Case Study: Chiller Retrofit
Client: Hapag Lloyd (UK) Ltd
Location: Barking, Essex
Solitair Services Ltd has been providing planned preventative maintenance to the HVAC plant at these premises since 2008. In preparation for the phase out of R22 refrigerant, we proactively discussed with our client various options with regard to their roof top chiller. The chiller is situated within a purpose built compound on the roof, with very little room to manoeuvre. Directly above the chiller is part of the roofs structural steel work and aesthetic metal louvres. This posed several logistical and costly implications should the chiller have to be replaced.
A further necessary consideration was that the previous HVAC contractor had already replaced the condenser coils and carried out a refrigerant retrofit. This had been done by changing the chiller from R22 refrigerant to R438A. However, the refrigerant retrofit led the chiller operation to become unreliable and prone to leaks so as a result, the chiller was reverted back to operating on R22.
As Solitair Services had already carried out several highly successful chiller retrofits, the client decided to opt for a full retrofit project to their existing plant. This involved:
- Decommissioning and removal of the existing Kobe screw compressor and replacing with a Hanbell screw compressor.
- Removal of the existing controls and control panels.
- Alterations and modifications to the compressor discharge, liquid and suction pipework.
- Machine shop fabrication of a new evaporator companion flange.
- Replacing the electronic expansion valve assembly.
- Manufacturing and installation of a bespoke control panel and associated controls, including variable frequency drive unit to allow infinite control of the condenser fans.
- The chiller also benefited from cosmetic repairs and a re-paint.
- Chiller fully commissioned to operate on R438A refrigerant.
- As the condenser coils had been recently replaced, these were re-utilised, along with the existing evaporator shell and condenser fans, into the retrofit project.
On completion of the project, the chiller was left fully operational and closely monitored over the coming months. Hapag Lloyd were delighted with the project having been completed with minimal disruption, efficiently and within budget. It has successfully proved to be a cost effective exercise that will inevitably give Hapag Lloyd many more years of reliable service from their chiller plant.
