Did you know that you could be subjecting your HVAC system to a series of unintended consequences if you close vents in unused rooms? It turns out that you may not save money by closing vents– and you could be causing a world of problems.
As you probably realize, HVAC systems use a lot of energy, perhaps as much as half of all your home’s energy usage. While home HVAC vents usually have levers that allow for adjustment, they also allow the vents to be closed.
Understanding Air Distribution
Your air conditioning and heating system’s blower pulls in air from inside your home through the system’s return air ducts. If you have a high-efficiency system, you have an ECM motor– or an electronically commutated motor.
When you further consider that most older home HVAC systems are far from ideal anyway, that makes the problem worse.
Whichever is the case for you, the HVAC system is designed so that the blower pushes against a maximum pressure difference. When the filter is dirty or the supply ducts are restricted– as when ducts are closed– the blower must push against a higher pressure than it was designed. Neither kind of blower can perform properly under that condition.
Why Closing Vents Is A Bad Idea
Closing vents increases system pressure, and that’s bad. Take note that this issue impacts both heating and air conditioning, and closing vents is a bad idea no matter which HVAC system you have turned on.
When you close vents, you may create the following consequences:
- Greater air duct leakage
- If you have a PSC blower, lower air flow
- If you have an ECM blower, higher energy usage
- Because of restricted airflow, comfort issues in your home
- Freeze-up of your air conditioner coil
- Dead compressor from the extra strain
- Cracked heat exchanger and the potential for carbon monoxide leakage inside your home
- Because of unbalanced system issues, increase in particulate matter brought in to the home
- Condensation and related mold growth in rooms with closed vents where the HVAC dehumidification effects don’t work full
- and more.
Of course, you may not experience all of these problems from just one or two closed vents, but why take the risk?
As you probably realize, HVAC systems use a lot of energy, perhaps as much as half of all your home’s energy usage. Your air conditioning and heating system’s blower pulls in air from inside your home through the system’s return air ducts. Closing vents increases system pressure, and that’s bad. It’s hard on the blower– and since most home duct systems aren’t sealed, it means more duct leakage. Take note that this issue impacts both heating and air conditioning, and closing vents is a bad idea no matter which system you have turned on.
In the best case scenario, your HVAC system is carefully balanced to provide maximum heating and cooling throughout your home. Closing vents interferes with the way the system works.
In the worst case scenario, your system wasn’t designed very well in the first place or has perhaps been negatively impacted by dirt, neglect and age. It doesn’t perform with optimal efficiency anyway, and closing air vents could put enough stress on the system to cause it to fail.
If you’re experiencing problems keeping your home comfortable and are considering closing off unused rooms or making an adjustment to your HVAC system, don’t take action without consulting with our experts. There are ways to solve every heating and air conditioning problem correctly, and we can help you find them.