ACR Journal

June | July 2020 AIR CONDITIONING 24 Volume 6 No.4 LG has been involved in one of its largest and quickest turnaround projects in the UK, utilising the flexibility and ease of installation of its new Multi V VRF system, working alongside WeWork and its contractors and installers to deliver 350 fan coil units and 28 condensers at Aviation House in central London. The project had a timeframe window of just 16 weeks, and the design and build project involved the refurbishment of 14,394m² of oce space over eight floors with a full CAT A fit-out. Vish Sodhi, National Specification Senior Sales Manager, LG UK Business Solutions, said: “The LG Multi V 5 VRF system was customised to match WeWork specifications. The timeframe was tighter than any previous project undertaken by LG in the UK and saw close liaison between LG and main contractors, KENTEX Services, to get the job completed on time. “The latest LATS software helped contractors and installers determine everything from changing evaporation temperatures, setting noise values and configuring the capacity for variable fan speeds to electrical inputs as per actual design and equipment selection. Overall, the project was a fruitful experience for everyone and we can proudly say this project has proved that LG is not only an HVAC solutions provider but also a true business partner.” KENTEX’s senior mechanical design engineer, Yousef Juji, said: “The LG Multi LG mounts rapid response 350 FCUs and 28 condensers installed in central London. V VRF solution was selected because it could be customised to match WeWork’s specifications and for the reliability of the system.” Aviation House sits between commercial and residential spaces and has a limited rooftop space for the external units, with some needing to be located at ground level. These required soundproof walls to ensure the noise requirements laid out in the UK’s national planning policy were met. The soundproof walls inevitably caused air suction capacity loss. Devising the most viable design of acoustic chamber through accurate analytical skills was the first hurdle to overcome. LG attempted to design several types of chamber but, according to CFD analysis, they were unlikely to achieve the targeted capacity without causing short cycling. At the third attempt, however, the design and analysis devised by LG achieved a successful CFD result that confirmed that it could reach the targeted capacity through smooth air suction. The next challenge was resolving the high evaporating temperatures due to the exposed ceilings in the fit-out design. To prevent condensation forming on the surface of the connected duct, all indoor units were designed to operate at a higher evaporating temperature than normal, targeting a discharge temperature of 12°C or above. However, factory produced indoor units are designed to operate at 6°C evaporating temperature which results in a discharge air temperature of around 10°C or 11°C. In order to achieve a higher discharging air temperature, fan coil performance data was developed for an evaporating temperature of 9°C for a supply air temperature of 12°C-14°C. The final hurdle was control - utilising a system that was compatible with the building’s Building Management System. This was less of a challenge in that LG had a sophisticated response ready and waiting. It had to develop an optimal interface with the on-site BMS to enable reliable, comprehensive control. For this LG installed its AC Smart 5 without the need for any additional devices. AC Smart 5 can link LG units to other existing BMS via BACnet. For this project, tests were carried out to ensure the controller was compatible with the Trend system of the building’s BMS and its controllers. John Skudder, Managing Director of project installers Skuddair, said: “The majority of WeWork projects are short term, quick turnaround programmes. Working with LG was impressive as the kit was delivered on time and support was always available.” LGMulti V VRF units on the rooftop at WeWork in Kingsway, London This project has proved that LG is not only an HVAC solutions provider but also a true business partner