Project
The building today looks extremely m0dern , with customers on its Facebook page commenting positively on its appearance and describing it as customer-friendly . The retail personnel also add that the air-conditioning is extremely comfortable .
THE HVAC SYSTEM AND INSTALLATION Stefanov describes the HVAC system as consisting of four independent installations :
• Two air-cooled Carrier chillers and four air handling units , together with spiral ducting and constant volume swirl diffusers , serve ground floor retail area
• Samsung DX inverter units were installed for mezzanine level offices and restaurant area
• Rooftop ducted unit was installed in the newly built annex and serves two additional retail levels
• Toshiba VRF heat recovery system serves main offices , situated at the top of annex building
“ Fire detection and sprinklers have been installed throughout the building . The VRF heat recovery system was implemented in the new offices and a heat pump rooftop unit was selected for the new retail levels as an energy efficient solution ,” he adds .
There were several design challenges in meeting the specifications and installation , says Stefanov : “ Firstly , performing heat load calculations was a mammoth task , as all the old and newly built areas are fully integrated – but have completely different purposes .
“ Secondly , the fresh air and extract air volumes had to be calculated and commissioned precisely in order to avoid kitchen and restaurant scents spilling over into the retail area and offices .
“ Thirdly , a sprinkler design also proved to be challenging to a degree , due to the diversity of various areas ’ allocation and space limitations . In the end , because of space limitations the pump room for the sprinklers had to be erected outside the main
Smoke vents control panel .
Staircase pressurisation control panel . building , as well as the fire water storage tanks .” COOLING / HEATING CAPACITY
Chillers :
2 x 406 kW Rooftop unit : 96 kW VRF system :
17 kW DX inverter units : 190 kW combined capacity
The builders work was performed by a building company NJ Construction . The design and selection of equipment also required working around the fact that there was pre-existing equipment . For instance , three of the AHUs were refurbished with a fourth purchased new . Choice of other equipment was dependent on a number of factors , explains Stefanov : space constraints inside the building ; ability to do the required function ; and finally the price .
“ Each product went out to tender , and I would select and recommend them to the owners , who had the ultimate say .
What eased the project management process for ODA Design was its expertise in using Revit – a 3D coordination software for mechanical , electrical and plumbing ( MEP ) services . Stefanov says that company ’ s investment in an intensive upskilling on Revit , combined with an involvement in the local building industry spanning 25 years , has proven tremendously beneficial to customising building information modelling ( BIM ) to suit the local contracting environment .
Within the mechanical aspect of MEP , it covers the following building services : HVAC ; fire protection , sprinkler and FHR systems ; and compressed air .
www . refrigerationandaircon . co . za RACA Journal I March 2023 37