www . refrigerationandaircon . co . za RACA Journal I June 2023 27
Feature been adapted to work effectively in smaller , multi-occupancy spaces , such as individual rooms , meeting rooms etc , where it allows individual occupants to adjust the temperature of their workspace to suit their own needs .”
The challenge in the hotel project was to install a VRF system that met all the necessary acoustic requirements and that would accommodate the various temperature preferences of the hotel ’ s guests , while meeting the necessary budgetary requirements . “ VRF systems are a good choice for such projects because they are efficient , modular , and offer individual temperature control for each room or space .”
The hotel project involved the installation of 34 individual VRF systems , with one centralised controller governing the building ’ s heating and cooling mode . The building manager determined when the changeover from summer to winter would occur for each system , based on the specific temperature zone needed for guest comfort . The system has proven to be successful , with high energy efficiency and individualised temperature control for each room .
However , Wallett points out that while VRF systems are an effective solution for retrofitting multi-use buildings they are not always the practical choice for every situation . “ For example , chilled water generators are still a popular choice for larger buildings that have a large cooling demand . VRF systems are often chosen for their cost-effectiveness , ease of installation , and energy efficiency . Moreover , the system ’ s modular design makes it easy to repurpose as necessary , depending on the building ’ s changing needs ,” says Wallett .
Aside from the hotel project , there are several other notable VRF heat pump retrofit projects around the world . Wallett describes one such example as being the Asia New Bull project in China , where an existing 36 -story building was converted into a hotel . The project was challenging due to the densely populated space and the need to accommodate individual temperature preferences for each guest . However , the VRF heat pump system was able to meet these requirements while maintaining high energy efficiency and cost-effectiveness .
He notes that VRF systems are also being used for retrofitting existing package plants , where traditional systems have lower efficiency ratings . “ By replacing the traditional condensers with VRF condensers , the package units can achieve efficiency ratings of up to 4 to 5 COP ( coefficient of performance ), compared to the traditional 2.5 to 3 COP . This energy efficiency comes at an up-front cost , of course , but the payback period is well within what financial experts consider to be suitable use of the system ,” he says .
The VRF system is also being used increasingly in other applications , such as hospitals and manufacturing processes . By replacing traditional condenser fans with variable-speed fans , VRF technology can significantly increase the efficiency of these
RPM Engeering Group AHI Carriers
VRF Packaged unit .
The outdoor units incorporate variable heat exchangers , such as a main HEX and sub HEX , which allows the outdoor unit to control the flow of refrigerant through the heat exchangers .
systems , resulting in energy savings and reduced running costs . This technology has been particularly effective in the packaging industry , where energy efficiency is a key concern .
Wallett adds that a reason for the popularity of VRF technology is its ability to be customised to suit specific building requirements . “ For example , in multi-tenant buildings , the VRF system can be used to accurately measure individual energy consumption , allowing for more accurate billing . Additionally , the system can be used in conjunction with other technologies , such as solar panels or geothermal systems , to further increase energy efficiency and reduce costs .
“ With continued development and innovation , it is likely that VRF technology will continue to play an increasingly important role in the design and construction of buildings in the future ,” says Wallett . RACA
“ VRF systems are an effective solution for retrofitting multi-use buildings .”
www . refrigerationandaircon . co . za RACA Journal I June 2023 27