Honeywell, Fresh Air Ventilation System, Intake Duct, -20 to +160 °F Temperature, 24V Transformer;Damper/Actuator;Mounting Hardware for Control;Homeowner Information Label Included, 4-3/16 in L x 1-1/4 in W x 5-3/4 in H Today’s homes are built tight for energy efficiency,but that same tightness can also restrict the intake of fresh air and trap dust, allergens and more.The average person spends 9% of his or her time indoors, breathing in stale air. In fact, poor indoor air quality ranks among the top five environmental risks to public health. Honeywell offers whole-house ventilation, for bringing fresh air into your home while still helping you maintain energy efficiency.