Fantech VHR Series, Operation Manual

5

Some products may not be exactly as illustrated in the Operation Manual.

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" and "Med" fan speed selection will cause the 
unit to operate in continuous exchange mode at an exchange rate of 
35% and 50% maximum airflow rating respectively. Continuous mode is 
recommended, since pollutants are slowly but constantly being 
generated in your house.

The switch on the side of the unit is used to toggle between STANDBY, LOW speed and MEDIUM speed modes.

In order to activate HIGH speed, a jumper must be placed between the DEHUM + and DEHUM - contacts.

* no exchange of air

Air to

House

Air to 

Outside

4. Defrost/Fan shutdown (4 port models) 

The automatic defrost cycle for SHR/VHR models of HRVs consists of a 
fan shutdown. When the supply air stream temperature goes below 
-5°C (23°F), the supply fan shuts down and the exhaust fan goes into 
"High" speed. Ambient air is passed through the unit for a period of 5 
minutes. The supply fan will then re-start and run at the presetspeed. 
The exhaust fan will also slow down to the preset speed, and the unit 
will operate in the run cycle for 25 minutes. This fan shutdown defrost 
cycle continues until the supply air
stream rises above 0°C (32°F).

3.Defrost/Recirculation Mode (5 port “R” models)

The automatic defrost cycle for SHR R(D) / VHR R models of HRVs 
consists of a damper defrost which allows air to recirculate throughout 
the unit & home. When the supply air stream temperature goes below 
-5°C (23°F), the exhaust fan shuts down, the supply fan goes to "High" 
speed, and a damper closes the supply, opening a 5th collar. The 
ambient air is then recirculated through the unit & home for a period of 
5 minutes.
The unit will then resume normal operation for a time period of 25 
minutes. This damper defrost cycle continues until the supply air 
stream rises above 0°C (32°F). 

2. Intermittent / Standby Mode (SHR(D) / VHR Series of HRVs) 

The system is always on standby and operates at high speed when 
activated by an optional remote control. "Standby" should be selected if 
the user wishes to stop the unit from continuous exchange.  We 
recommend that the "Standby" mode only be used if your system is 
equipped with an optional external control, in which case, the unit would 
activate to "High" fan speed, until the control is satisfied and then return 
to "Standby" (off).

Air from 

House

Air to 

House

Air to 

Outside

Air from

House

Air from 

Outside

Air from 

House