LX Series Unit Ventilator Controller User's Guide
45
Heating States
The Unit Ventilator Controller controls the following heating types:
•
digital heating
•
staged digital heating
•
heat pump heating
•
floating valve heating
•
modulated valve heating
The Unit Ventilator Controller turns the heating outputs ON when the following
conditions are present:
•
Fan speeds 1, 2, or 3 are ON, or fan speed modulation is at the minimum speed.
•
Permit valve radiation heating
and/or
Permit local radiation heating options
are selected.
•
All cooling outputs must be OFF for the period of time defined as a Change
Over Delay on the Heating Cooling Configuration screen, unless another input
is configured as a reversing valve. If another input is configured as a reversing
valve, the first stage of cooling turns ON at the same time as the reversing
valve. See the
Note:
You can also use cooling outputs to dehumidify. In this situation, you can
enable both cooling and heating outputs at the same time. The option to
disable dehumidification in heating mode was designed to avoid this
situation by keeping the cooling outputs OFF for dehumidifying in heating
mode.
•
The network variable nviApplicMode must be set to HVAC_AUTO or
HVAC_HEAT.
•
The UVC must receive the space temperature or it must be slaved to another
unit through nviSlave. Space temperature can be received through a hardware
input or through nviSpaceTemp.
•
There must be heating demand. See the following
•
If a floating heating valve is used, one output must open the heating valve and
another output must close the valve.
The water source used for the heating coils must be hot for the following control
outputs to work:
•
HEAT_COOL_VALVE_ON_OFF
•
HEAT_COOL_VALVE_OPEN
•
HEAT_COOL_VALVE_CLOSE
•
HEAT_COOL_VALVE_MOD
The water is considered hot when the water temperature is warmer than the room
temperature, or when nviHotWater receives a value and states different from zero.
