Heat recovery unit RDKS - Technical manual
3
FläktGroup DC_9295GB_20190326_R5
We reserve the right to make changes without prior notice
OPERATION AND MAINTENANCE – FUNCTIONS, SYSTEM DESIGN, ELECTRICAL DATA, ENERGY CLASS
THE UNIT’S MAIN COMPONENTS
8
2
6, 10
5
4
1
3
12
13
11
7
9
1. Outdoor air sensor
2. Extract air sensor
3. Supply air sensor
4. Preheater
5. Extract air fan
6. Heat exchanger
7. Supply air filter
8. Control unit
9. Casing
10. Heat exchanger motor
11. Extract air filter
12. Postheater
13. Supply air fan
FANS
The fans are powered by energy-efficient EC motors. They are easy to
remove for service and maintenance. The speed of the fans can be ad-
justed independently of each other.
HEAT RECOVERY AND SUPPLEMENTARY HEATING
In climates where the temperature seldom drops below -10 °C, there is
usually no need for supplementary heating. This is because the rotary
heat exchanger recovers enough thermal energy from the extract air (
≤
85% h
temp
).
When the outdoor temperature is below -10 °C and the desired supply
air temperature cannot be achieved, a postheater is required, which is
controlled to maintain the set supply air temperature. In very cold are-
as, the unit can also be supplemented with a heater that preheats the
outdoor air. This heater starts preheating the air when the outdoor
temperature falls below -12 °C.
The electric heaters have an integrated overheating protection function.
NOTE! THE ELECTRIC POSTHEATER IS ONLY ACTIVATED IF THE
IMPELLER IS IN OPERATION.
FILTER
As standard the unit is fitted with a class (M5) ISO Coarse 85% bag fil-
ter. For filter replacement, see page 11.
DEFROSTING
During cold periods, when frost may form in the impeller, the integrat-
ed control unit automatically activates a defrosting function. The unit
defrosts for 15 minutes every 6 hours if the outdoor temperature is
below -10 °C. The supply air fan stops and the impeller moves forward
in sections.
COOLING RECOVERY
In the summer, if the extract air is cooler than the outdoor air, the rota-
ry heat exchanger starts to recover cooling from the cooler extract air.
This primarily applies if there is some type of cooling appliance in the
house.
ALARMS
The ISYteq Basic control panel (accessory) has a limited alarm
indicator function. The panel indicates, for instance, when there is a
temperature alarm or when the filter needs replacing.
If the ISYteq Touch 3.5 control panel (accessory) is used, the alarm will
be presented in plain text (see separate instructions).
MOISTURE CONTROL (OPTIONAL)
This function automatically limits the rotary heat exchanger’s moisture
recovery at high indoor humidity levels. This function can also be or-
dered retrospectively to supplement the unit.
CO
2
CONTROL (OPTIONAL)
This function regulates towards a preset setpoint. The fan speed is
automatically adjusted to achieve the desired CO
2
level.
NOTE! CO
2
control requires a ISYteq Touch 3.5 control panel. This func-
tion can also be ordered retrospectively to supplement the unit.
ETHERNET CONNECTION (OPTIONAL)
This function can be used to connect the unit to an existing network.
In that case, the unit is equipped with an integrated web server, which
makes it possible to read and change certain parameters via a web
browser. The connection can also be used for connection to a superior
system via Modbus TCP/IP.
To optimize the performance of communication, please follow the rec-
ommendations below.
- Minimize the number of general broadcasts.
- Only send dedicated traffic to the controller.
- Do not attempt to access the web server when using Modbus TCP-IP.
- Maximum of one Modbus message per second is recommended.
Avoid data bursts.
- Only write to Modbus registers when values have been changed.
ELECTRICAL DATA
Voltage: 230V, single phase, 50 Hz
Code
Fan motors
Rated output, W
Preheater
Electr., W
Postheater
Electr., W
Rated output
Electr., W
1)
Rated output
with cooker hood
RDKS
2 x 83
500
500
1170
1210
1)
Rated output applies when both the preheating and the postheating devices are
installed.
ENERGY CLASS
Compliant with energy class A+ in cold climate conditions (Scandinavia).
If configured for on-demand control, the unit is compliant with energy
class A in average climate conditions (Central Europe). Ecodesign
Directive 1254/2014.
