Does Closing My Air Vents Save Energy?

Air vent

With the rising summer temperatures here in Florida, some people may close the registers in some rooms of their homes thinking this will make their HVAC system work less and will save energy.

The vents located in the rooms of your home are called registers. Cool air is pumped from your AC into your home through these registers. The idea of closing them to save energy seems to make sense according to the thought process that with fewer rooms to cool, your AC won’t have to work as hard.

Unfortunately, not so much…

Leave Them Open

It turns out that by closing the registers in order to save both money and energy causes your equipment to both work harder and could also lead to safety issues and hefty repair bills.

The Lawrence Berkeley National Laboratory conducted a study in 2003 to find if closing the vents in unused rooms worked to save energy. Their results were somewhat surprising:

  • Closing registers to slash energy actually caused your system to use more energy. The increased pressure in the duct systems caused subsequent duct leaks that outweighed any energy savings.
  • Closing too many registers in the home caused airflow resistance that majorly restricted air flow through the entire system and also lead to safety concerns, such as dangerous damage.
  • Closing those registers closest to the main air handler increased duct pressures and also lead to air leaks throughout the entire system.

The laboratory obviously came to the conclusion that closing the vents in your home does NOT lead to saving energy or money, but exactly the opposite!

The Bottom Line

Closing the vents in the summertime humidity collects on the register’s inner surface. This added humidity can lead to mold, mildew and other unsightly pathogens that could become dangerous if left untreated. Homeowners should be aware that closing the registers in rooms will often lead to more problems instead of an energy-saving solution.