Hoval RoofVent CON-9, Design Handbook

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2.3 Operating modes
The RoofVent
®
twin pump has the following operating modes:
■ Off
■ Ventilation
■ Recirculation
■ Recirculation night
■ Exhaust air
■ Supply air
■ Night cooling summer
■ Emergency operation
The DigiNet control system regulates these operating modes automatically for
each control zone according to the scheduler. In addition, you can:
■ manually switch the operating mode of a control zone,
■ switch each individual RoofVent
®
unit to the following operating modes: Off,
Recirculation, Exhaust air or Supply air.
Code
1)
Operating mode Use Diagram Description
OFF Off
The fans are turned off. Frost protec-
tion remains active. There is no room
temperature control.
If the unit is not
needed
Supply air fan ................... Off
Exhaust air fan ................. Off
Energy recovery ............... 0 %
Fresh air damper .............. Closed
Recirculation damper ....... Open
Heating/cooling ................ Off
VE2 Ventilation
The RoofVent
®
unit blows fresh air into
the room and draws off spent room air.
Heating/cooling and energy recovery
are controlled on the basis of heating
demand and temperature conditions.
The room temperature set value day is
active.
During room use Supply air fan ................... On
Exhaust air fan ................. On
Energy recovery ............... 0 – 100 %
Fresh air damper .............. Open
Recirculation damper ....... Closed
Heating/cooling ................ 0 - 100 %
Mixed air operation
When fresh air temperatures are low, the
RoofVent
®
unit automatically switches to
mixed air operation (50 % fresh air, 50%
recirculation). The exhaust air fan works
at half the air flow rate.
Supply air fan ................... On (100 %)
Exhaust air fan ................. On (50 %)
Energy recovery ............... 100 %
Fresh air damper .............. Half open
Recirculation damper ....... Half open
Heating ............................ 100 %
Defrosting
When fresh air temperatures are very
low, condensate in the extract air may
freeze. If the pressure drop in the
plate heat exchanger is too high, the
RoofVent
®
unit switches automatically to
defrosting mode.
To defrost the plate
heat exchanger
Supply air fan ................... Off
Exhaust air fan ................. On (50 %)
Energy recovery ............... 100 %
Fresh air damper .............. Closed
Recirculation damper ....... Open
Heating ............................ 100 %
RoofVent
®
twin pump
Construction and operation