Project
platform . Offices are provided with individual ceiling mounted hydronic cassette units or ducted hide away units as preferred
by the client . All individual cassette units in individual offices are wired through motion sensors that offer additional energy saving when occupants are not stationed in their offices . A dedicated building management system ( BMS ) is used to control all aspects of the HVAC and plumbing systems , with a separate system by Danfoss to control the refrigeration aspects .
A view of the HVAC / refrigeration heat exchangers and pipe route to the plant room .
Refrigeration system and installation The refrigeration system consists of the combined chillers / packs and hybrid gas coolers , various blower coils in the main freezer and cold rooms , walk around freezers and fridges , etc . All Insulated panels for the cold rooms were built on-site , and some island type freezers were provided for the butchery section .
Stainless steel piping is predominantly used for all refrigerant circulation from the plant room all the way into the store at high level which then drops down to all blower coils which are scattered around the building in various freezers , cold rooms and fridges .
Danfoss expansion valves are used as required by each blower coil arrangement with appropriate oil traps in strategic locations .
A refrigeration main distribution board ( DB ) is located inside the refrigeration plant room which supplies power to all the refrigeration packs and all other remote DBs that include power for blower coils , power for electronic controllers for the expansion valves , power to all glass doors on fridges and cold rooms which incorporate heating strips built into the glass , and humidistats for anti-condensation purposes should this be required .
A Danfoss central controller installed on the main DB indicates all important features of the refrigeration systems and is connected to a remote touch screen monitoring system located in the maintenance managers office .
DIFFICULTY IN MEETING DESIGN SPECIFICATIONS One point of note for meeting the requirements of this project is that there was not a single solution in the form of a chiller that is available as yet for CO 2 systems and so a custom designed and built system was required to meet the client ’ s specification .
PROJECT EFFICIENCY AND SUSTAINABLE This project encompasses several aspects of efficiency and sustainability form the choice of CO 2 as the refrigerant of choice to the use of off-peak energy tariffs , as well as the use of free heat for domestic-use water heating .
Also , the application of a single system to achieve the entire facility ’ s needs is in itself very efficient and shows the clients strong support of sustainability .
ACS Consulting Engineers would like to thank all role players including the clients , Massmart , ITD Group and CRS / Matador for their contributions , commitment , and excellent performance for a satisfactory completion of this project - on time and on budget . RACA
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The hot water pumps and chilled water pumps in background .
RACA Journal I January 2023
" A dedicated building management system ( BMS ) is used to control all aspects of the HVAC and plumbing systems ."
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