HVAC APPLICATIONS
HVAC APPLICATIONS
Ekinex devices
A) Time / astronomical digital switch EK-TM1-TP
B) GPS module EK-GPS-1
C) Room thermostat EK-EP2-TP
D) Actuator-controller for fan-coils EK-HA1-TP
E) NTC temperature sensor (contact) EK-STC-10K-3435
F) NTC temperature sensor (immersion) EK-STI-10K-3435
Other system components
1) Fan-coils units
2) Valve with ON / OFF servomotor
3) Heat exchange battery
4) Fan group
5) Contact for condensate drip tray
6) Window contact
7) Thermal generator (warm fluid)
8) Thermal generator (cold fluid)
9) Boiler room manifold (flow)
10) Boiler room manifold (return)
Fan-coils are terminal units that are widely used in offices, shopping centres, hotels and
hospitals and, in general, in medium-large buildings.
Fan-coils are used in hydronic systems for room heating and cooling, using small
terminals for convection heat exchange (with prevailing forced effect). One or two
batteries for water-air heat exchange, a fan unit and the actuating devices (2 or 3-way
valves with electrothermal actuators or servomotors) to regulate the flow rate of the
heat transfer fluid to the exchange battery provide for this. Some versions can be
equipped with an auxiliary heating battery powered by electricity.
In addition to the units with the traditional 3-speed fans, there are also versions with
brushless motor and inverter board that allow a continuous control of the fan speed by
means of a 0-10V control voltage.
From a construction point of view, the fan-coil units can have different shapes, such
as cabinets for ceiling or wall mounting; the ceiling versions can be stand-alone or
connected to air ducts installed in the plenum.
Control with Ekinex
The application examples show two different and very common system configurations.
In the first case (example I), the fan-coils (1) are equipped with a 3-speed fan unit
and connected to a 2-pipe heat transfer fluid distribution system. In the heat exchange
battery (3), warm or cold fluid circulates alternately and the flow is controlled by the
valve (2).
The room air temperature is controlled by room thermostats EK-EP2-TP (C) and
actuator-controllers for fan-coils EK-HA1-TP (D). The room thermostats (C) are
connected to the window contacts (6) and contact temperature sensor EK-STC-
10K-3435 (E), while the actuators (D) are connected to condensate drip tray contacts
(5) and immersion temperature sensors EK-STI-10K-3435 (F) installed on the inflow
pipe of the heat transfer fluid.
In this application, the switchover between heating and cooling can be carried out
automatically, by measuring the temperature of the fluid arriving from the distribution
by means of an immersion temperature sensor (F) connected to an actuator input (D).
Alternatively, Ekinex® devices can receive the switching control via bus (centralised
manual switching mode).
Fan-coil systems
2
1
3
4
5
IN1
4
3
C
1
1
2
1
V1
V2
3
1
4
1
V3
5
1
6
1
DO1
7
1
8
1
IN2
7
8
5
6
9
0
1
1
2
L
N
Dev.
Line
Area
bus KNX
230Vac-50/60Hz
R
EK-HA1-TP
Fan-coil actuator/controller
6
9
10
7
8
T
2
1
3
4
5
IN1
4
3
C
1
1
2
1
V1
V2
3
1
4
1
V3
5
1
6
1
DO1
7
1
8
1
IN2
7
8
5
6
9
0
1
1
2
L
N
Dev.
Line
Area
bus KNX
230Vac-50/60Hz
R
EK-HA1-TP
Fan-coil actuator/controller
6
T
EK-TM1-TP
Digital time / Astronomical switch
A
B
C
C
D
D
E
E
Zone 1
Zone 2
T
T
F
F
Boiler room
Example I (2-pipe distribution)
2
1
6
7
EK-TM1-TP
Digital time / Astronomical switch
A
B
C
D
IN1
4
3
C
1
1
2
1
V1
V2
3
1
4
1
V3
5
1
6
1
DO1
7
1
8
1
DO2
IN2
6
5
IN3
8
7
0-10V
9
0
1
1
2
L
N
Dev.
Line
Area
bus KNX
-
+
230Vac-50/60Hz
3
1
R
DO1
2
DO2
EK-HC1-TP
Fan-coil actuator/controller
3
4
5
T
E
8
9
Room or zone
F
Boiler room
Example II (4-pipe distribution)
In the second case (example II), the fan-coils (1) are equipped with two heat
exchange batteries (3, 5) and a fan unit with brushless motor controlled by an inverter
board. The units are connected to a 4-pipe heat transfer fluid distribution system. With
this kind of distribution, if both fluids are available from the boiler room, there can be
heated and cooled rooms simultaneously in the same building; the flow is controlled by
two valves with ON / OFF servomotor (2, 4).
The room air temperature is controlled by room thermostats EK-EQ2-TP (C) and
actuator-controller for fan-coils EK-HC1-TP (D) which have an output with the
0-10V voltage required for a continuous control of the fan speed, obtaining all the
advantages of these terminals: more precise response to the variation of heat loads,
better temperature stability, reduced noise and high efficiency even at partial load with
a consequent reduction in electricity consumption. Temperature attenuations can be
called up automatically in the absence of people, thanks to the presence sensor EK-
DF2-TP (F).
In this application, an automatic switchover between heating and cooling, based on
measured temperature and setpoint values, can be advantageous. Alternatively, and
with both transfer fluids available, the switchover can also be performed locally on the
room thermostat in manual mode. In both cases, several utility functions for comfort,
energy efficiency and system maintenance can be added according to the needs of
customers and end-users: a few examples are given below.
Comfort
The contact temperature sensor (E) installed on the heat exchange coil allows the fan
unit (4) to be started only when the temperature of the heat transfer fluid is comfortable
for the users (warm-start function). If the sensor (E) is missing, the function can also be
performed by setting a simple start-up delay.
In rooms with big height and volume (atriums, gyms, commercial rooms), air
stratification can occur, with energy waste and discomfort for the end-users. To limit this
effect, a temperature sensor (E) is connected to the thermostat (C) and a maximum
temperature gradient is configured that must not be exceeded.
Energy saving
The window contact (6) connected to an input of room thermostat (C) automatically
switches the operating mode from comfort to building protection, avoiding the loss of
heating and cooling energy to the outside.
Maintenance
The actuator-controller (D) is provided with an operating hours counter which increases
the count when the fan unit (4) is set at least at first speed. When the set time interval
is reached, a signal is activated to replace the filter of the fan-coil unit.
Ekinex devices
A) Time / astronomical digital switch EK-TM1-TP
B) GPS module EK-GPS-1
C) Room thermostat EK-EQ2-TP
D) Actuator-controller for fan-coils EK-HC1-TP
E) NTC temperature sensor (air) EK-STL-10K-3435
F) Presence sensor EK-DF2-TP
Other system components
1) Fan-coil unit
2) Valve with ON / OFF servomotor (warm fluid)
3) Heat exchange battery (warm fluid)
4) Valve with ON / OFF servomotor (cold fluid)
5) Heat exchange battery (cold fluid)
6) Contact for condensate drip tray
7) Window contact
8) Thermal generator (warm fluid)
9) Thermal generator (cold fluid)
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