www . refrigerationandaircon . co . za RACA Journal I February 2024 37
Contributor
THE CASE FOR GAS ENGINE VRF SYSTEMS
Contributed by Patrick Burke Fellow : SAIRAC
A Gas Heat Pump ( GHP ) Air Conditioning system , is a conventional VRF ( Variable Refrigerant Flow ) system , where the compressor is driven by a gas engine using natural gas . The capacity is controlled by the engine speed , thereby matching the varying load to suit the required conditions .
This gas-powered HVAC System is available in both Heat Pump and Heat recovery versions to suit a broad range of design applications . The benefits of GHP are inter alia , lower
CO 2 emission , reduced electrical power consumption and more effective Heating .
FINDINGS AND OBSERVATIONS In search of some general information on the internet recently , an Industry White Paper titled ‘ GAS HEAT PUMP TECHNOLOGY ’ caught my attention . Sponsored by some 14 local US and Canadian gas distribution companies , the paper identifies opportunities and strategies to accelerate the market acceptance of GHPs in North America .
In effect , the paper claims that GHPs have the potential to reduce energy use and greenhouse gas emissions across various climates for both the residential and commercial markets in North America . As such , these sponsor companies are eager to accelerate and advance the commercialisation of GHP technologies for Heating , Ventilation and Air Conditioning ( HVAC ).
Given our electrical power supply issues , could this type of technology be a solution ( or even a partial solution ) to our problems in this regard , at the same time addressing the issues surrounding climate change ?
As we know , the technology itself ( VRF ) is well understood in South Africa since first introduced way back in the 1980s . With many role players and suppliers of quality equipment serving our local market , VRF is probably the most dominant category of comfort cooling options currently on offer .
So why then the lack of market development for VRF gas heat pump technology in South Africa ? While there is probably a call locally ( albeit small ) for this type of VRF System , no one to my knowledge , is actively marketing their product - even though several Leading HVAC companies manufacture this type of product . One would think that this would receive serious consideration given our crippling electrical power situation . Not so ! Obtaining any information on the subject is tantamount to pulling teeth . From all accounts , even the local guys have no
marketing strategy from their principals in this regard .
• Could it be the availability of LNG / LPG gas ? Surely not ! This is currently produced in Mozambique , Mossel Bay and elsewhere , and piped and / or transported into our major cities and commercial centres , apparently without any major issues .
• Could it be a matter of running costs , LNG versus electrical power ? Maybe it ’ s simply not economically viable locally at today ’ s comparative rates . By the way , LNG is substantially cheaper than electrical power Pat Burke . in the US .
• Could it be the cost of setting up the required site infrastructure and safety requirements ? In this regard , many local commercial buildings and shopping malls are already piped for LNG to serve their restaurant kitchens , hot water boilers etc .
• Capital equipment costs : Gas engine VRF versus standard electric-powered VRF equipment . What is the difference in rands and cents ?
• Operational costs : With regard to maintenance and repairs , gas engine versus standard electric VRF equipment , suppliers of this equipment claim 10 000 hours of maintenance-free operation or as long as five years .
• In weighing up the pros and cons , my scrutiny has yielded the following prognosis , based on the information at my disposal .
• As already stated , LNG / LPG is available in bulk supply in all major centres .
• From all accounts , the cost of LNG / LPG compares favourably with electrical power ( kg versus kWh , based on available information ). In this regard , international sources indicate that natural gas VRF systems produce substantially lower overall costs .
• The cost of site establishment and safety requirements will
RACA Journal
www . refrigerationandaircon . co . za RACA Journal I February 2024 37