Which device helps prevent outside air and pests from entering the home when the dryer is off?

Which device helps prevent outside air and pests from entering the home when the dryer is off?

• A. A ceiling fan
• B. A backdraft damper in the exterior vent hood
• C. A humidifier
• D. A dehumidifier

Answer: (B)

When the dryer isn’t in use, you want to stop outside air and pests from slipping back into the home through the vent. A backdraft damper in the exterior vent hood does exactly that. It’s a one-way flap that opens to let dryer air escape when the dryer runs, then closes when the dryer is off. The closing mechanism (spring or gravity) seals the vent, preventing outside air and small pests from entering. A ceiling fan moves indoor air and doesn’t block entry from outside. A humidifier adds moisture to the air inside, and a dehumidifier removes moisture from inside air; neither prevents air from coming in through the vent when the dryer is off.

When the dryer isn’t in use, you want to stop outside air and pests from slipping back into the home through the vent. A backdraft damper in the exterior vent hood does exactly that. It’s a one-way flap that opens to let dryer air escape when the dryer runs, then closes when the dryer is off. The closing mechanism (spring or gravity) seals the vent, preventing outside air and small pests from entering.

A ceiling fan moves indoor air and doesn’t block entry from outside. A humidifier adds moisture to the air inside, and a dehumidifier removes moisture from inside air; neither prevents air from coming in through the vent when the dryer is off.