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MOHAWK COLLEGE: INSTITUTIONAL AHU BIOSCRUB PROJECT WITH M&V

A Measurement and Verification analysis was performed on 3 AHUs serving the administration, theatre and common spaces of the Campus C-Wing located at 135 Fennell Ave. W., Hamilton, Ontario. The purpose of the analysis was to baseline the AHUs pre BioScrub Coil cleaning and validate the benefits of the BioScrub post cleaning that was performed in June, 2018.

Methodology

BioScrub Coil Cleaning

All Coils were cleaned on the exterior (air side) following the procedure below:

  • Step 1: Application of BioScrub probiotic solution on Coil’s face whilst the fan is operational which allows for better penetration in Coil.
  • Step 2: Rinse BioScrub solution utilizing high pressure superheated steam applied to Coil’s face.
  • Step 3: Secondary BioScrub treatment on Coil’s face to ensure complete removal of biofilm.
  • Step 4: Final rinse of BioScrub solution utilizing high pressure supersaturated steam applied to Coil’s face.

 

Measurement and Verification (M&V)

The M&V was performed in accordance with IPMVP Protocol Option B Retrofit Isolation with the measurement of all key parameters. The M&V included an analysis on four (4) different data points:

Air Side Analysis:

  • Air Flow after the Coil
  • Temperature before and after the Coil
  • Fan Energy Consumption

Water Side Analysis:

  • Chilled Water Supply and Return Temperature

Conclusion

The Measurement and Verification on the 3 AHUs identified the following results:

Air Side Improvements:

  • Airflow across Coil improved by an average of 69%
  • Unchanged Power Consumption on the Fan

Delivered Capacity Improvements:

  • Delivered capacity improved by an average of 4.85%

Water Side Improvements: (DS1)

  • Coil Approach Temperature reduced by 57.5%

Energy Consumption Reduction: (CS2)

  • Energy Consumption Reduction of 8.9%

 
Overall benefits related to BioScrub cleaning of the Coils included:
 

  • Improved Flow Consistency across Coil
  • Increased average Cooling Capacity across Coil
  • Reduced approach Temperature on Coil
  • Little to no effect on Fan Power
  • Reduced Fan Energy Consumption
  • Supply Temperatures that can reach setpoint faster
  • Supply Temperatures that can be easily maintained across Coils

Additionally cleaning discovered the presence of cracks and leakage on some areas of the AHU housing, highlighting the importance of the need for regular inspection and maintenance on AHU housings. Buildup of dirt and biofilm can contribute to issues with AHU condition and can also hide issues such as air infiltration. This can ultimately affect overall Unit performance.
 
It can be concluded that BioScrub cleaning and having a leak detection and sealing protocol in place post cleaning will improve the overall condition of the Units and ensure they run more efficiently and at an affordable cost.