Supply air fans speed control strategies
Supply air fans speed control strategies
- AHU supply air fans should operate at full speed (1440 rpm) when
- the store requires > 50% heating or cooling
- the store requires economy cycle (first stage of cooling)
The remaining time the fan should operate at 2/3 speed control (960 rpm) when
- there is no call for heating of cooling
- there is <50% heating or cooling (between economy cycle and 50% cooling)
On average the fans will operate at low speed (960 rpm)
- Melbourne – 60%
- Sydney – 50%
- Brisbane – 40%
- Cairns – 30%
The energy saving for a 20kW fan operating at low speed will vary, but for Sydney it would be about $5,000pa.
Another consideration is that the VSD will have a life expectancy of 10-15 years, where as a two speed motor will have a life expectancy of 15 to 20 years.
Another consideration is that the VSD will have a life expectancy of 10-15 years, where as a two speed motor will have a life expectancy of 15 to 20 years.
