Impact of current refrigerant replacement used in Universiti Teknologi Malaysia

Abstract

Many institutions of higher education have begun to integrate sustainable development into their system. Universiti Teknologi Malaysia (UTM) was chosen as a case study to access the impact of replacing hydrochlorofluorocarbon (HCFC) with hydrofluorocarbon (HFC) in its air-conditioning systems. UTM has installed new air-conditioning units using R-410A (HFC) and replaced current systems that use R-22 (HCFC). UTM also have used a chiller unit using R-134A (HFC) replacing with old refrigerant which is R-123 (HCFC). Currently UTM, does not possess a proper guideline with sufficient inventory database to assist the management team in making any decision on replacing the current HCFC with HFC or any other refrigerant that is more environmentally friendly. The objective of this research is to (1) Estimate the Total Equivalent Warming Impact (TEWI) and leakage rate in air-conditioning unit that currently use R-22 (HCFC) and R-410A (HFC) as refrigerants; (2) Differentiate in terms of TEWI for R-32 (HFC), R-161 (HFC) and R-290 (HC) as alternative to substitute current refrigerant and (3) Determine potential reclamation of used refrigerant R-123 (HCFC) that can be recovered back to the system as it is possible to avoid direct release to the atmosphere. TEWI takes into account both direct and indirect emissions in four maintenance zoning areas. The leakage rate was determined by retrospective approach method. Currently, in all four maintenance zone there are 4,261 units which is 64.1% of split air-conditioning using HCFC. Highest TEWI value was detected in Zone 1 which is 130,057.14 t eq CO2/year while Zone 4 has the highest leakage rate among the four zones which is 473.79%. To support decision making, this study differentiate TEWI of HFC and HC as alternative substitute refrigerants. The result shows that carbon emission for R-32 (HFC) is 254,225.9 t eq CO2/year, R-161 (HFC) is 250,896.0 t eq CO2/year and R-290 (HC) is 250,884.9 t eq CO2/year. In order to manage the used refrigerant, this study also focused on refrigerants with recovery potential which is Chiller at Block C12 which is one of the targeted unit to dispose for replacement of HCFC. A sample of HCFC was recovered from the chiller unit to undergo the reclamation process. From the impurity test all samples passed the AHRI-700 standards. Hence, the results indicated that the sample can undergo reclaim process. A total of 79.21% of HCFC was recovered at the end of the recovery process and can be reused in the same system. From this study, it would help Universiti Teknologi Malaysia Office Asset and Development (UTM OAD) to develop a plan to decide use of environmentally friendly refrigerant with no Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP) in new and existing air-conditioning unit systems. In conclusion, the method of data collection can influence HCFC's phase-out as required by national regulation. This data would act as a guideline to ensure a successful phase-out is being carry out and assist in determine the best refrigerants to be replace in the future in the conditions of higher education institutions towards sustainability.