Keep heat vents open in your home for efficiency and energy savings.

Is one of your rooms unoccupied or not used during the wintertime? If so, you might be thinking about closing the heat vents, saving money on your heating bills, and enjoying a more comfortable home. However, closing off vents might not be a good idea and here are several good reasons to consider leaving the vents open. Not to mention keeping the heating vents open will even really help you save money on your utility bills. The biggest reason for keeping the vents open is for efficiency, as when the HVAC system is more efficient it costs less money to run.

1. Air Leaks in the Duct System
When you close a vent in one part of the house, it affects the airflow in another section. To work properly and most efficiently (thus saving you money), your furnace and air conditioning system produce static pressure within the ducts. To maintain efficiency, the blower needs to suck in the same amount of air that it blows through the vents. Closing a vent or two can increase the pressure within the ducts. This excessive pressure can create air leaks or make leaks worse.

2. You May Use More Energy
If you are closing vents to save on heating bills, you may end up paying more. For example, some furnaces have ECM motors which can adjust speed to allow for demand. However, when you raise the pressure in the ducts, the blower must increase its speed because of the resistance from the increased pressure. When the blower motor speeds up, it uses more energy.

If your home has a variable motor in the HVAC system, and if your heating vents are closed. The motel will work longer and “harder”, making shortening the lifespan and leading to additional energy bill use. A Standard motor and fan can lead to more leaks in the duct system.

 

 

3. Efficiency May Go Down
Instead of ECM blowers (electronically commutated motors), some blowers use permanent split capacitor (PCM) motors. A PCM motor cannot adjust speed to meet demand so it slows down when the pressure increases. If the blower slows down, it cannot deliver enough heat and the system may not get proper oxygen.

4. Vent Closing May Cause Heat Exchanger Problems
If your furnace cannot properly circulate the air, heat may build up within the heat exchanger. In a gas furnace, the HE or heat exchanger is made of metal tubes which contain air heated by the furnace burner. Warmed air gets blown into the duct system by the blower fan. The exhaust goes out the vent. If too much heat is inside the HE, it may crack and create a dangerous situation. This can lead to more costs and maintenance issues of your HVAC system in the future.

Carbon monoxide (CO) is inside the heat exchanger and if the HE gets cracked, it may leak into the area where the furnace is located and can get inside the home. Since you cannot smell, see, or taste carbon monoxide, you may unaware it is there. CO takes the place of oxygen in your blood and you or your family may fall asleep and never awaken.

 

 

Things to Remember
If you close some of the vents in your home it may increase air pressure in the ducts. Raised pressure can cause leaks or make leaks worse, making your furnace work much harder. Your furnace blower may lose its efficiency or need to increase speed, resulting in more power consumption and thus higher utility bills. Closing vents may cause overheated heat exchangers to develop cracks or leaks, causing dangerous carbon monoxide gas to enter your home. To make sure your home is safe, schedule a furnace tune-up with your local HVAC service and install CO detectors if you have a gas or oil-burning furnace.