Sunday, April 18, 2010

Meselson Lab Commissioning

On Friday, we visited the Meselson Lab in the Biological Labs Building at Harvard University as part of the commissioning process. The space's renovation is nearing completion and the Office for Sustainability team was there to functionally test some of the equipment. We verified that the fan coil units (FCUs) and baseboard heating responded according to changes in the thermostat. OFS staff would adjust the thermostats to call for heating or cooling, Talli from Siemens would verify that the the BAS indicated that the system would react accordingly (picture above on the right), and OFS staff would watch the control valves turn and verify the temperature of the coils with a temperature gun (picture below on the right). While the systems reacting appropriately was generally the case, we did find one control valve for the baseboard heating that was unable to open or close because the metal baseboard cover prevented it from turning. This resulted in the perimeter heating being always on regardless of what the thermostat called for or what the FCU was doing. A simple change in control valve location will fix this.

Another potential issue was a discrepancy between the mechanical drawings and the actual HVAC system in one small room. The drawings called for a transfer grille between the small room with an unducted biosafety cabinet and a larger adjacent lab. Since there were insufficient existing wall penetrations, the contractor had used the location of the transfer grille to run the supply air duct. As a result, the room was very positively pressurized with the only path for air to leave being under the door into the hallway. You can see Kevin and Jay from OFS looking over the drawings with Talli from Siemens in the picture below.

We also looked at whether or not the fan coil units reacted to the manual fan speed switches (picture below on the right). Most did, though one seemed to only have an on / off reaction instead of the off / hi / med / low that was called for. We'll come back with a balometer or the testing adjusting balancing (TAB) contractor to confirm. The TAB contractor was supposed to be there on Friday (the reason we selected that date) but he didn't show up, so we'll have to come back to witness test some of the balancing, especially when it is done for the fume hoods. We also confirmed the occupancy sensors (Kevin is covering the sensor with masking tape in the picture below in the center) that control the lighting and the lighting levels at the bench level (Andrea is confirming the light levels in the picture below on the left). This space is not equipped with photo-sensors or dimming ballasts, so we weren't adjusting the light settings, just comparing the actual light levels to the Owner's Project Requirements and Basis of Design.

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