Maritime Geothermal TF-45, Installation And Service Manual

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Page 18 001223MAN-05 1-Jul-2017
TABLE 10 - Heat Pump Size vs. Hot Air Grills
Model Size (tons) # of Grills (@100 cfm)
45 3 12
55 4 15
65 5 19
75 6 21
80 6 24
TABLE 11 - Plenum Heater Sizing
Heat
Pump
Plenum Heater Sizes (kW)
Model
Size
Recommended Possible
45 10 5, 7, 10
55 10 5, 7, 10, 15, 20
65 15 5, 7, 10, 15, 20
75 20 5, 7, 10, 15, 20
80 20 5, 7, 10, 15, 20
Duct Systems - Grill Layout
Most forced air heating systems in homes have the floor grills
placed around the perimeter of the room. Supply grills should
be placed under a window when possible to help prevent con-
densation on the window. As mentioned in the previous sub-
section, supply grill leads should be 6'' in diameter (28 square
inches each) to allow 100 cfm of air flow.
In a typical new construction, there should be one supply
grill for every 100 square feet of area in the room. When rooms
require more than one grill, they should be placed in a manner
that promotes even heat distribution, such as one at each end of
the room. It is always a good idea to place a damper in each
grill supply or place adjustable grills so that any imbalances in
the heat distribution can be corrected.
The total number of supply grills available is based on the
heat pump nominal airflow. TABLE 10 shows the number of
grills recommended per heat pump size.
Return grills should be mounted on the floor. At minimum
they should be the same size as the supply grill, it is highly rec-
ommended that they be 25% to 50% larger than the total
supply. They should be placed opposite the supply grills
when possible to ensure distribution across the room. For
rooms requiring more than one supply grill, it may be possible
to use one larger return grill if it can be centrally positioned op-
posite of the supply grills, however it is preferred to have one
return for each supply to optimize heat distribution across the
room.
Thermostat Location
Most homes are a single zone with one thermostat. The
thermostat should be centrally located within the home, typically
on the main floor. It should be placed away from any supply
grills, and should not be positioned directly above a return grill.
Most installations have the thermostat located in a hallway, or
on the inner wall of the living room. It should be noted that most
homes do not have any supply ducts in the hallway. This can
lead to a temperature lag at the thermostat if there is very little
air movement in the hallway, causing the home to be warmer
than indicated by the thermostat.
Plenum Heater (Optional)
For installations that do not already have a backup heat
source such as electric baseboards, wood stove, propane, etc.,
it is recommended that a plenum heater be installed. This pro-
vides two functions.
The first function of the plenum heater is to act as an auxil-
iary heat source. As such it will provide additional heat on ex-
tremely cold days if the heat pump is unable to bring the home
temperature up quickly enough, eliminating any discomfort to
the homeowner. This is particularly important if the heat pump
is intentionally sized to less than 100% of the calculated heat
load.
The second function of the plenum heater is to provide
emergency heat should a heat pump problem occur. This can
be engaged by setting the thermostat to emergency heat, allow-
ing the plenum heater to function while preventing the heat
pump from operating. Should the heat pump fail while the home
is vacant, the auxiliary function of the thermostat will maintain
the temperature setting of the thermostat.
INSTALLATION - Blower outlet at top of unit: See dia-
gram on following page. The heat pump comes equipped with
an internal mounting location for the plenum heater. Remove
the screws from the cover plate, remove the cover plate and
place the plenum heater in the hole. Slide it up and secure the
bottom flange with three cover plate screws. Use the indicated
knockouts on the heat pump cabinet for electrical connections.
When installation is complete, check the appropriate
box of the label on the unit door to indicate which size heat-
er was installed.
INSTALLATION - Blower outlet at side of unit: The ple-
num heater should be installed in the supply duct in a manner
that allows the vast majority of the airflow to pass through it to
prevent any hot spots in the heater elements. Ensure that the
plenum heater is mounted in an approved position as per its
instructions.
Only two control wires are needed to connect the plenum
heater to the heat pump terminal strip . Refer to the label on the
plenum heater or the electrical box diagram on the inside of the
electrical box cover of the compressor unit for details on the
connections.
The plenum heater requires its own separate power
supply. TABLE 11 shows the recommended size plenum
heater. Refer to the Electrical Tables for wire & breaker size
information.
Condensate Drain
The unit comes equipped with a 3/4” PVC socket fitting
(female) labeled “Condensate Drain”. This drain allows the con-
densate which is removed from the air during cooling mode to
drain from the unit. The drain should be connected as per local
codes. During high humidity weather, there could be as much
as 25 gallons of water formed per day. A condensate pump
may be required if there is not a floor drain close by.
Care should be taken in the spring to ensure that the drain
pipe is not plugged with dust that has collected during the winter
causing the condensate to overflow into the bottom of the heat
pump and onto the floor (although there is a safety control to
prevent this). The condensate drain is internally trapped;
however, proper venting is required external to the heat
pump. Refer to local codes to ensure the installation is
done properly.
DRAWING 002222PDG shows a typical installation.