Customer Brief: Genesys Engineering

Genesys Engineering worked with engineers from Blue Ridge Numerics to deliver an HVAC redesign for the Yale School of Medicine.  CFdesign software was used to simulate a new design that promises not only to eliminate contaminants more effectively, but to do so with nearly half the airflow of the existing configuration.

Genesys started the project by studying the original drawings of the building, examining test and balance reports that document air quantities being delivered by the HVAC system, and reviewing control system schematics.  The research was supplemented by hours of interviews with the school’s operating staff and hundreds of hours on-site examining every aspect of the building.

Existing turbulence

Blue Ridge Numerics kicked off the analysis part of the project by taking detailed measurements of the lab room used for the redesign, capturing major features such as pendant lighting fixtures and bookshelves that affect airflow.

Genesys took the measurements and existing information on airflow rates and diffuser deflection angles and built a CAD model of the existing room in Autodesk Inventor.  The model, containing only the essential features that impact airflow and contamination removal, was meshed automatically by CFdesign to ready it for simulation.

“The CFdesign simulations proved beyond a reasonable doubt that the patterns were turbulent and not conducive to moving contaminants out of the room very effectively,” says Marty Wallace, a senior associate at Genesys. “They also validated many of the occupants’ complaints about uncomfortable drafts in certain parts of the room.”

Reduced energy, better contaminant removal

Genesys provided Blue Ridge with a modified diffuser layout that would provide more uniform flow from the windows, down the bench aisles and to the fume hood and general exhausts.  Although an improvement over the existing layout, the revised design resulted in too many drafts in the room when simulated in CFdesign.  Two more diffuser locations needed to be designed and tested before determining the best design option.

The CAD model for the modified design was brought into CFdesign for testing with several air change rates, simulating heating, peak cooling and emergency flush modes.  Several chemical spill simulations were also run to find out how long it took to clear most of the vapor from the room.  

“We could not have proven our point without the simulations provided by CFdesign software,” says Wallace.  “Upfront CFD was the only way we could analyze airflow patterns with any degree of confidence, without the exorbitant expense of constructing a full-scale model of the space.”

The final design promotes laminar (smooth) flow from diffuser (inlet) to exhaust grilles, clearing chemicals, reducing drafts and resulting in much greater energy efficiency.  The CFdesign results showed conclusively that the new layout, with less airflow, cleared the room of contaminants more quickly and effectively than the original layout.