When it is needed
- Fans that run continuously, where even a modest percentage is a large annual sum
- Dampers held well below fully open to control flow
- A fan selected for a plant capacity the line never reached, or exceeded
- Motors that trip or run hot at the present duty
- An energy manager who needs a documented saving with a payback period, not a brochure
What we do
- Measure the fan as it runs: flow, pressure, speed, power, damper position, gas condition
- Establish the duty the process needs now, which is often not the duty on the nameplate
- Calculate the fan efficiency and the system efficiency at the present point
- Model the options: damper opened and speed reduced by pulley change or VFD, rotor replaced with a higher efficiency design, impeller trimmed, fan replaced
- Price each option against the measured kWh and the plant's tariff, with the payback
What you get
- An audit report with measured figures, calculated efficiencies and the saving for each option in kWh, rupees and payback months
- A ranked recommendation, which is sometimes to do nothing because the fan is already close to its best point
- A scope and quotation for the recommended work, where there is work to do
The fan laws make the case: flow follows speed, pressure follows speed squared, power follows speed cubed. A fan running at 90% speed draws about 73% of the power. That is why a damper is the most expensive way to control flow.