In many accommodation facilities there are rooms, such as the restaurant, the conference
rooms or the gym, which have special needs, because their occupation is highly variable
over time: in fact, during the day there are periods in which they are poorly occupied,
or even empty, and periods in which the room is occupied by many people within a few
minutes and their stay can last for several hours. In these rooms ventilation and air
renewal are of great importance: keeping the air quality and humidity level under control
is essential to guarantee high comfort to the guests of the structure in every situation.
For these needs, manual control alone or a simple scheduling are inadequate solutions.
To ensure comfort and energy effi ciency at the same time, it is necessary to use an
“environmental” control by measuring one or more parameters and automatically adjust
the fresh air fl ow rate to be introduced into the rooms according to occupancy levels.
Control with Ekinex
The use of an EK-TM1-TP time switch (A), possibly with optional GPS module (B), makes
it possible not only to give a consensus to the operation of the ventilation within predefi ned
time slots, but also to activate the ventilation for a short period at maximum fl ow rate for
a periodic cleaning of the room air before working hours. The multisensor (C) measures
the most important environmental parameters for ventilation. The air quality is measured
as concentration of carbon dioxide (CO2) and total volatile organic compounds (TVOC);
besides these parameters, relative humidity and temperature are measured. The use of an
EK-DF2-TP presence sensor (D) is useful when a simplifi ed automatic air renewal control
is desired, by entering the design fl ow rate value when the room is occupied and ensuring
instead a minimum fl ow rate value to save energy when the room is not occupied. During
the summer season, if the outside temperature - measured with the EK-STE-10K-3435
temperature sensor (G) and acquired by the EK-CG2-TP universal interface (F) - is lower
than the inside one, it is possible to operate the ventilation during the night to cool the
rooms (free-cooling) with a minimum consumption of energy. The signal of a window
opening contact (4), detected by the interface (F), allows temporary deactivation of
ventilation and air handling to avoid wasting energy unnecessarily; reactivation occurs
automatically when the window is closed. The pushbutton (E) allows to manually force
operation if necessary: for example, activate the maximum fl ow rate (“boost” function)
or switch the system OFF.
Application example
M
1
2
EK-TM1-TP
Digital time / Astronomical switch
A
B
D
C
M
1
E
3
F
4
G
VENT
AUTO
LIGHT
VENT
BOOST
VENT
OFF
Ekinex devices
A) Time / astronomical digital switch EK-TM1-TP
B) GPS module EK-GPS-1
C) Multisensor EK-ET2-TP or EK-ES2-TP
D) Presence sensor EK-DF2-TP
E) Ekinex pushbutton (20venti series)
F) Universal interface EK-CG2-TP
G) NTC temperature sensor (external) EK-STE-10K-3435
Other components
1) KNX servomotor for dumpers (not delivered by Ekinex)
2) VAV (Variable Air Volume) box for air supply
3) VAV (Variable Air Volume) box for air extraction
4) Window contact
Ventilation and air renewal
The measured values can be sent on the bus to other KNX devices or used by the
integrated controller to control both thermo-hygrometric conditions and air quality with
a single compact device.
In special cases, such as in large or very voluminous rooms, where there is a strong
asymmetry in the temperature distribution or when the device is installed in an unsuitable
position, the room temperature can be adjusted using a weighted average of two
temperature values: the fi rst one measured by the integrated sensor and the second one
received by the KNX bus.
Two independent thresholds for relative humidity and three thresholds for air quality
can be confi gured. To implement automation logic, AND, OR, NOT and exclusive OR
logic functions are available; thanks to these, it is possible to use the information made
available by the home automation system to control the air renewal according to the
actual requirement (DCV, Demand Controlled Ventilation).
The device is also available in the EK-ET2-TP version with only CO2 concentration
measuring.
Control based on CO2 or TVOC values
The choice of the control parameter depends mainly
on the intended use of the rooms. Where the variabil-
ity in the occupancy rate is very high or unpredictable
(such as in meeting rooms, classrooms or small com-
mercial environments) CO2 is the most used indicator
because its concentration is directly related to human
activity and, in particular, to breathing. Although CO2 is
not harmful to human health (except in very high concentrations, which are diffi cult to
achieve), it has a direct impact on the concentration capacity and productivity of the oc-
cupants. When the number of people in the room is predictable and limited, the detection
of volatile organic compounds (or VOC), a set of organic chemicals continuously emitted
from furniture, paints, cleaning solvents, adhesives or other synthetic materials due to
their high volatility, may be more signifi cant.
Air quality
Whether it is a guest room, a fi tness centre or a conference room, air quality is a
prerequisite for an accommodation facility. Poor air quality, which often occurs indoors,
is caused by pollutants from both inside and outside the building and the increased
concentration of CO2 due to human presence.
Ensuring high air quality is even more important since of buildings have been built or
renovate in accordance with the legal provisions following the EPBD (2002/91/EC); in
fact, with the aim of limiting heat loss to the outside as much as possible, buildings are
now strongly insulated and equipped with airtight windows and doors. This increases
energy effi ciency, but makes buildings airtight. In these conditions, the manual opening
of windows alone seems inadequate and exposes people to risks due to the increased
concentration of pollutants emitted slowly but constantly by the synthetic products
used in the construction sector and by the consumer products present in all buildings. If
exposure to pollutants in indoor environments is prolonged over time, the problem is no
longer just one of environmental well-being, but can also seriously aff ect people’s health.
It is therefore clear why it is important to take all necessary precautions to ensure high
air quality.
Demand Controlled Ventilation (DCV)
If there is no automatic control, room ventilation can result in a signifi cant energy cost.
The control of air renewal through the building automation system makes it possible to
combine high air quality with high energy effi ciency.
Thanks to the many environmental parameters made available by the ekinex automation
system, it is possible to carry out ventilation control according to the actual need for
air renewal (a strategy known as DCV or Demand Controlled Ventilation). This allows
to constantly adjust the air fl ow rate to be introduced into the rooms to the real needs
with the aim of maintaining a constantly high air quality, while minimizing the energy
consumption.
Using Ekinex for this purpose also means containing the number of sensors to be installed
and using in a multifunctional way the devices and signal network already provided in the
building for other functions, such as air conditioning, lighting or shading control.
With this type of control, energy is saved in two ways: the operating time of the fan
units and the fl ow rate of fresh air to be treated - by heating, cooling, humidifi cation and
dehumidifi cation before being introduced into the room - are reduced.
Multisensor with controller for T - R.H. - CO2 - TVOC
The EK-ES2-TP multisensor (C) is a complete room climate control device that combines
in a single product many functions usually distributed among several diff erent sensors
and controllers. The device measures temperature, relative humidity and air quality
(parameters: CO2 equivalent concentration in ppm and/or TVOC concentration in ppb)
using the integrated sensors.
HOTEL SOLUTIONS
HOTEL SOLUTIONS
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