RACA Journal June 2019 | Page 48

Projects Two new Evapco induced draft condensers were installed with closed coupled mono-block type circulating pumps that circulate water over the galvanised coil. A closed loop cooling circuit for the compressor oil is also installed in each unit. Each condenser has a divider plate between the four fans to be able to switch off two fans when not needed so as to avoid short cycling the air. A condensate collection tank is used to collect all the water from the evaporators when defrosting, which is then pumped to one Evapco condenser. The water treatment of these condensers was specially adjusted to accommodate this condensate water. 1 Heat rejection rate: 1 111.4kW (each) Condensing temperature: 33°C Wet bulb temperature: 21°C A monitoring system from Carel Controls called the BOSS system was used. All the PLC equipment used to control the plantroom as well as all the valve stations for the cold rooms are wired via building management systems (BMS) cards. Additional PLC units have been installed to accommodate evenly spaced temperature probes installed in all three holding freezers as well as the chill store and the five blast freezers. The monitoring system is set up to send a report of all the various temperatures to the client every day. The BOSS system is also accessible remotely to check system operations off site. It has once again been proven that with efficient project management and the necessary communication, anything is possible. 2 3 EFFICIENT PROJECT MANAGEMENT It was immediately clear that the installation period of this project would be extremely tight, with the site handover expected to be on 1 March 2018 and the intended practical completion to be on 1 of August 2018, including all the building works and refrigeration. Stuart Walls and his team from Capex were appointed as the principal agent of this project. They compiled a detailed programme that was closely monitored every day to ensure all the contractors were up to date with their individual responsibilities and programmes. Design changes and customer preference delayed the delivery of the capital equipment of the refrigeration installation, but because of efficient project management from MRE’s team as well as effective communication and planning from Capex, they were able to meet the deadline set out. It was mentioned by all the contractors and bystanders that the deadline was impossible, but it has once again been proven that with efficient project management and the necessary communication, anything is possible. RACA 1. 2. 3. 46 RACA Journal I June 2019 Evapco condensers and liquid receiver. Distributing the cool air over the products. Products ready for dispatch. www.hvacronline.co.za