Energy Audit for AHU-MGCS Energy Audit Company



Technical Details of AHU

  • Double skinned type AHU with PUF (25 mm thick) are provided with EFF1 level motors.
  • Blower with paddle blade impeller are provided.
  • The belts are V-Belt.
  • Chilled water coil of copper tube with finned aluminum fins provided.
  • Chiller coils with 6 rows with 12 fins per inch spacing provided.
  • The fan is so designed with outlet velocity restriction upto maximum 10 m/sec. 50mm thick air filter with 3 ply HDPE with 2 layers of aluminum provided.
  • The ducts are of galvanized sheet with suitable insulation and support.

Layout Details

  • There are 12 nos of Air handling unit in the premises.
  • Motors are operated through Star-Delta and DOL starter.
  • There is no controlling of chilling water or other sensor to control AHU.


AHU Schematic Drawing for Energy Audit
AHU Schematic Drawing for Energy Audit


Energy Audit data for AHU
Energy Audit data for AHU



  • From Above Table, 5 out 9 AHU Specific energy consumption kW/TR is higher than design.
  • RPM of fan also has been derived through formula as it connected through V-Belt.
  • Through static pressure it can conclude there is no obstacles in return air path, G-5 & G-6 considerably on higher side.
  • Replacement of V-Belt with Flat-Belt as per below mentioned cons and pros

Disadvantage of V-Belt:

There is a power transmission loss of about 5-7%, when V-Belts “WEDGE IN” and “WEDGE OUT” of the grooved pulley.

Advantage of running in Flat Belt:

  1. Prevents elongation due to moisture absorption.
  2. Ensure Better Grip of Pulley.
  3. Energy Saving of at least 5-7%.

Energy Saving Recommendation:

Conversion of V-Belt to Flat belt in all AHU’s between Motor and Fan.

Result of the outcome:

Energy saving of at least by 5-7%

Proposed Electricity Saving

Saving Calculation:

Total Consumption in AHU = 63.05 KW

Energy Saving @ 7%              = 4.413 KW

Energy saving per annum     = 4.413 X 10 X 240 ( 10 hours ,240 days of working)

= 10592.4 kWh

Monetary Saving                   = Rs 1.18,105.2/-

Investment                             = 50,000/-

Payback                                  = 5 Months

Annual GHG Mitigation 8.78 ton of CO2

Please go ahead and get your electrical, thermal devices audited now to save on money.

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