21
Units taken out of service must be protected against freezing by draining water from all parts of the unit. Residual water from the exchanger can
be expelled with compressed air.
When starting the unit at an outdoor air temperature below +5 ° C, the active fluid supply to the heater must be opened before starting the fan,
which must have the projected temperature at the heating water supply to the heater. I.e. the boiler circuit must be in operation, the boiler must
heat and provide the warm water to the system.
The water heater heating system of outdoor variant units is recommended to fill with the anti-freeze mixture.
5.2.5 WATER COOLER CONNECTION
A unit equipped with a water cooler (DCC unit code) is connected to the cooling medium by means of a three - way mixing unit (see "Types of
ESUCH control units"). The water cooler outlets are located on the front or top part of the unit and are threaded. The exchanger must be
connected in counter-current to the flow of air passing through (in concurrent connection, the exchanger loses approx. 25 % of its output).
When tightening the heat exchanger connections, it is necessary, for example, to hold the heat exchanger neck with a second wrench so that
the tightening torque is not transmitted to the heat exchanger body.
Table of dimensions of water cooler connection sockets:
For the correct connection of cooling water, the direction of water flow is indicated on the casing of the unit by auxiliary labels (the exchanger must be
connected in counter-current):
cooling
water
inlet
cooling
water
outlet
air flow
direction
air flow
direction
cooling
water
inlet
cooling
water
outlet
For the water cooler to function properly, the cooler must be vented after connecting and filling the system with cooling water. The vent screws
are located directly at the heat exchanger connection necks. The vent screws are accessible either from the unit outer side or upon opening of the
unit operation doors
– see previous section.
Before starting service work on the heat exchanger (when replacing it), it is necessary to drain the heating water distribution system connected to
the heat exchanger and drain the heat exchanger itself using the drain screws on the heat exchanger collectors. The heat exchanger can then be
disconnected from the cooling water distribution system
and removed from the unit.
Max. operating water pressure of water coolers:
1.6 MPa
Size unit
heater/cooler type
thread
500
IKW-DUOVENT
®
500 DCC
G1/2"
800
IKW-DUOVENT
®
800 DCC
G3/4"
1200
IKW-DUOVENT
®
1200 DCC
G3/4"
1800
IKW-DUOVENT
®
1800 DCC
G3/4"
3000
IKW-DUOVENT
®
3000 DCC
G1"
4200
IKW-DUOVENT
®
4200 DCC
G1.1/4"
5100
IKW-DUOVENT
®
5100 DCC
G1.1/4"
6000
IKW-DUOVENT
®
6000 DCC
G1.1/4"
6900
IKW-DUOVENT
®
6900 DCC
G1.1/4"
!
For unit variants with water bivalence and heat pump (marked DXr DCA or DXr DCB in the unit code), it is recommended to use an antifreeze mixture of water
and ethylene glycol (eg. FRITERM E Stabil) in min. concentration 1:2 (i.e. 1 part of FRITERM E Stabil: 2 pats of water). If the antifreeze mixture cannot be
used, a year-round supply of heating water must be provided in front of the water heater control valve so that all frost protection functions are active. For units
that are not equipped with a Digireg
®
control system, it is recommended to install a capillary antifreeze thermostat behind the water heater
in the direction of air flow, which activates the antifreeze protection functions of the water heater in the customer control system of the unit.
Ventilation unit with heat recovery
DUOVENT
®
COMPACT DV
