Leading manufacturer of air conditioning solutions, Weatherite Air Conditioning Ltd, has designed, manufactured and installed two new Chillers at a Marks & Spencer store in Kensington, London.
The contract included the replacement of two 15 year-old York Chillers, which had reached the end of their useful life. The two new Weatherite Chillers were designed and pre-assembled at Weatherite’s manufacturing facility, dismantled and then re- built in situ onsite in a small internal plantroom at the busy London Kensington store.
Synergy Building Services Consultancy was employed by M&S to design the system and to calculate the installed cooling requirement at the store. Synergy then produced a scope of works to tender the replacement of the Chillers.
Synergy’s project consultant, Peter Simms, said: “We faced a number of hurdles with this job and Weatherite was the only company that developed a technical design solution that met those challenges.
“The old Chillers were externally mounted and needed a very high degree of attenuated barriers around the sides and over the top of the plant area which further added to airflow and fan power consumption.
“Synergy calculated the new store cooling load to be 1000 kW. In fact, the store needed an extra 300kw cooling over and above what the old Chillers were providing. As a result, Weatherite designed two new Chillers at 500kW capacity each to meet the new design duty.”
The existing two multi-cylinder, semi hermetic compressor chillers had to be dismantled in situ and taken through the building, piece by piece. Once the existing chillers had been dismantled, the existing framework was refurbished and modified to house the new air-cooled condenser coils and high efficiency EC Fans. Due to the very stringent noise constraints on-site, the condenser EC fans were fitted with AxiTops Diffusors for improved airflow and reduced noise levels. This all contributed to the new Chillers having a much lower noise levels than the existing Chillers without the need for attenuation to be refitted around the new Chiller plant.
The new Chillers were also supplied with new control panels and a Siemens control system integrated onto the existing BMS system.
The design and installation has been praised by Marks & Spencer’s programme manager, Paul Jenkins who said: “The design and engineering of the kit is absolutely superb and we were really pleased with the implementation of the project”.
When Marks & Spencer started the process of replacing the old water chillers, the team faced many challenges, particularly planning permission constraints and the length of time the project was going to take.
“So we worked with Weatherite to come up with a plan. Instead of building on the roof externally we would transport all the cooling kit internally into a plantroom within the store, the main advantage of this was that the process didn’t disrupt customers”, said Paul.
Building chillers on site in a small area took a huge amount of planning. The cooling equipment had to be transferred in pieces via a goods lift and every component had to be measured at Weatherite before bringing onto site- to ensure it could be transported through the store.
Weatherite Air Conditioning’s key account executive, Paul Ludlow, said: “The sequence of dismantling the old chillers and building the new plant, both within the internal plantroom and externally, had to be synchronised to avoid affecting store operation. We had to keep the existing Chiller No 1 running until we were able to decommission and replace that too.”
Weatherite also replaced the existing circulation pump with a twin head circulation pump to ensure resilience with the new installation allowing for some standby capability
Marks & Spencer’s Paul Jenkins continued: “The old system incorporated a four-compressor system that basically ran the cooling of the store. This was risky because if we lost one compressor we lost a quarter of the store’s cooling capacity.
“We’ve now put in place 16 screw compressors, so if we lose one, we only lose a 16th of the overall capacity. Meaning we’ve now got a lot more resilience.”
As well as designing, manufacturing and installing the chillers, Weatherite Service & Maintenance (Weatherite Air Conditioning’s sister company) is responsible for its upkeep of the equipment, which legally has to be maintained every six months.