CG-SVX039C-GB
57
Total Heat Recovery
The total heat recovery option includes:
− A Common braze plate heat exchanger for both
refrigeration circuits installed in serial between
with the compressor discharge and air-cooled
condenser, allowing mix of liquid and gas at the
outlet leaving to condenser coil.
− MCHE Condenser coil with EC fan motor only to
maintain the discharge pressure above the THR
water outlet condensing temperature.
− A 3-way modulating valve factory installed on
the water side to manage the leaving water
temperature and required high discharge
pressure.
− Two temperature sensors for inlet and outlet hot
water temperature control.
− Freeze protection heaters (option).
The heat exchanger is used both as a desuperheater and
a condenser of compressors discharge gas. Refrigerant
leaves the total heat recovery braze plates heat
exchanger as a mixture of gas and liquid. The air-cooled
condenser is used to finalize the condensation and
provide a subcooled refrigerant to the expansion valve.
Main stream of refrigerant flow in these units is through
filter drier keeping bypass opening to 10% with THR Off.
This avoid oil distillation in dead branch. During THR
operation bypass valve open 100% allowing 65% of
refrigerant flow via bypass line to maintain pressure.
The heating capacity is driven by the cooling demand on
the chiller, the ambient temperature and the temperature
of the heat recovery loop. The heating capacity is
optimized by a smart control of the condensing
temperature using the fans.
Water circulating inside the heat recovery heat
exchanger should never be used in food processing or as
drinking water. It must be used through a direct loop to
heat or preheat water.
Note: Ambient temperature shall be lower than THR
leaving water temperature set point to operate allowing
45% up to 116% evaporator heat recovery
Note: If the total heat recovery heat exchanger is
drained, the heater must be turned off to avoid
damaging the total heat recovery heat exchanger. The
heater should only be on when the heat recovery heat
exchanger has water in it.
CAUTION! Discharge gas temperature can reach 130°C,
may resulting in overheating of the heat recovery water
if there is no appropriate flow.
CAUTION! For the first start, Total Heat Recovery water
temperature sensors should be checked to make sure
that they are not reversed.
CAUTION! A field-installed safety or relief valve on the
water side is required with the total heat recovery to
prevent risks resulting from a failure of the unit control.
Piping Recommendations
A 1 to 1.6 mm strainer must be installed close to the
total heat recovery heat exchanger entering water line to
protect the heat exchanger.
Insulate water lines and other portions of the heat
recovery water loop to prevent heat loss and potential
injury due to exposure to a hot surface.
Do not use untreated or improperly treated water in the
heat recovery water loop since it will cause inefficient
operation and potential damage to the unit such as:
reduced heat transfer between water and refrigerant,
increased water pressure drop and reduced water flow.
CAUTION! : Proper Water Treatment! The use of
untreated or improperly treated water in a chiller may
result in scaling, erosion, corrosion, algae, or slime. It
is recommended that the services of a qualified water
treatment specialist be engaged to determine what
water treatment, if any, is required. Trane assumes no
responsibility for equipment failures which result from
untreated or improperly treated water, or saline or
brackish water.
Freeze Protection (Option)
The heat recovery condenser is insulated and a factory-
installed heater is installed and will protect the heat
exchanger from freezing in ambient temperatures
down to -18°C. When the ambient temperature drops
to approximately 5°C, the main controller energizes the
heaters.
Note: The inlet and outlet piping should be protected
against freezing by one of the following methods:
− Install heat tape on all field installed water
piping.
− Add freeze inhibit fluid to the total heat recovery
water loop.
CGAF CGAF CGAF CGAF CGAF CGAF CGAF CGAF CGAF CGAF
080 090 100 110 130 140 150 165 180 190
Heat Exchanger Type Stainless steel Copper Brazed plate Heat exchanger
THR Heat Exchanger model DB400
x74
DB400
x74
DB400
x90
DB400
x90
DB400
x90
DB400
x122
DB400
x122
DB400
x122
DB400
x150
DB400
x150
Water connection size (in) -
(mm)
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
3"OD –
76.1
Water content volume L 15.2 15.2 18.5 18.5 18.5 25.3 25.3 25.3 31.2 31.2
Additional Shipping Weight kg 155 155 165 165 165 210 210 210 245 265
Freeze protection – Electric heater
Max Power input (kW) 0.28 0.28 0.28 0.34 0.34 0.34 0.34 0.34 0.34 0.34
Max Amps (A) 0.7 0.7 0.7 0.85 0.85 0.85 0.85 0.85 0.85 0.85
Table 9 – General Data for Total Heat recovery (THR) Option CGAF 080-190
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