03
WHISPA III
®
5000, 9000 & 12000 RCU
1.0
2.0
3.0
4.0
1.0 Safety Instructions
2.0 Heating System Design
3.0 Selection and Sizing for Heating
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Heat output performance figures for the three sizes of
WHISPA III
®
RCU fan convectors are given in the Technical
Data section of this manual.
l
Since WHISPA III
®
RCU fan convectors are supplied with fan
speed control, it is important to size the unit to match the
calculated heat loss requirements of the room with the unit
operating at the low fan speed (I).
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The higher fan speed can then be used for more rapid
heating from cold in extreme conditions.
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When establishing the temperature difference, i.e. entering
water to room temperature, allowance should be made for
temperature drop in the system. It is the water temperature
at the fan convector that dictates the output.
4.0 Location
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The WHISPA III
®
RCU fan convector is designed for recessed
wall applications.
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WHISPA III
®
RCU fan convectors are designed for normal
2" x 4" stud wall framing, with 5/16" thick cover
extending beyond the wall surface once installed.
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The size of the opening required to be cut for installation is
shown in Fig 1.
READ THIS INSTRUCTION MANUAL THOROUGHLY BEFORE BEGINNING INSTALLATION.
This appliance is intended for indoor use only. For
your safety please install and use this unit with the
following precautions:
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This appliance must not be fitted in a bathroom or other
similar high humidity area.
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According to the National Electrical Code all electrical work
must be carried out by authorised/licensed professionals.
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To provide continued protection against electric shock,
this appliance must be grounded.
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Isolate the electrical supply before commencing any electrical
work.
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A suitable socket outlet with isolating switch must be
available, or fitted to supply the unit.
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In the event of a fault with this product, immediately isolate
from the electrical supply.
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The minimum wall cavity depth required for installation is
3
1
/
2
".
The WHISPA III
®
RCU should be used on closed circulation, two
pipe, pump assisted central heating systems or as a stand alone
zone or it can be fitted on a series loop with mono-flo or venturi
Tees.
Before proceeding with the installation, the heating system
design must be considered and the unit correctly sized to meet
the heat loss requirements of the room at normal fan speed.
For optimum fan convector performance the system must be
capable of providing sufficient water flow through the heat
exchanger. This means that:
1. Care must be taken in sizing both the pump and piping.
2. The minimum pipe size from boiler to fan convector must be
at least
1
/
2
".
3. Where the unit is fitted on to a system with other emitters a
separate circuit for the fan convector should be considered
to provide adequate water flow.
4. The system water must be above 110°F for the fan to switch
on and for satisfactory operation the mean water temperature
should be above 140°F.
5. Optimum performance of this unit will require effective
balancing of the whole system.
6. This unit should NOT be used to replace a radiator in an
existing heating system unless an adequate flow of water can
be guaranteed through the unit.
7. The loop must be pumped. WHISPA III
®
fan convectors are
not suitable for gravity circulation systems.
EN
33359 Whispa RCU (US) FR.qxp 15/04/2019 11:00 Page 4
