Alternatives to HCFCs in the Refrigeration and Air Conditioning Sector 54 S ection 02 Th ese five hydrocarbon-based chillers with a total capacity of 1175 kW are used in a fruit storage and handling facility with a capacity of 260 000 tonnes of apples per year. The hydrocarbon used is propylene (R-1270). The chiller cools a potassium formate brine solution. Presented with the opportunity of specifying the refrigeration for its new factory and being conscious of the failings of the DX (Direct Expansion) refrigeration systems, the customer was determined to ensure that any future system should provide the best in energy efficiency, flexibility, reliability and minimise the long-term environmental impact of HFC refrigerant gases with high-GWPs. The company - a food production factory – was subject to the CCL (Climate Change Levy) taxes imposed in the UK which heavily affected its production costs and had to be minimized. Furthermore, the company was within a very competitive marketplace and therefore the allowable capital cost envelope for the whole installation was tightly controlled and presented a challenge to meet the given criteria. With a storage capacity of 20 000 mt, the new building comprised refrigerated food preparation areas and various chill cold rooms operations, which narrowed down the options for systems that fully met the client’s required specification. The options considered included the traditional refrigeration systems designed on DX which use the HFC refrigerant R-404A or the natural refrigerant ammonia (NH3). However, the alternative that was finally selected was an indirect refrigeration system with propylene as the refrigerant in the chiller. Because HFC refrigerants are now subject to the new European Union F-Gas Regulation, some industries are now becoming reluctant to use these synthetic gases due to pressure to ensure their environmental credentials. Furthermore, the prospect of future EU Directives imposing increased restrictions on the use of such synthetic refrigerants encourages the industry to further consider the use of secondary refrigerant system engineering. Ammonia (NH3) is considered to be one of the most effective natural refrigerants available, but does present some challenges. It is toxic, caustic and hazardous, and therefore sometimes not considered as user friendly as the CFCs/HCFCs/HFCs. Ammonia systems also have additional requirements (which vary from country to country) to address the refrigerant’s flammability. After careful consideration of all pros and cons, the selection of an indirect system gave the food plant owner (F.W. Mansfield and Son) the opportunity to comply with criteria they considered important, such as: The potential for reducing energy consumption by ■■selecting state-of-the-art chillers - in this case, standard hydrocarbon chillers with a COP of 3.5 at 7°C exiting water and 30°C ambient temperature were used, manufactured by Frigadon, Sweden. Lower service and maintenance costs compared to DX ■■systems. Operation with an environmentally friendly refrigeration ■■system. Opportunity of using natural refrigerants such as ■■hydrocarbon R-1270. Using five standard hydrocarbon chillers allowing for a ■■low charge per circuit, close control of temperature, and redundancy in case one system stops. Opportunity of using biodegradable, non-toxic heat ■■transfer fluids - in this case, food safe Hycool® fluid was used. Minimisation of the carbon footprint.■■ Opportunity to demonstrate the system’s environmental ■■responsibility to its clients. The indirect system technology using hydrocarbons proposed by SRS Refrigeration Engineering was believed to provide the most cost-effective approach for reducing the overall climate impact. The benefits gained from choosing this refrigeration engineering technique resulted from the way in which all equipment was brought together in one compatible design. The introduction of the hydrocarbon chillers was facilitated by the fact that the installer offered a complete design service taking into account all necessary requirements to use the system in a safe and energy efficient way. Each of the five hydrocarbon chillers has four refrigerant circuits with 5.5 kg of R-1270 each. Each such unit has a cooling capacity of 235 kW at temperatures 32°C (ambient) and 0 to -4°C (in brine). Fig. 2.10 State-of-the-art cold store design to minimize the carbon footprint by using energy efficient hydrocarbon chillers. Fig. 2.11 Five air cooled chillers with potassium acetate as brine and hydrocarbon R-1270 as. refrigerant.