Laboratory building accommodating laboratory and write-up areas in East Kent.
The air change rate for laboratory supply and fume cupboard extract remained constant at 24 air changes per hour. Each of the supply and extract fans had been previously fitted with a Variable Speed Drives (VSDs) however, they were running at fixed speeds to provide a laboratory to corridor pressure differential of 15 Pascals.
A “sash-close” regime was instigated within the laboratories, allowing the air volume to be reduced for each of the air systems at night.Air volumes were measured by way of a Pitot traverse and a night-setback required volume was calculated taking account of the laboratory’s specification. The software was then modified to allow this enhanced functionality.Much of this work had to be undertaken “out of hours”; consequently, the return on investment was calculated at 9 months.
This calculation has been based on the reduction of fan power however; it does not include the additional energy savings associated with the conditioning of treated spaces.
Measurement of Savings Achieved
Annual Energy Reduction = 350,000kWh Annual CO2 Reduction = 192 tonnes Annual Cost saving = £28,000 Cost of implementation = £21,000
Return on Investment: Payback period = 9 months