Technical
DESIGN CHANGES THAT REDUCE REFRIGERANT CHARGE
By Roy Naidoo , sales director at Danfoss Climate Solutions ( South Africa )
Soaring refrigerant prices and uncertainties around future supply have made reducing refrigerant charge an increasing priority for air conditioning manufacturers and cold room installers alike .
There are several ways it is possible to reduce charge without compromising performance . The optimisation of refrigerant charge has always been a key part of designing cooling systems and balancing their efficiency , reliability , performance and cost , and refrigeration engineers are once again looking at refrigerant as a key piece of the puzzle .
The two main reasons for this are , firstly , the fact that refrigerant prices are rapidly increasing in parts of the world . This is largely driven by dwindling supplies as traditional options are being phased down under European F-Gas regulations , with the aim of reducing emissions from industry to 70 % below 1990 levels by 2030 and decrease the EU ' s emissions of fluorinated greenhouse gases ( F-gases ) by 70 million tonnes ( mt ) of CO 2 equivalent , to 35 mt of CO 2 equivalent by 2030 .
In addition , other measures to limit the production of greenhouse gases under the Kyoto , Montreal and Kigali protocols have also had an effect . As a result , some refrigerants saw huge price increases , which can be attributed to stockpiling during the ongoing EU-wide phase-down of hydrofluorocarbons ( HFCs ) and the global HFC phase-down , which began in 2019 .
Secondly , the move to reduce Global Warming Potential ( GWP ) has resulted in growing use of flammable alternatives . In such cases , having less refrigerant charge materially increases the number of applications where a system can legally and safely be used .
So , in the current climate , reducing refrigerant charge is a key part of gaining a competitive advantage for both manufacturers and installers , while also satisfying end users , and maintaining profitability .
THE ADVANTAGES OF REDUCING REFRIGERANT Supplies of traditional refrigerants are being reduced and replaced with new alternatives , but the costs of certain refrigerants are unlikely to drop in the short term . These
Danfoss
A high proportion of charge can be found in the heat exchangers , so their design has a significant impact on a system .
fluctuating costs and supplies mean that designing for lower refrigerant charge also reduces a manufacturer ’ s exposure to risk should there be changes at short notice .
Reducing charge can also significantly improve installation flexibility . A reduced charge means A2L , A2 and A3 refrigerants can be used in a greater range of settings too , as it becomes easier to satisfy certain standards .
In addition , easier installation implies easier servicing . By making units simpler and lower in charge , servicing and maintenance can be carried out faster and more safely , further reducing total cost of ownership and offering a competitive advantage .
WAYS TO REDUCE REFRIGERANT CHARGE Reducing refrigerant charge can potentially make systems safer , more flexible , and more competitive . This can be achieved in several different ways , while at the same time possibly bringing additional benefits to the system ’ s full and part-load efficiency , or overall size .
www . hvacronline . co . za RACA Journal I June 2022 63