© RACA Journal www . refrigerationandaircon . co . za RACA Journal I May 2024 43
Technical
GAS ENGINE VRF SYSTEMS – DEAD IN THE WATER ?
By Patrick Burke , SAIRAC Fellow
The following article is a follow-up to the technical article ‘ A case for gas engine VRF systems ’ written by Patrick Burke in the RACA Journal April issue .
Following the numerous warnings concerning the future longterm supply of Liquid Natural Gas ( LNG ) in South Africa , the general interest in this type of potential energy source had grown considerably with articles now appearing regularly in several leading business news publications .
While it is difficult at this stage to decipher the ‘ wheat from the chaff ’, it would seem that the main factor governing the current negative sentiment is the recent decision by Sasol to retain its LNG production for its own consumption , thus preventing local users and suppliers from procuring previously freely available stocks .
Given the legitimate concerns for future local LNG supplies , one can fully understand their decision to conserve production for their own use due to their plans to displace coal to support its decarbonisation .
However , to rely on imported stock will no doubt result in higher costs and as such , could well prove uneconomical for current local suppliers and users of LNG to operate going forward . It would seem that the local liquid natural gas supply industry is indeed under severe threat , with the Industrial Gas Users Association of South Africa warning of a gas supply ‘ day zero ’.
In the longer term , however , the future of LNG appears a little more encouraging . The exploration of future gas and oil fields in our southern Africa region continues unabated , with the general consensus that new untapped fields exist off both the East and West
Coasts . The big question is : how economical will it prove to produce ? Only time will tell , I suppose .
At the HVAC & R Japan exhibition in 2016 , it is reported that one leading manufacturer unveiled a so-called ‘ hybrid ’ VRF system , that connected a gas-engine VRF system and an electric VRF system to the same refrigerant circuit , thus allowing one
Patrick Burke , RPM Consulting Engineers and SAIRAC Fellow .
product to operate on two energy sources . The hybrid can switch its energy source to take advantage of the available unit costs of both electricity and natural gas , as applicable .
In my opinion , this could well be a possible answer to South Africa ’ s unique energy supply situation ( in the event of both potential energy solutions becoming more difficult to source ) thus , providing a semblance of choice for the end-user .
In any event , as previously stated , only time will prove this to be possible , as all indications are that new local gas fields will only be operational from 2030 . RACA
© RACA Journal www . refrigerationandaircon . co . za RACA Journal I May 2024 43