Modes Of Operation - Fantech SHR450 Manuel D'installation

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Modes of operation

1. Continuous / Ventilation Mode
In this mode of operation both fans are operating and exchanging air with the outside. The
heat recovery ventilator (HRV) constantly exchanges the air at the rate you select, either
at low or medium speed, and switches to high speed when activated by an optional remote
control. The "Low (reduced)" and "High (Normal)" fan speed selection will cause the unit
to operate in continuous exchange mode at a reduced exchange rate. Continuous mode
is recommended, since pollutants are slowly but constantly being generated in a building.
2. Intermittent / Standby Mode
The system is always on standby and operates at high speed when activated by an
optional remote control (required): "Standby" should be selected if the user wishes to
stop the unit from continuous exchange.
3a. Defrost by evacuation
A preset defrost sequence is activated at an outdoor air temperature of 23ºF (-5ºC) and
lower.
During the defrost sequence, the supply blower shuts down & the exhaust blower continues
to ventilate for a preset time. The unit then returns to normal operation, and continues the
cycle.
3b. Defrost by recirculation (only available with BPM module)
A preset defrost sequence is activated at an outdoor air temperature of -23ºF (-5ºC)
and lower.
During the defrost sequence, the motorized damper in the bypass module (BPM)
temporarily blocks the incoming fresh air stream so that the warm air from the room can
circulate through the HRV. The exhaust blower shuts down and the supply blower
switches into high speed to maximize the effectiveness of the defrost strategy. During
this cycle, the unit will not create a negative pressure. Please note that these systems
are configured to defrost with the BPM devices installed on the fresh air from outside
port. Alternate configuration are available by contacting our technical support department.
Stale Air
to Outside
Recirculate Air from Inside
Stale Air
from Inside
Supply air
to building