By Henry Townsend, senior mechanical engineer, WSP Group Africa 
All images by © RACA Journal | Benjamin Brits

This luxury residential development known as the ‘Jewel of Hyde Park’, comprises 1, 2 and 3 bedroom apartments, sophisticated security, and a lifestyle centre that offers residents the perfect synergy between work and recreation.

This project – by award-winning Legaro Property Development – is said to be the definition of exclusive urban designer living and is located in the sought-after, beautiful and tranquil Hyde Park suburb of Johannesburg. Its positioning enables quick commute to Rosebank, Sandton and surrounds, and is in walking distance from Hyde Park Corner – that itself offers a combination of high-end shopping, dining and entertainment options.

The Emerald further offers residents exclusive and convenient use of services such as a concierge, fibre and DStv ready connections, and the generously spaced Lifstyle Centre is home to many on site facilities too.

The construction of the Lifestyle Centre and HVAC installation took place between February 2020 and mid 2021, although the complete site development was ongoing at the time of publishing – with phase 3 in the process of selling and further phases under construction or being completed in the greater development.

For this project, the focus for WSP was to meet the HVAC requirements for the Lifestyle Centre, basement parking, laundromat and future provision for a dedicated IT room (also located in the basement).

The Lifestyle Centre, that takes up a significant portion of the site footprint, comprises the following elements to which considerations around the appropriate HVAC solutions were an influence:

  • Café
  • Lounges
  • Meeting rooms
  • 25 metre indoor heated pool
  • State-of-the-art technogym
  • Steam room
  • Hot yoga studio
  • Ice recovery bath
  • Administration area
  • Office
  • Toilet/changerooms/showers
  • Kitchen

The Lifestyle Centre also includes an outdoor heated pool and relaxation area on the first floor deck.

Client brief and considerations

For this project, WSP received the architectural plans from the client and the expectation was that we would come up with the best design and system components as experts in this discipline. The design methodology had to take into account a number of factors that would suitably service the needs of the occupants in each space – given the particular function.

Consideration of the aesthetics was also a very important part of the client brief and therefore it was vital to not only put an apprpropriate design on the table, but co-ordinate extensively with the client, architectural team and interior designers to make sure to achieve a win-win solution in terms of necessary climate control and having a pleasing visual outcome.

The design brief naturally then included compliance to building standards in terms of ventilation rates, and so on, and would further still maintain all best engineering practices. The systems that were therefore proposed for this project included a dedicated air handling unit (AHU) solution for the pool area and then a variable refrigerant flow (VRF) and direct expansion (DX) solution for the other spaces in the centre.

“Design methodology had to take into account a number of factors that would suitably service the needs of the occupants in each space.”

The VRF system consists of two separate heat recovery type systems serving the ground floor and first floor level units respectively, with a total installed cooling capacity of 91kW. The majority of the indoor units being hide-away type units concealed in the ceiling voids.

The dedicated AHU unit serving the indoor pool area consists of a DX cooling coil connected to three condensors, each with variable-speed driven compressors. The AHU, with a total cooling capacity of 145kW, contains a 1.7 metre diameter rotor type heat recovery wheel, and EC plug fans for controlling and maintaining the supply air and return air flows from the unit. The unit furthermore provides for an internal humidifier with humidity sensor, all communicating to the unit’s controller to assist with relative humidity (RH) control for the space. The AHU unit supplies full fresh air to the pool space at 3.2 m³/s, while also extracting the air from the space and exhausting directly to atmosphere.

HVAC system and selections

For this project it just made sense to select a VRF system because of the location of the rooms and the limitations that would exist in terms of condenser placements – being a high-end center with neat finishings. Daikin was the system of choice for WSP as they successfully won the appointment of the equipment tendering due to cost, specification compliance and quality.

When it came to the selections around the pool area, it is considered good practice to have a dedicated stand-alone system serving such an area. Since the rest of the system would comprise a refrigerant driven system, it was logical to also then include a refrigerant driven type unit providing the cooling to the pool AHU. This was achieved by a unit set supplied by Ecoaire through the same fair tendering process.