Flexit SPIRIT UNI 3 User manual

Installation manual
Water heating element
FLEXIT SPIRIT
110869E-08
2015-06
ART. NO.:
110863
110948

2
Water heating element installation manual
Contents
1 Technical data 3
1.1 UNI 3 3
1.2 UNI 4 3
1.3 Capacity and sound data, supply air side, UNI 3 4
1.4 Capacity and sound data, supply air side, UNI 4 4
2 Plumbing 5
2.1 Shunt valves 5
2.2 Location of the water heating element 5
2.3 Connections 6
2.4 Venting 6
2.5 Frost risk 6
2.6 Dimensions 6
3 Electrical work 7
3.1 Uni 3-4 7
3.6 Frost sensor (B5) 8
3.7 DIP switch 8
4 Maintenance 8
5 Appendix 1 8
Our products are subject to continuous development and we therefore reserve the right to make changes.
We also disclaim liability for any printing errors that may occur.
To obtain correct values, employ the Flexit
calculation application available at our home
page www.flexit.no

3
1.1 UNI 3
Water heating element art.no. 110948 has the highest
capacity of Flexit’s water heating elements. It is designed
for systems with air flow rates of more than 280 m3/h, and
where outdoor temperatures can go below -20°C.
For other conditions, use art.no 110863.
High capacity element: example 1
Air flow rate: 350 m³/h
Power consumption: 1,28kW
Temperature, incoming water °C 60 50
Temperature, outgoing water °C 36,56 35,22
Water flow l/h 44 69
Water speed m/s 0,26 0,4
Pressure drop, water side kPa 1,39 3,18
Valve presssure drop kPa 3 7,6
Capacity kW 1,28 1,28
Pipe connection thread DN15 DN15
Valve KVS 0,25 0,25
Normal capacity element: example 2
Air flow rate: 216 m³/h
Power consumption: 0,58kW
Temperature, incoming water °C 80 70 60 50
Temperature, outgoing water °C 57,64 53,3 49 44,7
Water flow l/h 23 31 47 96
Water speed m/s 0,14 0,18 0,27 0,56
Pressure drop, water side kPa 0,25 0,42 0,91 3,44
Valve presssure drop kPa 0,33 0,6 1,38 5,76
Capacity KW 0,58 0,58 0,58 1,28
Pipe connection thread DN15 DN15 DN15 DN15
Valve KVS 0,4 0,4 0,4 0,4
Normal capacity element: example 3
Air flow rate: 350 m³/h
Power consumption: 1,28kW
Temperature, incoming water °C 80 70
Temperature, outgoing water °C 66,38 63,03
Water flow l/h 84 164
Water speed m/s 0,49 0,96
Pressure drop, water side kPa 2,47 8,47
Valve presssure drop kPa 4,41 16,8
Capacity kW 1,28 1,28
Pipe connection thread DN15 DN15
Valve KVS 0,4 0,4
Water heating element installation manual
1.2 UNI 4
Air flow rate: 470 m3/h
Power consumption: 1,72kW
Temperature,
incoming water
°C 80 70 60 50
Temperature,
outgoing water
°C 41 40,4 39,73 38,98
Water flow l/h 39 52 75 138
Water speed m/s 0,23 0,3 0,44 0,81
Pressure drop, water
side
kPa 1,09 1,8 3,58 10,77
Valve presssure drop kPa 0,9 1,7 3,5 11,9
Capacity kW 1,75 1,75 1,75 1,75
Pipe connection Gjenger DN15 DN15 DN15 DN15
Valve KVS 0,4 0,4 0,4 0,4

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Water heating element installation manual
Contact resistance [Pa]
Power consumption [W]
Air flow rate [l/s]
Air flow rate [m³/h]
Water battery
Fig. 2
Yellow field:
SFP < 1.0 per fan
60dB (A) 65dB (A)
100%
100%
80%
80%
60%
60%
40%
40%
70dB (A)
75dB (A)
80dB (A)
[Pa]
0
1000 200 300 400
-10 -25 -55 -90
0
20 40 60 80
60
80
100
40
20
0
1000
200
400
100
300
500
1.3 Capacity and sound data, supply air side, UNI 3
1.4 Capacity and sound data, supply air side, UNI 4
Contact resistance [Pa]
Power consumption [W]
Air flow rate [l/s]
Air flow rate [m³/h]
Water battery
Yellow field:
SFP < 1.0 per fan
Fig. 3
65dB (A) 70dB (A)
100%
100%
80%
80%
60%
60%
40% 40%
75dB (A) 80dB (A)
85dB (A)
1000 200 300 400 500 600 700
[Pa]
-100 -25 -55 -90
100
200
75
50
25
0
175
150
125
20 40 60 80 1000 140 160 180 200120
0
200
400
100
300
500
600
700

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Water heating element installation manual
2 Plumbing
All plumbing must be carried out by an authorised plumber.
Place the unit near a gully to prevent damage in case of a
water leakage.
2.1 Shunt valves
Article no. Type
110939 2-way valve DN15 Kvs. 0,25
110940 2-way valve DN15 Kvs. 0,4
110941 3-way valve DN15 Kvs. 0,25
110942 3-way valve DN15 Kvs. 0,4
56596 Shunt valve motor
WARNING! Before commencing installation,
pull out the mains plug and wait 2 mins before
opening the door.
Fig. 5
When installing vertically, the connection pipes must face upwards.
Fig. 4:
When installing horizontally, incoming water shall be connected to the lower
pipe. Do not place the element so that both pipes appear at the bottom, or
at the top.
2.2 Location of the water heating element
NB! Please consider service accessibility before
commencing installation.
See Fig.4 and Fig. 5 for more information on element
direction.
The element must be placed with a good distance to
potential duct bends, to avoid uneven air flow above the
element.
!

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Water heating element installation manual
2.4 Venting
Remember to connect the T piece for venting, at the highest
point in the circuit.
2.5 Frost risk
A spring loaded shutting damper must be connected to
the outdoor air duct. This prevents cold air current on the
element upon system outage, which in turn might lead to
frost damages.
If antifreeze solution is not used, the element
must be placed in a heated room to avoid frost
damage.
Place the ventilation unit close to a gully, to prevent damage
in the case of water leakage.
WARNING! Make sure that everything works
correctly before using the system.
!
2.6 Dimensions
B5
Heated water
Valve
Fig. 6
Fig. 7
Pump
Place the regulation valve as close as possible to the
ventilation unit. Note that many valve motors can operate in
both directions, and that this can be controlled on the motor
itself. Adjust it so that the valve opens on a rising 0-10V
signal.
Upon connecting to the pipe system, the follwoing points
must be considered:
1. The connection pipes must not be subjected to torsion
or bending.
2. Ensure that neither expansion forces in the system nor
the weight of the system itself strain the connections.
3. Check the system for potential leakage after filling it with
water.
2.3 Connections
Employ the recommended connections (se Fig. 6) unless
otherwise stated.
Water battery
in supply air duct
205350
205
Ø160
UNI 3 - UNI 4

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Water heating element installation manual
3 Electrical work
3.1 Uni 3-4
For connection info on frost sensor (B5), valve motor
and shutting damper, refer to the wiring diagram under
section 5.
1
2Place the sensor in the supply air duct (refer to label on
top of the ventilation unit), approximately 1m away from
the the heating element. Unroll the wire on the top of the
ventilation unit, close to the supply air duct. Drill a 7mm
hole in the duct, for the sensor. Enter the sensor into the
hole, seal the hole and attach the wire to the duct using
tape.
Remove the cover for the electrical room. Connect the new cable to the central unit.
Remove the connector (2) from the cable harness (1).
Install bracket with terminal block.
5
14
2
3
OBS! Temperature sensor B1 must be placed
after the heating element.

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Water heating element installation manual
4 Maintenance
The lamellas in the heating element must be cleaned on
a regular basis. First, clean the entry side of the element
with a brush, then the whole element can be cleaned with
compressed air, water or steam.
Blow the filth away from the outgoing end to the incoming
end.
With the use of detergent, first make sure that it does not
react with copper or aluminium.
Take care not to harm the thin lamellas during cleaning.
5 Appendix 1
Attach the sensor with isolation and strips (see Fig. 8).
3.3 DIP switch
Finally, the central unit must be set to work with the water
heating element. Set DIP switch no 1 on the central unit to
position ON (see Fig. 9).
3.2 Frost sensor (B5)
WARNING! To prevent the element from fre-
ezing, a sensor (B5) must be attached to the
water pipe for outgoing water.
!
Fig. 9
WARNING! Make sure that everything works
correctly before using the system.
!
Fig. 8

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