CLIVET ELFOFresh2 CPAN-U 70-120 Series - Definition of the rooms distribution system; The air distribution in ELFOAir is a manifold system...; Flexible ducts that are used by the ELFOAir system...; Inspection of the systems pressure drops

BT15B012GB-00 ELFOFresh² 29
Reading of graphics about ELFOFresh
2
operation and performances criteria
The graphic refers to size 300 and to standard set-point for a residential application and represents the trend of three variables at the fresh air temperature
changing:
A. COP/EER of the unit
B. Set-point temperature
C. Supply air temperature in the room
The variation of the air supply temperature in the room is usefull to understand the unit operating.
In the rst stretch from –15°C to –5°C in heating the return temperature is mainteined to a comfort value (in the example 17°C) by the modulation of the
return airow in the room.
To maintain the nominal air renewal it is possible to use the pre-heating modulating electrical heater option in duct. In the stretch from –5°C to +13°C, where
the unit operates with a nominal airow and with the compressor still operating, the supply air temperature increases at the outside temperatureincreasing.
Typically in the range of temperatures between+13°C and +20°C the compressor operates in an on-o operating (satised thermoregulation) and the actual
supply temperature is represented by the broken line that is the average between the one that occurs when the compressor is on and the one when the
compressor is o that is equal to outdoor temperature(the unit operates automatically in ventilation only).
In the stretch from 20°C to 24°C, assuming an ambient set-point higher than the outdoor temperature, the compressor is always o and the unit operates
in FREE-COOLING, i.e. in ventilation only.
In this operating mode the “COP” is maximum, in fact the only power input is that of EC fans and the input, although low, increases with the increasing of
the temperature dierence between outdoor and indoor.
In the next stretch from 24°C to 30°C the compressor is activated in cooling and the supply temperature is around 13-17°C to satisfy the thermoregulation.
In general, the ELFOFresh
2
in cooling will adjust the fan speed whenever is necessary to decrease the humidity level in the room, according to the set value.
This behaviour is shown in the example from 30°C to 38°C with an inner set of 26°C with 50% of humidity. At 38°C outside the ELFOFresh
2
maintains in
supply a specic humidity of 10,5 g/kg with a ow reduction of 50% from nominal 300 mch to 150.