Maritime Geothermal ATF-45, Инструкция по установке и обслуживанию

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Page 8 002000MAN-01 1-Jun-2018
ATF Sizing
Plenum Heater Sizing
Plenum heaters are available as accessories in 5, 7, 10,
15 and 20kW sizes. Choose a size that covers 100% of the
coldest day heat load, according to the heat loss analysis men-
tioned in the last section. If that is not available, use the follow-
ing recommendation:
This is which unit size is required for a
typical
two-level
home (main level and below grade basement) with R-20 walls,
R-40 ceiling and average size and number of windows. The
Heated Area is the area of the main level. The table accounts
for a basement the same size as the heated area.
IT IS HIGHLY RECOMMENDED THAT A PROPER HEAT
LOSS/GAIN ANALYSIS BE PERFORMED BY A PROFES-
SIONAL WITH APPROVED CSA F-280 SOFTWARE BEFORE
SELECTING THE SIZE OF UNIT REQUIRED FOR THE APPLI-
CATION.
The analysis will result in a heat load for the coldest day,
which is influenced by, for example, the number of levels, the
size of the windows, the orientation of the home, attached gar-
age, bonus rooms, walk-in basement, and coldest outdoor tem-
perature for the region.
In northern climates, a heat pump model size can be se-
lected by matching the calculated heat load to a heat pump’s
standard capacity rating at an outdoor temperature of 35°F
(1.7°C), which is the AHRI H2
2
test condition. These are listed
in the Model Specific Information section later in this manual.
This sizing will result in a good compromise between covering
as much of the cold weather heat load as possible without utiliz-
ing backup heat, while minimizing excessive cycling (turning on
and off frequently) during moderate outdoor temperatures.
It should be noted that sizing an air source heat pump is
always a compromise between covering coldest-day heat load
and minimizing cycling due to over-capacity in warm weather.
In cooling dominant climates, the heat pump should be
similarly sized, by matching the calculated cooling load to the
standard capacity rating at an outdoor temperature that matches
the local maximum outdoor temperature. The difference here is
that it is necessary to cover all of the cooling load, since there is
no backup cooling.
Even in northern heating dominant climates, it should
be ensured that 100% of the cooling load will be covered
when sizing the heat pump.
Heat Pump Sizing
TABLE 1 contains a guideline to the size of home each
air source heat pump size can handle.
TABLE 1 - Heat Pump Size vs. Heated Area
Model sq.ft. m
2
45 1,400 130
55 2,000 185
65 2,600 240
75 3,100 290
TABLE 2 - Plenum Heater Sizing
Model
Plenum Heater Size (kW)
Recommended Internally 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
Two styles of plenum heater are available; the first is for
internal installation (inside the indoor unit). Note limit for size 45
in above table.
The second has a wider element profile for installation
outside the unit, in the ductwork. If field-installing the fan in the
convertible side discharge position, this type of plenum heater
will need to be used.