Written by John Ackermann
The mammoth task of providing the 1 000 Groote Schuur Hospital patients with three nutritional meals a day, 365 days a year, has since late 2022 become more efficient and done in a staff-friendly environment thanks to this successful project.
The low temperature cold rooms, blast chillers, medium temperature cold rooms, racking, trolleys and refrigeration systems were replaced at Cape Town’s Groote Schuur Hospital. The government funded hospital in Observatory gained international fame in 1967 when Dr Chris Barnard performed the world’s first heart transplant. The building still stands and houses a museum of that historical event, as well as other chemical departments. In 1984, two new wings were added to Groote Schuur to provide medical care for 1000 patients.
After 38 years of service, the catering department that provides all meals on site, needed to be replaced and brought up to international standards. Some of the original refrigeration plant, with open drive Dorin compressors, had been replaced with Bitzer semi-hermetic compressors. When calling for tenders to revamp the catering department and replace all the refrigeration plant, Bitzer, Dorin and Bock were specified as accepted brands of compressors.
PREFERRED SEMI-HERMETIC COMPRESSORS
After a transparent tendering process James Refrigeration cc – which has for many years done work for the Cape Administration – was successful in being awarded the contract and commenced work on the site early in 2022. The water-cooled condensers and the cold rooms with poor thermal performance, had to be stripped out completely and replaced, with minimal disruption to the daily catering services. James Refrigeration enlisted the design input of Gavin Wiffen of Eurocool, suppliers of Bitzer compressors and Jason Meredith, sales manager at SCM Ref Africa, to design special condensing units to fit in the limited available space. The parameters that the pipe runs be as short as possible and secured against vandalism, as set by the hospital engineer, Denton Smith, were some of the considerations that had to be taken into account by the design team.
DESIGNATED COLD ROOMS FOR DIFFERENT PRODUCTS
The catering services and cold rooms are located on the ground floor of the eastern wing of the hospital. 12 new cold rooms, each with its own air-cooled condensing unit, were installed. The rooms varied in size from 3.1 x 2.5m (blast chillers) to the bulk vegetable room, 3.5 x 8m and each allocated to a particular product, for instance vegetables in Room 6; dairy products in Room 7; meat in Room 8 and poultry in Room 9, to avoid any cross contamination of product and to maintain the optimum storage temperature for each product type.
For the specified cooling capacities, the following Bitzer semi-hermetics were selected:
- 11 x 2CES-4Y – 10Kw @ -5/45 – medium temperature rooms
- 4 x 2CES-4Y – 4Kw @ -25/45 – low temperature rooms
- 4 x 4HE-25Y – 19Kw @ -25/45 – blast chillers
- 1 x 4EES-6Y – 14kw @ -5/45 – medium temperature room
The structure of the blast chillers is in tandem with cold rooms, adjacent to the cooking area. From the cookers, the product is transferred onto trays, which are placed on trolleys, then wheeled into the blast chillers. After being chilled, the trolleys are wheeled directly into the adjacent cold rooms.
SECURITY OF EQUIPMENT AGAINST VANDALISM
To minimise pipe runs, the condensing units of the blast chillers, freezers and cold rooms, were placed in a space on the floor above. Chilled water piping from the large water chillers elsewhere and piping for floor vacuuming, is in the same space and limited the free space available for the condensing units for the new refrigeration systems. Having the condensing units in the upper floor space reduced the risk of vandalism, which could occur if the condensing units were at accessible levels in the wide driveway between the two wings of the building.
Simon James and his team from James Refrigeration were on site full time for nine months, while the old plant and rooms were replaced. “Keeping the catering services operational was a challenge. It went relatively smoothly by the close co-operation of our sub-contractors, Tectron Electrical, Insulated Panel Construction and the staff of the catering services department,” was said by Douglas James of James Refrigeration. “The new cold rooms, blast chillers, the layout of the rooms and the new trolleys, have vastly improved the production efficiency of daily meal quotas. The head of our department, Armanda van Schalkwyk, is thrilled with the new facility and its impact on staff morale,” was told by supervisor Tarryn Schilder.
Monitoring of the plant operating conditions is linked to the central plant management system and the catering staff are also required to manually check room temperatures twice per 24 hours and record the readings on log sheets.
LIFE CYCLE COSTS REDUCED
Although refrigeration is only one of the technical services under the direction of the engineer, Denton Smith, he used his past experiences to incorporate design features aimed at minimal long-term maintenance.
“Instead of floor level bumper rails on the outside of the insulated panelling, an outwards channel has been pressed in the aluminium checker plate and the space behind filled with wood. All handles on the insulated doors are of the vertical type with heavy duty sliding door hangers. These are all high maintenance items if not of robust design and properly installed. My involvement with the project was without serious headaches because of a co- operative project team. The old plant lasted over 30 years and we are confident with the new plant and improvements made, the hospital can expect a longer plant life and lower life cycle cost,” concluded Denton Smith, during a visit to Groote Schuur Hospital.
