Project Snapshot: Lab Exhaust Energy Recovery Systems | Mass General Hospital CNY149

Project Name: Mass General Hospital CNY149
Architects: Chan Krieger NBBJ
Engineer: Thompson Consultants Inc.
Contractor: JC Cannistraro Inc.
Manufacturer: Air Enterprises, Thermotech, Strobic Air
Size: 320,000 CFM Lab Energy Recovery Unit
DAC Contact: Rick McGinley


Project Overview:

MGH - Aerial PhotoMass General Hospital CNY149 is an extremely large energy recovery system.   The system includes Air Enterprises Custom Air Handling Units,  Thermotech Energy Recovery Wheels and Strobic Air High Plume Dilution Fans (Tri-Stack Fans).  The system was designed to replace individual fan sets that served separate hoods in all lab spaces.  Massive duct sections were provided to allow for combining all exhausts. It also served general lab exhaust. 

Project Challenge:

Energy Recovery Device Selection:   Selecting the right energy recovery device for the application was a challenge.  Energy Recovery Wheels were of course the desired choice.  They are much more efficient and transfer both sensible and latent energy.  They save both heating and cooling energy costs.  The Energy Recovery Wheel Savings Analysis showed an expected annual savings of $767,253 ($2.4 per CFM). 

Because some of the exhaust air was from fume hoods the building owner was concerned about cross contamination.  In order to verify that energy recovery wheels could be used,  the hospital requested a carryover assessment study. The study assumed the worst case spill for the facility with a variety of chemicals.  The theoretical carry over amounts were compared with NIOSH Threshold Limit Values (TLV).  In all cases carryover amounts were significantly below the NIOSH TLV.  Wheels were also tested after installation with SF6 gas. 


There are 4 energy recovery wheels used on this project.  Each handles 80,000 CFM and   is over 18 feet in diameter.  At the time of install they were the largest wheels used in North America.  The specification included the following:  “The structural frame and casing shall be designed and manufactured so as to allow a maximum rotor deflection of 1/32 inch, as measured at the outer radius, during maximum rated airflow condition.”  The installed wheels meet the required deflection specification.





For more information on this application; 

Related Blog Posts:
Ask Rick: Energy Recovery Wheels on Laboratory Fume Hood Exhaust?
Energy Recovery Wheels | Understanding Cross Contamination / Leakage

Related Materials:  
In the Air, Volume1

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