The flagship Watermark building at Alba Campus Livingston was constructed in 1999 and provides 100,000 sq.ft of Grade A office space to three prestigious tenants.
The building uses low temperature chilled water for down flow units serving MER and SER’s, along with AHU coils and FCU. Low grade chilled water is also produced for passive chilled beams.
A total of 4No. packaged chillers are utilised to serve the building, these were installed with R22 refrigerant. The chiller plant at c.12 years old at the time of survey was in a serviceable condition and a study was conducted as to how best to proceed with R22 replacement. Plant replacement costs were in the region of £400k, and as noted the equipment was well maintained throughout its life to manufacturer’s requirements and SFG 20, thus it was decided to proceed with a drop in gas replacement.
c.450kg of R22 was removed and disposed off from the site. The chiller compressors were given oil changes along with replacement gaskets to the equipment oil side and replacement seals to solenoids and dryers refrigerant side. The units were then charged with R438a, this gas operates at a similar pressure to R22, and in this case has operated now for over 2 years with no reported loss in performance.