Application manual
Air quality multisensor and regulator EK-ES2-TP
Release 1.0 - Updated: 14/02/2020
Application Manual
© EKINEX S.p.A. - All rights reserved
Page 55
7.7.4.2
Delayed fan start (“hot-start”)
This function is used in case the fan forces in the room air passing through a heat exchange coil (as in the
case of the terminals to the fan-coil). In the heating mode of operation, to avoid possible discomfort caused by
the dispatch of cold air in the room, the room temperature controller does not start the fan until the fluid has
not reached a sufficiently high temperature. This situation normally occurs at the first start or after long periods
of inactivity. The function can be carried out by:
1.
a temperature control (through a temperature sensor on the coil exchange battery);
2.
a delayed start (function approximated);
In the first case the temperature of the heat conveying fluid is acquired at the exchange battery. The function
then has an effective temperature control, but for the execution is necessary that the heat exchange coil is
equipped with a sensor of minimum water temperature that acquires the temperature of the heat conveying
fluid.
The effectiveness of the function depends on a field measurement of the time actually required to have
sufficiently warm air from the terminal.
7.7.4.3
Antistratification function
This function is used in the case of heating systems with thermal exchange of convective type for rooms with
height and volume much higher than usual (atriums, fitness facility, commercial buildings, etc.). Because of
the natural convection - with warm air rising to the highest altitudes of the room - the phenomenon of air
stratification occurs, with energy waste and discomfort for the occupants at the same time. The function
opposes to the air stratification, forcing the warm air downwards.
The antistratification function requires:
rooms of great height;
availability of ventilation devices able to force the air movement downwards (opposed to the natural
convective movement of warm air);
measuring of the temperature at two heights through the installation of a second temperature sensor
at an adequate height in order to measure the actual air stratification (the main room temperature
controller is supposed to be installed at 1.5 m).
For rooms with ordinary height (2,70 ÷ 3,00 m) the DIN 1946 standard recommends not to exceed 2 K/m in
order to have an adequate comfort; this gradient may be bigger in higher rooms.
7.7.4.4
2-stage configuration with fan-coils as auxiliary stage
The fan-coil units may be used both as a main stage and secondary stage. As main stage they can be
combined only to radiators as auxiliary stage. If, however, the main stage is done with (floor or ceiling) radiant
panels, the fan-coils can be used as auxiliary stage. In the latter case they work in automatic mode with a
configurable offset with respect to the temperature setpoint for the main stage, and then carry out their
compensation function while the main stage is brought in temperature with bigger inertia.
The
Ventilation
folder, that is unique, configures a main or a auxiliary stage depending on the settings choosed
in the
Heating
and
Cooling
folders. Similarly, the display interface will act on manual / automatic and manual
forcing of the only fan-coil.
A particular case occurs when a fan-coil unit works in a season as auxiliary stage and in the other one as main
stage. It is for example the case of:
a radiant panels system that works only for heating and has a fan-coil as auxiliary stage; the same
fan-coil works as main stage for cooling;