Desert Aire SelectAire Plus SP Series, Инструкция по установке и эксплуатации

Страница: 89 / 110

89
5.5.6.2 Evaporator Bypass and Thru Dampers
When the compressors are on, the evaporator air pressure differential will determine
if airflow is properly programmed in factory settings. The evaporator bypass damper
will modulate to achieve this programmed setting.
In certain modes of operation the Evaporator Thru damper will modulate. This damper will
modulate to maintain the pressure drop across the Circuit A evaporator.
5.5.6.3 Exhaust Dampers
The exhaust dampers will open and close depending on the requirement for exhaust
air. There are two types of exhaust: warm and cool. The cool exhaust damper works
in conjunction with the Evaporator Thru damper to achieve energy recovery. The
warm exhaust opens when no energy recovery is needed or a very high level of
exhaust air is required.
5.5.7 Examples of Cooling and Dehumidification Operation
The following are examples of how the unit will be expected to operate in the typical loads
encountered. Note that there are many variables in conditions and unit sizing. These are
included to give basic understanding of the expected operation.
Ambient Condition Cool and Humid (Typical Spring Day)
Unit will be primarily in dehumidification mode and may cycle in 1st and 2nd stages of
dehumidification. In hot gas reheat coil will be active most times. The unit may occasionally
shift to cooling mode on one or both circuits, especially during mid-day when the solar load is
high. During the night-time hours when the unit is unoccupied and ambient starts to cool, the
unit will be in dehumidification mode less frequently and auxiliary heating may become active.
Ambient Condition Hot and Humid (Typical Summer Day)
Unit will be primarily in dehumidification mode and cooling active. The remote condenser will
be active most times. The unit may occasionally shift to dehumidification mode on one circuit,
especially as the solar load starts to decrease in the afternoon. During the night-time hours
when the unit is unoccupied and ambient starts to cool, the unit will be in cooling mode less
frequently and more frequently in dehumidification.
Ambient Condition Hot and Dry (Typical Early Fall Day)
Unit will be primarily in cooling mode with one or two circuits active. Depending on the load
one or both of the circuits may cycle on and off to maintain condition. During the night-time
hours when the unit is unoccupied and ambient starts to cool, the unit will be in cooling mode
less frequently and auxiliary heating may become active.
Ambient Condition Cold and Dry (Typical Winter Day)
If the unit is equipped with exhaust energy recovery, and the controller senses the zone
dehumidified temperature within the space is dropping, it will shift to energy recovery mode.
Desert Aire - SP Manual