The HVAC vents, in many homes, have fins that can adjust using a sliding switch. The fins can direct airflow at a set angle, however, if you push the switch completely to one side, you can close off the vent.
You might think this is a great way to save energy. After all, if you close off the vents in an unused room, the hot or cold air won’t enter the room. Closing the vent does not save money. In fact, it can increase your utility bill and cost you more money in the long run, due to repairs.
A Counterproductive Strategy
It’s easy to understand the hypothesis. If hot or cold air is not escaping the vents in a room or two, it should use less energy to produce the air needed to heat or cool the remaining rooms. However, an HVAC system is not designed to operate that way.
An HVAC system is like a human respiratory system. For it to work, efficiently, there must be proper airflow. Many systems are calibrated so that it can change the airflow. This can choke out some of the energy efficiency and put a strain on the HVAC system components.
Close vents that increase the pressure in the ductwork and the pressure increases all the way back up to your HVAC system. This forces the system to work harder. This may cause the same issues as when you have a dirty air filter. The air conditioner or furnace will use more energy to make the same amount of treated air.
This will increase your monthly bill. It also puts stress on motors, fans, or other equipment, reduces maintenance intervals and leads to frequent repairs.
One other problem created by excessive amounts of duct pressure is that it causes duct leaks. These weak spots in ductwork can turn into open gaps in the ducts. This allows the treated air to escape and this forces your systems to work harder.
Get in The Zone
The concepts behind keeping vents closed in an unused room can be put to work as long as you have the correct HVAC system. Some systems, including the “zone HVAC system”, offer you unprecedented control over the rooms that will receive the treated air.
This sophisticated interface is not the same as a standard thermostat. With a zone system, you can assign a different temperature to each zone. A zone can be a section of your house or just a single room.
This can come in handy when you want to save energy. You can treat a room to a lower or higher temperature, without closing the vent or shutting off the airflow into the room completely.
There’s no reason for an unused or unoccupied room to maintain the same comfort level as the rest of your house. However, the lack of an HVAC system can lead to summer humidity damage, frozen winter pipes, and mold.
If you want to learn more about controlling HVAC zones and what it takes to upgrade your home’s system. For more information, contact one of your local HVAC contractors in Philadelphia.