Rheem ProTerra hybrid heat pump water heaters have both an inlet duct and outlet duct. The inlet duct pulls air into the condenser. The air then heats the water. Additionally, dehumidified air from the water heater is exhausted via the outlet duct.
There are a few conditions where you’d consider ducting.
An ideal location would be a room that has greater than 700 cu ft. If the area of your water heater is smaller than 700 cubic feet and you don’t have the option of installing a louvered door then you may consider ducting air from outside the room using the inlet duct.
If your water heater is located in a conditioned space like a laundry room you can expect cold dehumidified air to exhaust from the outlet duct. It can reduce the temperature of the room by a few degrees. Some homeowners choose to duct the cold air outside of a conditioned room.
Always check with local building and HVAC codes before designing the air duct system. Do not connect the water heater to existing ductwork; it must be ducted separately from other appliances. Ducting must be adequately supported along both vertical and horizontal lengths. UL Certified terminations must be used for ducting to the outside.
For more information on how to properly duct a heat pump water heater contact us.