Fläkt Woods
8217 GB 2014.07.02 20
Specifications are subject to alteration without notice
TopMaster Air Handling unit
CONTROL AND REGULATION EQUIPMENT
1. Rotor, heating and cooling
The unit is configured differently with regard to heating,
heat recovery and cooling, see below.
Choice of heating function
• No heater
• Electric heater
• A water heater with frost-guard function
Heat recovery
• Continuously rotating heat exchangers
Choice of cooling
• No cooling
• Water -cooling
• DX cooling, 1-stage
Control function
The control function works as follows:
Regardless of control mode the unit tries to achieve the
desired setpoint.
This is done by the unit depending on the needs,
demand for heat recovery, heating or cooling. Built into
the system is also a dead zone. The dead zone function
(usually 2°C) acts as a temperature zone between heat
recovery and cooling unit where neither calls for heat re-
covery or cooling.
The reason for having a dead zone, is that the tempe-
rature will be slightly lower in winter, and slightly higher
in summer. This is energy-efficient and in practice even
more convenient for people staying in the room.
Room control and exhaust air control is the same
control type with the difference that in combination with
room control an external room sensor is needed (separate
ordering code). In addition it is possible to use outdoor
temperature compensation. This control mode cannot be
combined with extract air control or room control.
The unit is configured for supply air control as stan-
dard. To obtain other control modes, first the controller
must be changed from standard mode to cascade mode.
Then control mode is selected by changing the cascade
reference to extract air control/room control (0) or outdo-
or temperature compensation (1). Below is a description
of the different control modes.
Supply air control
To maintain a constant supply air temperature, the con-
troller works from a fixed setpoint and the supply air
temperature. Based on these parameters, the controller
controls the current heating, heat recovery and cooling
sequences.
Extract air control
The exhaust air temperature gives a good average value
of the temperature in different rooms. Using this the
unit controls the supply air temperature to maintain the
extract temperature at a desired level.
This method is suitable for ventilation systems that
supply a number of similar rooms. In cases where dif-
ferent rooms have different heating requirements, this
method should not be used. This is because the unit can-
not detect the varying heating needs, but can only read
an average temperature.
The limits on the supply air temperature (min. temp.
/ max. temp.) ensure that the supply air temperature is
maintained within the set range.
Default parameters for extract air control
1. Controller = 2
Selects cascade control
2. Cascade reference = 0 Selects extract air control
3. Cascade A = 0.5
When the sensor gets colder
than given setpoint value
4. Cascade B = –0.5
When the sensor gets hotter
than given setpoint value
5. Min. temp. = 15°C
Sets lowest supply air
temperature
6. Max. temp. = 25°C
Sets highest supply air
temperature
Example
1. Setpoint = 18°C
2. Extract air temperature = 16°C
This means that the new calculated setpoint for the
supply air controller is:
Calculated setpoint = se (setpoint – exhaust air
temperature) x cascade A = 18 + (18-16) x 0.5 = 19 ° C.
Figure 1. The figure shows the controller’s output signals to the
various unit components at different temperatures. The
figure also shows two temperatures, one for heating (T2)
and one for cooling (T3). The zone between T2 and T3 is
called the dead zone. Note that heating is activated only
when heat recovery is working at 100%.
2. Temperature controls
TopMaster has three temperature control options, supply
air, extract air control and room control.
Control functions
Heating
Recover
y
Cooling
Control signal, %
Sequence control
Temperature, °C
100
50
T0
T1
T2
T3
T4
