Using your heating system properly and making energy improvements will not only save you money, but when you decide to sell your home it will stand out from the less efficient competition! I can ptovide you with additional information on ways to upgrade your home's energy efficiency. Contact me if you’d like to learn more!