Bosch Geothermal Heat Pumps Applications Manual page 30

3 0 | Bosch Geothermal Heat Pumps
Examining the "Low Temp Heating" data for the Bosch
four (4) ton geothermal heat pump unit (Table 16), we
nd that at 30°F EFT and 70°F Entering air temperature
(return air temperature), the part load heating capacity
(compressor operating at 67% ability) of the Bosch four
(4) ton geothermal heat pump unit will be 27,770 Btu/h.
This provides approximately 43% of the structure heat
loss at design conditions. Since we will not be at heating
design conditions, the actual structure heat loss will be
lower and the compressor will likely be able to meet the
structure heating needs adequately. The supplemental
heating (electric coils) will be used to meet the portion
of structure heat loss not met by the compressor at that
condition. The heater will still provide the necessary
heating if operating in emergency heat mode (compressor
failure).
Capacity Data - Full Load Low Temp Heating
Entering Entering Total
Fluid Temp. Air Temp. Capacity
(ÝF) (ÝF) (MBtuH)
25 27.79
30 29.35
60
40 32.47
25 26.29
30 70 27.77
40 30.71
25 24.53
30 80 25.90
40 28.65
Tab. 16
(Antifreeze required)
(EFT Range (Standard) 25ÝF to 80ÝF)
In this example, a Bosch four (4) ton geothermal heat
pump unit with a two-stage compressor was selected. This
application is acceptable and the heating needs in the
colder climate may require the use of auxiliary heat below
the structure balance point, but this will be less run time
than the Bosch three (3) ton geothermal heat pump in
this situation.
Data subject to change
Power Heat of
Input Abs. COP
(kW) (MBtuH)
1.82 21.59 4.5
1.84 23.08 4.7
1.88 26.04 5.1
1.85 19.99 4.2
1.87 21.38 4.4
1.92 24.18 4.7
1.89 18.09 3.8
1.91 19.39 4.0
1.96 21.97 4.3
Applications Manual
Bosch Thermotechnology Corp.