HVAC APPLICATIONS
HVAC APPLICATIONS
The ceiling radiant system is a hydronic system for room heating and cooling, which
was added to the floor version over time; in common it maintains the characteristic
of having a low temperature difference between the heat transfer fluid and the room
air. The heat transfer fluid circulates inside circuits made up of metal or plastic pipes
integrated in a suspended false ceiling; the series of panels are fed by distribution
manifolds installed above the circuits served. In residential applications, the false ceiling
has a plasterboard finish towards the rooms, suitable for civil buildings, and an insulation
layer towards the top. The system is invisible and uses the whole surface of the ceiling
as a large terminal for the thermal exchange prevailing at radiation. As in the case of the
floor radiant system, the ceiling radiant panels only handle the heat loads of a sensible
type; in general, the ceiling solution offers a higher yield in cooling.
The radiant ceiling system shown in the example is used to heat and cool the rooms
of a residential building. This particular system is a combined system; it combines the
ceiling radiant panels with one or more units for energy recovery ventilation (ERV),
whose basic function is the renewal of the room air with high efficiency heat recovery.
In this case, moreover, they are complete machines for the air handling of the rooms,
able to support the operation of the system in summer cooling, also performing the
functions of dehumidification (with reduction of the cooling latent load) and handling of
part of the sensible cooling load.
Usually these machines do not serve a single room, but several rooms or an area of
a building. In the residential sector, for example, it is common to use one machine for
the living zone and a second one for the night zone. The installation is typically made
in a central position with respect to the served zone, for example recessed in the false
ceiling in the hallway or in the corridor.
Control with Ekinex
The EK-TM1-TP time / astronomical digital switch (A) ensures that the system is allowed
to operate according to predefined time scheduling and is constantly synchronised with
date and time by the GPS module (optional) EK-GPS-1 (B).
The room thermostat EK-EQ2-TP (E) measures temperature and relative humidity and
is installed in a position exposed to the air flow generated by the machine (1). In heating
or cooling mode, at the request of the thermostat, the actuator-controller EK-HE1-TP
(D) controls the opening of the zone valve (8) of the radiant ceiling. If necessary, an
additional NTC temperature sensor (F) can be connected to the room thermostat (E)
to carry out adjustment based on a weighted average temperature value.
At the seasonal switchover to cooling mode, the actuator-controller (D) closes the
seasonal valve (5) to avoid feeding the towel warmers with cold heat transfer fluid.
The contacts for the start / stop of the cooling integration (2) and dehumidification (3)
are activated by the binary output EK-FE1-TP (C). Cooling integration is activated when
the temperature measured by the room thermostat (E) exceeds the setpoint value by
a predefined offset value (for example: 1.5 °C). Dehumidification is activated when the
relative humidity measured by the room thermostat (E) exceeds the threshold value
predefined in the system design (for example: 50%).
A sensor (10) to detect the formation of condensation during cooling operation can be
connected to the room thermostat (E). This optimization makes it possible to increase
the operational safety of the system, closing the circuits involved by means of the
zone valve (8) if the thermohygrometric conditions should cause the beginning of
condensation on the cooled surfaces.
The optional Delégo supervision (not shown in the diagram) allows you to monitor and
control the entire home automation system through an App for smartphones.
Ceiling radiant system in residential buildings
EK-TM1-TP
Digital time / Astronomical switch
A
B
Dev.
Line
Area
bus KNX
1A
3
4
1
2
7
8
5
6
1B
2A
2B
3A
1
1
2
1
9
0
1
3B
4A
4B
L
N
5
1
6
1
3
1
4
1
L
N
N
N
C
1B
2B
3B
4B
1A
2A
3A
4A
EK-FE1-TP
8xD.O. 16(10)A/230Vac ~ 50/60 Hz
4xBlind 16(10)A/230Vac ~ 50/60 Hz
3
4
1A
5
6
2A
7
8
3A
9
10
4A
11
12
1B
13
14
2B
15
16
3B
17
18
4B
1
2
L
N
bus KNX
Dev.
Line
Area
D
E
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
T
F
Boiler room
Dehumidification
and cooling
integration
Radiant heating
and cooling
Bathroom
Example
Ekinex devices
A) Time / astronomical digital switch EK-TM1-TP
B) GPS module EK-GPS-1
C) Binary output EK-FE1-TP
D) Actuator-controller for electrothermal drives EK-HE1-TP
E) Room thermostat EK-EQ2-TP
F) NTC temperature sensor (air) EK-STL-10K-3435
Other system components
1) Energy recovery ventilation (ERV) unit with dehumidification and cooling integration
2) Contact for dehumidification start / stop
3) Contact for cooling integration start / stop
4) Valve with ON / OFF servomotor
5) Seasonal valve with ON / OFF servomotor (towel warmer)
6) Towel warmer
7) Circolating pump
8) Zone valve (ceiling radiant system) with ON / OFF servomotor
9) Distribution manifold for radiant ceiling circuits
10) Condensation sensor
11) Ceiling radiant system panels (series)
12) Thermal generator (warm fluid)
13) Thermal generator (cold fluid)
14) Boiler room manifold (flow)
15) Boiler room manifold (return)
Using configurable inputs
Thanks to the two configurable inputs of the device,
the thermostat allows additional functions to be
carried out that can increase comfort and energy
saving, without the need for additional input bus
devices. If configured as analogue, to the input is
only allowed the connection of a NTC temperature
sensor with characteristic resistance value 10 kΩ at
25°C, ß = 3435 (Ekinex® codes EK-STx-10K-3435
with x = E, I, C, L).
Input confi guration
Predefi ned applications
Digital [DI]
window contact
card holder contact
condensation sensor
Analogue [AI]
heat exchange battery temperature sensor
room temperature sensor
stratification temperature sensor
floor surface temperature sensor
outside temperature sensor
NTC generic temperature sensor
Focus on the EK-EQ2-TP thermostat
The Ekinex® room thermostat EK-EQ2-TP (E) allows the measurement of the
temperature and relative humidity of the room air mass by means of integrated sensors
with the possibility of sending values on the KNX bus. The relative humidity measurement
significantly expands the room air conditioning functions and increases the comfort and
safety of the room. Thanks to the calculation of the dew temperature, it is possible to
carry out active strategies to protect against the formation of condensation when using
radiant panel systems for summer cooling. In combination with the Ekinex® actuators-
controllers for HVAC functions, the device allows a complete independent climatization
for each room or zone, adding to the function of controller for heating and cooling the
possibility to effectively control the dehumidification and humidification of the rooms.
The display also allows you to view a series of information such as:
- temperature (measured and setpoint in °C o °F);
- relative humidity (measured and setpoint in %);
- CO2 concentration (received by the KNX bus in ‰);
- perceived temperature (calcolated according to the Humidex index in °C);
- outdoor temperature (received by the KNX bus or a NTC sensor in °C o °F).
NTC sensor
Potential-free
contact
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