State HPWH Inlet/Outlet Duct - Manual

Ducting Kit Installation Instruction for Hybrid Electric Heat Pump Water Heaters
Introduction:
Heat is absorbed from air entering the inlet (left) side of the
compressor unit on top of the water heater and transferred
to the water inside the storage tank. Cooler dehumidified air
exiting the outlet (right) side of the compressor unit is a normal
byproduct of operation. In standard installations (using ambient
air) a minimum installed space of 750 cubic feet is required as
a source of heat. Duct adaptors can be used to redirect inlet
and/or outlet air from or to other locations to permit installation
in confined spaces, improve performance and maintain comfort
in occupied areas of the home.
See the instruction manual that is shipped with the water heater
for further instructions on using ducting kits for installation in
confined spaces of less than 750 cubic feet.
Installation Limitations:
There are two duct adaptors; one connects to the inlet side of
the top shroud and one to the outlet side. The two cannot be
interchanged. Ensure the correct adaptor(s) is ordered prior
to installation. Installation of the duct adaptors requires field
supplied 8-inch flexible duct that can be obtained from a local
HVAC supply store or home center. Use of smaller diameter
ducting is not permitted.
Air can be drawn from or expelled to the outdoors, an attic
space, or to another room inside the home.
*The maximum length of flexible duct allowed is 10 feet.
**Ducting can be connected to the inlet, outlet or both the inlet
and outlet (requires both duct adaptors), though the total length
of duct must not exceed 10 feet. For example: when redirecting
inlet and outlet air, a maximum of 5 feet of inlet duct and 5 feet
of outlet duct is allowed. Variations such as 3/7 feet, 7/3 feet
are also permitted, as long as the total duct length does not
exceed 10 feet.
Installation Considerations:
The compressor unit on the water heater is disabled when the
temperature of the air flowing to the inlet is lower than 45°F
(7.2°C) or higher than 109°F (42.8°C). Air expelled from the
outlet will be 7°F (4°C) to 9°F (5°C) cooler than the inlet air.
These operational parameters must be considered when deter-
mining if a location to duct air from/to will be suitable.
IMPORTANT NOTE:
If the compressor unit is disabled for long periods of time due
to inlet air temperature being too hot or too cold, the potential
energy savings a heat pump water heater is able to provide
may be significantly reduced.
323471-001 Page 1
Air Inlet:
• Outdoor air temperatures will often be lower than 45°F
(7.2°C) in many regions during fall and winter months.
• Attic temperature will often exceed 109°F (42.8°C) in many
regions during spring and summer months.
• For units installed in conditioned spaces - ducting outdoor
air to the air inlet of the unit may place additional load on
space heating and cooling equipment unless the air outlet
is also ducted to an alternate location.
• Air being drawn from an alternate location inside the home
may cause a negative pressure condition inside that area.
As a result, cold or hot air from outdoors may be drawn into
the structure and place additional load on the space heat-
ing and cooling equipment.
Air Outlet:
• The air outlet from a unit installed in a garage or any area
where solvents or other chemicals that emit potentially
harmful fumes are stored or automobiles are located must
never be ducted to any other space inside the building
structure. This would include all occupied and unoccupied
spaces such as attics or basements. Potentially harmful
fumes and vapors from solvents and cleaners or automo-
bile exhaust gases could be introduced into living spaces.
• Cold air blowing from the outlet into an alternate location
inside the home may cause cooling discomfort and be
objectionable.
• Cold air blowing from the outlet into an alternate location
inside the home may place additional load on space heat-
ing equipment during fall and winter months.
• Ducting outlet air only to an alternate location may cause a
negative air pressure in the installed space. As a result cold
or hot air from outdoors may be drawn into the structure
and place additional load on the space heating and cooling
equipment.