Inclined Batch Dryers (IBD) are widely used for drying grains after harvest in Malaysia. The drying system consists of a hot water heat exchanger (coils), a direct driven 18.5kW centrifugal fan and an Inclined Batch Drying Chamber.
Ambient air is drawn through the hot water heating coil and heated up to a temperature of about 48°C, before being supplied to the drying chamber loaded with grains.

The existing drying process takes 26 hours to achieve the required grain moisture content level.

Only the centrifugal fan is replaced with a certified performance rated unit using exactly the same driven power of 18.5kW while the rest of the components remain unchanged.
The drying time dropped from 26 hours to 16 hours to reach the required grain moisture content level.

A total of 24 units of Certified Performance Fans were retrofitted and all achieved the reduced 16 hours drying duration.

Retrofitting of 1 x 18.5kW Certified Air Flow Performance Fan each for 24 units of IBDs

Energy Savings calculation

Two harvest seasons per annum for duration of about 5 months in total per annum. Based on 1 Centrifugal Fan of 18.5kW operating 26 hours per batch drying time.

One month 30 days x 24 hours = 720 hours
One month capacity = 720 hours/26 = 27.7 batches

After retrofit, savings of 10 hours power consumption per batch drying of 18.5kW

One month savings:-
= 10 (hours) x 27.7 (batches of drying) x 18.5kW
= 5,124.5 kWh/month

Thus one year savings:-
= 5,124.5 kWhr x 5 (months)
= 25,622.5 kWh

Based on RM0.222/kWh
Total savings per annum:-
= 25,622.5 x 0.222
= RM5,688.00

Total savings of 24 units IBDs per annum:
= RM5,688.00 x 24
= RM136,512.00

Cost of one unit of new rated fan (without motor) = RM4,800.00
Therefore, return of investment (ROI) = saving/investment = RM4,800/RM5,688
= < 1.0 year