Fluorocarbon gas consumption can contribute in direct and indirect impact to the environment such as ozone depletion and global warming due to fluorocarbon gas leakage and increase in electricity consumption, respectively. This study is focused on early detection of fluorocarbon gas leakage on refrigeration unit to determine scenario of fluorocarbon gas leakage management and estimate reduction potential of greenhouse gas (GHG) emission and the co-benefits in energy saving. In this study, the Internet of Things (IoT) that utilized ultrasonic sensor detection system to detect early fluorocarbon gas leakage was installed at the chiller unit at two selected facilities, A and B. After installation, the data was monitored, and any gas leakage detected was countermeasure. Results from the data monitoring, reduction potential of GHG emission and energy saving co-benefits calculated by using formula adopted from the Japan Refrigeration and Air Conditioning Industry Association, (JRAIA). The monitoring results found that different response rate towards leakage detection between two facilities A and B (chiller 1 and chiller 2) contributes to 33.9%, 60.6% and 21.3% of fluorocarbon leakage. Installation of IoT based refrigerant leakage device proved that early detection and on time countermeasures successfully reduce 30 t-CO2e/yrs (facility A) and 460 t-CO2e/yrs (facility B). Thus, proper fluorocarbon gas management is important to reduce environmental impact of the fluorocarbon gases.
Research Article
Refrigerant Management by Using Iot Technology With the Co-benefit in Energy Saving at Malaysia Food and Cold Chain Sector
https://doi.org/10.21203/rs.3.rs-2220996/v1
This work is licensed under a CC BY 4.0 License
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fluorocarbon gas
refrigerant leakage
GHG emission
energy saving
refrigeration system
refrigerant management
Fluorocarbon gases is widely used around the world especially in refrigeration system as cooling agent to absorb heat during the Phase change from liquid to gas in the refrigeration system (Dincer, 2003). However, the utilization of fluorocarbon gases such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) becoming a big issues globally due to high ozone depletion potential and high global warming potential warming (Wang et al., 2014).
In Malaysia, the used of CFCs was completely banned. Currently, Malaysia is in processes to Phase-out the used of HCFCs and Phase-down the HFCs. In 2020, new regulation on refringent management namely Environmental Quality (Refrigerant Management) Regulation 2020 was gazetted in Malaysia. This regulation introduced new policy regarding the management of HCFCs refrigerant but there is no specific regulation or guide on proper handling of the refrigerant available in Malaysia. The control of refrigerant in Malaysia only focused on import/ export activities. Basically, the refrigerant management in Malaysia is not well establish and not fully enforced compare with others developed countries such as United States (US), South Korea, and Japan.
Fluorocarbon gas management in Malaysia mainly control from the import/export activity and production of the refrigeration and air-conditioning unit only. There is no regulation focusing on the technical control measure available in the country that aiming to prevent fluorocarbon from released to the environment. Without proper management and handling of the fluorocarbon refrigerant during operational of refrigeration system and maintenance activity, it will harm the environment as well as increased the operational cost of the system.
The optimum amount of fluorocarbon in the refrigeration system plays an important role in the operation efficiency of the system, reduce in electricity consumption and greenhouse gases (GHG) emission, where it can lowering the maintenance cost due to malfunctioning of the system (Koronaki et al., 2012). Results from laboratory test conducted by Japan Refrigeration and Air Conditioning Industry Association (JRAIA) and Japan Air Conditioning and Refrigeration Testing Laboratory (JATL), found that the shortage of fluorocarbon gas will decreasing the cooling capacity of the equipment, extended the operating time to meet the cooling load and increase in electricity consumption as shown in Fig. 1. In addition, as the refrigeration system meet the cooling capacity, the optimum operating condition of the system can be reached for instance by meeting with temperature setting, an optimum amount of fluorocarbon gas, well-functioning of the defrosting system and others. Hence, amount of fluorocarbon gas needs to be maintained to reduce the indirect GHG emission impact due to electricity consumption (Cascini et al., 2016).
In Malaysia, consumer site monitoring still very lack in term of control leakage of fluorocarbon gas and thus increased in electricity consumption and operational cost due to inefficient cooling unit. Moreover, effect on environment due to the direct released of fluorocarbon gas is not the priority the consumers in Malaysia. The current practice to detect refrigerant leakage in piping system of refrigeration unit is by utilizing devices such as fluorescent detector, electronic detector, and bubble detector, which is highly depends on the experience of the service technician.
Recently the application of information and communication technologies (ICT) in condition monitoring (CM) become more popular and have attracted academia and industry attention to optimize operational condition of mechanical and electrical system of the refrigeration unit. The sensor device as one of the main component together with the communication and network devices (Ejaz et al., 2017), have been existed since the 1990s even though the term of IoT has been introduced in 1999 (Perera et al., 2014). The IoT-devices is useful tool and widely used for energy management due to their ability to capture data from the inside of the system and transfer it to the server for real-time energy consumption monitoring (Tan et al., 2017). Yoo et al. (2017), the effective way to adapt with this small leakage by indirect detection which gathers the information from inside the system (Yoo et al., 2017) by using the Internet of Things (IoT) which involved sensor. operational of refrigeration system and maintenance activity released has been done, however and an increase in electricity consumption. Thus, early detection of fluorocarbon gas leakage by using direct and indirect method is important to avoid direct release to the atmosphere. However, there is limited study available focusing on fluorocarbon gas leakage monitoring using IoT-device.
Therefore, this study was carried out to utilize ultrasonic sensor detection system to early detection of fluorocarbon gas leakage. So, the aim of this study is to determine the scenario of refrigerant leakage management and the reduction potential of carbon and greenhouse gas (GHG) also co-benefits in energy saving, that will be contributing on saving the electricity consumption and operational cost of the of the equipment.
2.1 Installation of fluorocarbon gas leak detection device
This study is conducted at food manufacturing (Facility A) and commercial facility (Facility B) in Malaysia. This project is involved in the installation of early fluorocarbon gas leakage detection device on a chiller unit at Facility A and two chiller unit at Facility B as shown in Fig. 2.
The fluorocarbon gas leak detection device that used in this study is combined with the Internet of Things (IoT) that utilized ultrasonic sensor that are able to collect various data from the refrigeration equipment such as fluorocarbon gas temperature, electric current and ambient temperature by using the ultrasonic sensor.
The leak detection device was installed around a refrigerant pipe close to the sight glass in order to detect fluorocarbon gas leakage at refrigeration equipment. The temperature sensor is installed at four different points to detect different temperature, which is ambient temperature, refrigerant temperature, suction point temperature, and discharge point temperature. Except for the ambient temperature sensor, other sensors installed on the piping system of the refrigeration equipment. The current sensor was clamped at the R Phase to detect the electricity from the compressor. Data from each sensor was collected and stored at the control panel device for 300 seconds before send to the server in real time through a wi-fi router. This device provides centralized and remote monitoring of the refrigeration equipment where can be monitored through a computer or/and smartphone. Figure 3 shows the mechanism of the early fluorocarbon gas leak detection device which involved installation site, technology developer and academic researcher.
2.2 Monitoring of fluorocarbon gas leakage
Before installation, the preliminary data collection was collected to understand the history of refrigeration unit. After the installation of refrigerant leak detection device, the data was monitored. There are 3 Phases of monitoring activities (Table 1). The first Phase of data monitoring is to monitor the normal working operation condition of the chiller unit at each facility. This monitoring activity was carried out for one month to determine leakage problem. Then, after the leakage problem was solved, second Phase monitoring was carried out to monitor the changes of the fluorocarbon gas leakage, also known as flash gas incidence, and electricity consumption oscillation graph trend after countermeasure. Lastly, the third Phase or final monitoring of the chiller unit was carried out to observe the changes in the result of working operation before and after countermeasure. The response time to identify and repair fluorocarbon gas leakage by the service contractor or facility manager from each facility had been monitored during this study.
| Phases | Preliminary | 1 | 2 | 3 |
|---|---|---|---|---|
| Installation and history data collection | The actual scenario of refrigerant leakage | After countermeasure | Final monitoring | |
| Duration | 1 or 2 day | Week 1 – Week 4 | Week 6 – Week 11 | Week 12 – Week 17 |
2.3 Estimation of reduction potential
The history data collection of electricity price and maintenance report relating to the fluorocarbon gas was collected from each facility in order to calculate electricity consumption and potential reduction of direct and indirect emission. The reduction potential was estimated for 12 months (1 year). The saving potential was calculated by comparing the electricity consumption on business as usual (BAU) to electricity consumption after installation of fluorocarbon gas leakage detection device (where the refrigeration system is functioning in optimum condition). Eq. 1 (1) to Eq. (6) are the formulas that were used to calculate energy saving, electricity consumption, and total of direct and indirect GHG emission adopted from The Japan Refrigeration and Air Conditioning Industry Association (JRAIA).
i) Direct GHG emission calculation, Eq. (1),
$$Total direct = Mass of fluorocarbon gas added \left(kg\right)/1000\times GWP Eq. \left(1\right)$$
where GWP value for R-22 is 1810 while R-507 is 3985
ii) Indirect GHG emission calculation, Eq. (2),
$$Total indirect = \frac{Electricity consumption \left(kWh\right)}{1000 M}\times grid emission factor \left(\frac{tC{O}_{2}}{MkWh}\right) \text{E}\text{q}. \left(2\right)$$
where grid emission factor obtained from Tenaga Nasional is 0.694 tCO2 /MWhr.
iii) Energy saving, Esave, Eq. (3)
\({E}_{save} \left(kWh/yr\right)= \left[{Q}_{ave.\left(bed\right) }- {Q}_{ave.\left(aed\right) }\right]\times 365 days\) Eq. (3)
where Qave.(bed) (kWh) is average electricity consumption before early detection, which is daily electricity consumption estimated during Phase 1 monitoring. Qave.(aed) (kWh) average electricity consumption after early detection that was calculated during Phase 2 of monitoring (after countermeasure).
iv) Average amount of electricity saving, Qsave, Eq. (4)
\({Q}_{save}=\left[{Q}_{ave.\left(bed\right) }/Average operation \left(\%\right)\right]\times Ideal rate of operation \left(\%\right)\) Eq. (4)
v) Electricity consumption on normal condition, Qnor, Eq. (5)
\({Q}_{nor}=\left[{Q}_{ave.\left(bed\right) }\times {Q}_{save} \right]\times 365 day\) Eq. (5)
Where Qnor is electricity consumption under normal condition (kWh), Q(ave.(bed) average electricity consumption before early detection (kWh) which is average operation is operating rate during Phase 1, and Qsave is the average amount of electricity saving (kWh).
vi) Electricity cost reduction, Qcost(red), Eq. (6)
\({Q}_{cost\left(red\right)}= {Q}_{save}\times 30 days \times Electricity price (RM/kWh) (RM \times 12 month\) ) Eq. (6)
3.1 Facility A
Facility A is categorized as a food industry sector that involved a refrigeration unit. At this facility, the early fluorocarbon gas leakage detection device was installed on one refrigeration unit at the freezer room. This chiller system is utilized R-22 as a cooling agent. Table 3.1 shown the data monitoring for freezer room at Facility A.
3.1.1 The scenario of refrigerant leakage
During Phase 1, throughout 4 weeks duration of data monitoring, 33.9% of fluorocarbon gas leakage has been detected which indicates the refrigeration unit operating with shortage of fluorocarbon gas. This scenario occurs due to direct released of fluorocarbon gas to ambient by the service contractor due to frost issues. The contractor later recharged 7.3 kg of fluorocarbon gas to solve the frost issue near the compressor as shown in Fig. 4. However, insufficient of fluorocarbon gas in the refrigeration system cause defrost activity could not work effectively due to low fluorocarbon gas temperature. The low fluorocarbon gas temperature caused fluorocarbon gas evaporates more quickly and close the expansion valve. Whereas eventually cause evaporator condensation to form a heat insulation layer and transfer the expansion point to the compressor return air, causing the compressor return air to frost over (Van, 2019). Based on Table 2, temperature of fluorocarbon gas during the Phase 1 is lower (35.6 ˚C) compared to Phase 2 (37.5 ˚C) after frost issue has been fixed. The high fluorocarbon gas temperature will short the defrost periods (Kim et al., 2013; Van, 2019; Badri et al., 2021; Mahvi et al., 2021). Therefore, the defrost activity are not effectively occur due to low in fluorocarbon temperature.
| Phases | Phase 1 | Phase 2 | Phase 3 |
|---|---|---|---|
| Operating Rate (%) | 91.8 | 96.3 | 95.1 |
| Total Power Consumption (W) | 2, 359, 330 | 4,751,261 | 4,958,965 |
| Daily Electricity Consumption (kWh) | 112.3 | 137.7 | 137.7 |
| Fluorocarbon Gas Leakage (%) | 33.9 | 0.7 | 1.9 |
| Ambient Temperature (oC) | 31.3 | 32.0 | 32.6 |
| Liquid Refrigerant Temperature (oC) | 35.6 | 37.5 | 38.5 |
| Discharge Temperature (oC) | 89.0 | 61.5 | 51.6 |
| Suction Temperature (oC) | 7.7 | 2.33 | 0.7 |
In Phase 2, the frosting issues from Phase 1 has disappeared (Fig. 4) after16.3kg of fluorocarbon gas was recharged at week 6 and the leakage rate significantly reduced from 33.9–0.7%. Where, refrigeration system achieved optimum level of fluorocarbon gas. Figure 5 shown the condition of sight glass on the refrigeration unit before and after recharged of fluorocarbon gas. The sight glass at the evaporator outlet is used to observe the changes of the fluorocarbon gas level (Bai et al., 2018; Lei et al., 2022; Modi et al., 2022; Yoon et al., 2022) in the refrigeration system during the recharge activity. The present of bubbles on the sight glass before the recharged activity indicate undercharging condition of fluorocarbon gas (Saravanan et al., 2022; Sidney et al., 2022). When the fluorocarbon gas is charged, the clear view of sight glass is observed. This indicate that fluorocarbon gas has achieved minimum effective charged for this refrigeration system (Kocyigit et al., 2014; Saravanan et al., 2022).
However, the increase in electricity occurred after fluorocarbon recharged, from 112.3 kWh to 137.7 kWh. This is possibly because the operation of the compressor has been optimized. However, further inspection was conducted and found that the cold air escaped from the freezer room door, cause loss of cooling capacity during the opening and closing the freezer room door. Thus, more heat to be drawn in from the outside, necessitating more energy for cooling to compensate for the temperature drop (Gao, 2019; Pongsupat et al., 2022). Referring to this issue, a PVE door curtain has suggested to be install as a prevention measure to reduce the infiltration of warm air. When this facility installed the door curtain, it can lead to reduce up to a 48% reduction in energy use (Rai et al., 2019; Pongsupat et al., 2022).
Unfortunately, in Phase 3 the electricity consumption does not show the reduction (137.7kWh). This is because, prevention measure has not been encountered. Furthermore, there have been reoccurrences of fluorocarbon gas leakage, ranging from 0.7–1.9%. In order to avoid a large incidence of fluorocarbon gas leak, further inspection of the refrigeration system is required to discover, check, and repair the leaking point. According to the Yu Gao et al. (2022), fluorocarbon gas leaks are not visible at first, but they will persist for a long time and have a severe impact on the entire refrigeration system (Yu Gao et al., 2022).
Figure 6 shows the overall incidence trend of fluorocarbon gas leak and electricity consumption of this facility during these four months of monitoring. The green line of the graph indicates the incidence of fluorocarbon gas leak while the blue line indicates the electricity consumption. Based on this graph, leakage of fluorocarbon gas (week 1 until week 6), is higher (33.9%) due to the significant shortage of fluorocarbon gas (refer red box) as the service contractor released the fluorocarbon gas proposedly on the week 1. This situation shows that, hired service contractor at this facility lack knowledge on best practice of fluorocarbon gas management and refrigeration equipment handling.
In addition, the intermittent operation of the compressor is occurred during Phase 1, which is extreme shortage condition of fluorocarbon gas. Under low heating load levels, the compressor operates intermittently due to thermostatic control (Fan et al., 2018). Figure 7 shows the dissimilar trend of electricity consumption on week 1 (before recharge) and week 17 (after recharge). Based on the graph, it shows the intermittent operation occurred before the refrigerant recharged. Once the refrigeration system was at the optimum level of fluorocarbon gas, the compressor has operate in optimize condition. At the same time, the defrosting operation schedule also changes from every 6 hours in Phase 1 to every 4 hours in Phase 3. Which it takes 17 weeks to achieve a normal defrosting operation for freezer room and solving the problem regarding the ice frozen near the compressor.
3.1.2 Reduction Potential
The voltage usage of Facility A categorized under Tariff B that is for commercial facility with low voltage. In order to calculate the cost reduction potential, the Facility A unit price of 0.509 RM/kWh for Tariff B is used. Table 3 shows the result of the reduction value for the actual reduction during the monitoring and reduction potential of the Freezer Room.
Table 3: Reduction Simulation for Freezer Room
After four months of monitoring, the simulation of the actual reduction cannot be calculated due to an increase in electricity consumption after fluorocarbon gas recharge. So only the reduction potential of the Freezer Room during the normal operation can be calculated. The normal operation is indicating the Freezer Room operated with optimum amount of fluorocarbon gas and without malfunction of the chiller system. Thus, by early fluorocarbon gas leakage detection, amount of greenhouse gas (GHG) and carbon emission (CO2) can be reduced by 30 t-CO2eq/yr and 13t-CO2/yr, respectively. The freezer unit was using R-22 refrigerant which have ozone depleting substance (ODS) value of 0.05 and global warming potential (GWP) value of 1700 which is highly contributed to ozone depletion and global warming effect. The co-benefit of energy saving electricity consumption cost can be saved up to 9,400 RM/yr which is equivalent to approximately 19,000 kWh/yr of energy saving.
The early fluorocarbon gas detection device not only can reduce the direct and indirect impact, but it can give benefit to the economy. After all, this reduction can be achieved by having an optimum condition of this unit, for instance, a sufficient amount of fluorocarbon gas in the refrigeration system and well-functioning of the defrosting system.
3.2 Facility B
Facility B is categorized as a food commercial sector that involved the refrigeration unit. Table 4 shows the data monitoring of chiller 1 and chiller 2 for freezer room and showcase unit, respectively at Facility B. This facility was installed the fluorocarbon gas leakage detection system on two chiller unit for freezer and showcase. These two-chiller systems that are utilized R-507 as a cooling agent in order to preserve the quality of their food product.
| Phases | Chiller 1 (cold room) | Chiller 2 (showcase) | |||||
|---|---|---|---|---|---|---|---|
| Phase 1 | Phase 2 | Phase 3 | Phase 1 | Phase 2 | Phase 3 | ||
| Operating Rate (%) | 92.8 | 91.6 | 95.2 | 100.0 | 100.0 | 99.7 | |
| Total Power Consumption (kW) | 24,179.0 | 35,399.0 | 30,071.8 | 7,210.6 | 8,292.5 | 31,033.4 | |
| Daily Electricity Consumption (kWh) | 1151.4 | 1072.7 | 1307.5 | 1030.1 | 1184.6 | 1320.6 | |
| Fluorocarbon Gas Leakage (%) | 60.6 | 27.0 | 43.1 | 21.3 | 31.8 | 37.4 | |
| Machinery Room Temperature (oC) | 34.1 | 34.5 | 36.2 | 32.8 | 32.9 | 35.2 | |
| Liquid Refrigerant Temperature (oC) | 33.9 | 33.0 | 34.7 | 32.4 | 34.7 | 36.2 | |
| Discharge Temperature (oC) | 71.2 | 70.2 | 72.7 | 92.3 | 69.1 | 103.3 | |
| Suction Temperature (oC) | 15.9 | 13.9 | 14.2 | 8.16 | 7.1 | 10.3 | |
3.2.1 The scenario of refrigerant leakage
Chiller 1(Cold Room)
During Phase 1, the fluorocarbon gas leakage value on Chiller No.1 of cold room was 60.6% which is considered high leakage rate (Table 4). This data is indicating the normal working operation condition of fluorocarbon gas leakage of this chiller unit. Meanwhile, the electricity consumption of this phase was assumed as the average electricity consumption before early detection of fluorocarbon gas leakage. The service contractor for this facility was advised to repair the leakage point and fluorocarbon gas was recharged for this unit to evaluate the difference in electricity consumption for the next Phase.
For Phase 2, the leakage measurement was carried out after countermeasures action on Week 6. By repairing leakage point and recharging of 45 kg fluorocarbon in the Chiller No.1, the leakage of fluorocarbon gas shows significantly reduced from 60.6–27.0%. At the same time, electricity consumption also shows 6.8% of reduction and the suction temperature also reduce from 15.9 ˚C to 13.9 ˚C. Figure 8 shown the trend of fluorocarbon gas leak incidence and electricity consumption before and after recharge. The graph shown the difference in the oscillation trend of the incidence of fluorocarbon gas leak and electricity consumption before and after the fluorocarbon gas recharged. In addition, due to still short in fluorocarbon gas amount, the straight line of the green and blue line can’t be achieved.
Although countermeasure was carried out previously, unfortunately, in Phase 3, the electricity and rate of operation are significantly increased from 1072.7 kWh to 1307.5 kWh and 91.6–95.2%, respectively. This situation was indicating the reoccurrence of fluorocarbon gas leakage on Chiller No. 1 that raised from 27.0–43.1%. The reoccurrence of this incidence can be assumed due to the other point of leakage area at Chiller No. 1. Thus, the service contractor has again been suggested to repair and recharge the leaking point of fluorocarbon gas in order to achieve additional energy saving and stable operation of this unit.
Chiller 2 (Showcase)
The leakage of fluorocarbon gas on Chiller No.2 of showcase during Phase 1 was observed at the low level (21.3%) indicate that the fluorocarbon gas was at a sufficient level. However, this unit was operated under abnormal condition due to the 100% of operation rate. Commonly, compressors of Chiller No.2 automatically shut off when it achieved a certain temperature setting and defrost operation. This case however, it shows that the compressor is running 24 hr nonstop and possibly related to low-pressure switch or failure in setting up the compressor controller. Thus, the facility manager of this facility suggested to check the low-pressure switch or the setting of the compressor controller and adjust the compressors to shut off at the present level of pressure.
Early response time is important to reduce the direct impact of the fluorocarbon gas leakage and indirect impact from electricity consumption. This is because the abnormality of the showcase condition is continuing until Phase 3. If no countermeasure is been taken for this Chiller No. 2, major problem will be occurred in the future. According to the facility manager, this abnormal condition is rising due to two main issues. First, this chiller did not have enough compressor to back up the temperature setting for the freezer room. Normally, this compressor will stop when the maximum temperature setting on the showcase is achieved. However, it will increase the temperature in the freezer room when it stops. Therefore, in order to ensure the freezer room operated at optimum condition, the compressor need to run for 24 hr for every day. Secondly, Chiller 2 only operating using one condenser fan. This situation will cause fluorocarbon gas purge automatically when the pressure on the chiller system is high. According to the facility manager, countermeasure cannot be taken immediately, as the system need to cooled down first to prevent the high amount of refrigerant purge. This issue has been occurring in 4 months and the facility manager has emphasized to put the priority on the condenser fan issues.
Thus, due to the abnormality of this showcase unit, the increase in electricity consumption can be seen from 1030.1 kWh to 1320.6 kWh as the leakage of fluorocarbon gas increase from 21.3–37.4% at the Phase 1 of monitoring activity. This is because the compressor needs more effort to run together with the shortage of fluorocarbon gas. The temperature on fluorocarbon gas discharge and suction also will drastically increases, hence reduce the capacity of the equipment, in which can result more severe problem in the future.
3.2.2 Reduction Potential
The voltage usage of Facility B categorized under Tariff C1, which is for Medium Voltage General Commercial Tariff. The electricity price is 0.365 RM/kWh. Table 5 and Table 6 show the result of the reduction value for the actual reduction during the monitoring and reduction potential of chillers for cold room and showcase, respectively.
Facility B are using R-507A for both chiller unit, which is non-ozone depleting substance (ODS) but has a high value of global warming potential (GWP) (GWP of R-507A is 3985) that can contribute in global warming and climate change. During this study, by the response to fluorocarbon gas leakage the direct and indirect impact to the environment had been reduced. According to Table 5, Facility B successful reducing 180 t-CO2e/yr of GHG emission from the leakage of fluorocarbon gas. In addition, with 29,000 kWh/yr of reduction which equivalent to the 10,000 RM/yr of electricity consumption, has reduced 20 t-CO2/yr of CO2 emission.
| Actual Reduction | Reduction Potentials | |
|---|---|---|
| GHG reduction due to refrigerant leakage avoidance (t-CO2e/yrs) | 180 | 460 |
| CO2 Reduction due to energy savings (t-CO2/yr) | 20 | 90 |
| Energy Saving (kWh/yr) | 29 000 | 136 000 |
| Cost Cuttings (RM/yr) | 10 000 | 49 000 |
Besides, under normal operation of the Freezer Room, the reduction potential has been estimated to reduced 460 t-CO2e/yr of GHG emission. In addition, estimated 90 t-CO2/yr of carbon emission potentially can be reduced as 136,000 kWh/yr of energy saving can be achieved which approximately cost of electricity consumption can be saved up to 49,000 RM/yr.
| Actual Reduction | Reduction Potentials | |
|---|---|---|
| GHG reduction due to refrigerant leakage avoidance (t-CO2e/yrs) | 280 | 460 |
| CO2 Reduction due to energy savings (t-CO2/yr) | 50 | 110 |
| Energy Saving (kWh/yr) | 70 000 | 161 000 |
| Cost Cuttings (RM/yr) | 25 000 | 58 000 |
As previously mentioned, the electricity consumption of the showcase is increase during four months of the monitoring activity. Thus, the reduction was calculated by assuming the initial reading on Phase 1 of data monitoring as a baseline, due to the condition of the chiller system become more severe on Phase 3. Based on Table 6, 280t-CO2e/yr of GHG emission can be reduced by repairing the rising issue on the Chiller No. 2. Then 50 t-CO2/yr of carbon can be reduced by reducing electricity consumption which is equivalent to 70,000 kWh/yr of energy saving and 25,000 RM/yr of cost saving. By comparing the result from Table 5 and Table 6, the showcase unit has larger reduction potential than that cold room. This is because of the increase in percentage of electricity in the showcase unit (14.4%) is higher than the cold room (6.8%) during the monitoring phases.
3.3 Key issues on fluorocarbon gas management practice
Finding from this study shows that there are large different at on-site scenarios of fluorocarbon leakage and refrigeration system fault at each Facility A and Facility B. These results show improper service maintenance practices can give a negative impact to the climate also increase in electricity consumption. In Malaysia, the proper maintenance culture and practice is very poor. Whereas, the maintenance activity is only done in an emergency or severe fault of equipment, especially when refrigeration and maintenance issues are given no priority in most organization administration (Adeyemi et al., 2022). According to the Hauashdh et al. (2020), there are four key issues related with the building maintenance in Malaysia which is management, financial, technical and human resources. All these issues can be observed from this study.
The first key issues is human resource problems, that came from a lack of human skills and an inability to complete tasks effectively (Hauashdh, Jailani, Abdul Rahman, et al., 2020). These issues can be seen at Facility A, where the insufficient of fluorocarbon gas occur due to malpractice of service technician by proposedly emit the fluorocarbon gas from the refrigeration equipment in order to resolve the frost accumulation near the compressor. In order to remove frost accumulation in the refrigeration system, sufficient amount of fluorocarbon gas are needed. The defrost activity could not work effectively if refrigeration system have low temperature of fluorocarbon gas (Kim et al., 2013; Badri et al., 2021; Mahvi et al., 2021). It shows that the hired service technician at Facility A is lack of skill and knowledge on the best practice of fluorocarbon gas management and refrigeration system. According to the Hauashdh et al (2020), Malaysia is lack of expert for the building maintenance especially on RAC system (Hauashdh, Jailani, Abdul Rahman, et al., 2020). However, Malaysia has a total of 19,880 certified technicians for RAC up to 2022 (DOE, 2022). These technicians were provided with sufficient training under program namely Certification Service Technician Program (CSTP) for refrigeration and air-conditioning system. The training program was carried out only at the authorized training center (ATC) endorsed by the Department of Environment (DOE), Malaysia. All service technician that pass the training program will be certificated by the DOE (Nazif et al., 2022). Unfortunately, there are many active RAC service technicians out there are not certified. They are normally hired by the consumers because of their cheaper servicing charged compared to certified service technician. Awareness program to educate consumers in hiring certified RAC technician is required and collaborations among all stakeholders in the RAC equipment cycle needed.
Hired unskilled service technician is related with the key issues under management and financial. In Malaysia, the most of top management chose to hire unskilled service maintenance technicians. This is because, unskilled service maintenance technician provides lowest tender cost compared to certified technician (Ali et al., 2016; Hauashdh, Jailani, Abdul Rahman, et al., 2020). According to the Hauashdh et al. (2022), the organization need to assess the competency of the service technician with high level of transparency and integrity first before hired rather than the cost (Hauashdh et al., 2022). The competent service technician will be able to solve the complicated fault on the refrigeration system and conduct the maintenance activity in sustainable way to reduce the climate impact from fluorocarbon gas leakage also electricity consumption. Besides, top management of an organization often give a late response time to execute the maintenance or prevention measure to malfunction of refrigeration equipment. These issues can be observed at Facility B, on Chiller No. 2 for showcase unit. As previously discussed, the abnormality of Chiller No.2 was observed since Phase I of monitoring, but due to late approval from the top management to conduct the service maintenance or preventive measure at the early stage worsen the condition of Chiller No.2, where the leakage rate of fluorocarbon gas increased and thus, increasing electricity consumption at Phase 2 and Phase 3. According to the facility manager at Facility B, any major service maintenance activity that requires high cost most likely be repaired for the next cycle of budget maintenance allocation. Most of the organization in Malaysia are facing this issue. Therefore, top management of each facility need to have a standards method to determine the required budget accurately.
Another reason that can be cause late respond from the top management, there is unavailable real-time data from inside of the refrigeration system. The real-time data monitoring can help to report the fault accurately (Hauashdh et al., 2022) and to support the application for ad-hoc maintenance budget. Most of service technician in Malaysia are using direct method such as fluorescent detector, electronic detector, and bubble detector to detect fluorocarbon gas leakage. This method is not accurate as indirect method that used sensor to detect the fault of refrigeration system from inside and provide real-time data monitoring of the system. Having such information and communications technology (ICT) tool, will help facility manager and service technician to detect the accurate fault and provide an early response time on the fault (Hauashdh, Jailani, & Rahman, 2020; Adeyemi et al., 2022; Hauashdh et al., 2022). According to the Adeyemi et al (2022), it is incredibly difficult to accurately maintain and take an early action of the system in the absence of real-time data (Adeyemi et al., 2022). Improper service maintenance practice and late response time will cause inefficient of refrigeration system, as well as can give a significant impact on energy efficiency. Since this study used real-time monitoring data, the accurate prevention measure from the facility manager or service technician has been made. For example, at Facility A (Chiller No. 1) service technician has taken early response time to detect the leakage at the piping on refrigeration system and recharged fluorocarbon gas with optimum number based on the real-time monitoring data. Then, reduction of energy consumption can be observed from 1151.4 kWh to 1071.7 kWh after recharge fluorocarbon gas. However, due to the management and financial issues, the early response time at Facility A and Facility B (for Chiller no. 2) cannot be conducted. This study also shown huge potential reduction for direct and indirect emission that can be achieved by both facility if accurate and early response time has been taken by facility manager or service technician (Refer Table 3, Table 5 and Table 6). The results from the real-time monitoring data shows accurate and early response time of the refrigeration system can reduce the direct and indirect impact to the climate.
Furthermore, having an ICT tool can make it easier to report the fluorocarbon gas emission. According to the Malaysia update on the National Determine Contribution (NDC) commitment to the United Nations Framework Convention on Climate Change (UNFCCC), GHG emission from hydrofluorocarbon (HFC) will be added into the next reporting document. From recent Malaysia’s Third Biennial Update Report 2020, emission from RAC sector (2F1) was categorized under the Industrial processes and product used (IPPU), category 2F (Product Uses as Substitutes for ODS). From the report, emission from HFC only reported from mobile air conditioning category (2F1b). There are no data on stationary refrigeration and air conditioning category (2F1b) due to lack of data (refer Fig. 9). According to the Fernando (2021), Malaysia is facing a pressure in GHG reporting due to lack of support and transparency (manipulation or data loss) of reported data from the industry. Although some businesses have included GHG emissions in their yearly reports, GHG reporting is still done on a voluntary basis, making it challenging to collect accurate data (Fernando et al., 2021). Therefore, from the real monitoring data it can be extracted to reporting the accurate direct and indirect emission from the stationary RAC sector. Where, non-transparency data can be avoided and available to track the emission trend.
Nonetheless, in order to address all these significant problems and improve of Malaysia's management of fluorocarbon gases, the Environmental Quality (Refrigerant Management) Regulation 2020 must be strengthened. The precise set of guidelines is required to support the law because it is too general, and lack of a comprehensive management procedure to consumers. In Japan, the Act on Rational Use and Proper Management of Fluorocarbon are covered detail preventive measure on fluorocarbon gas emission at whole lifecycle. This act also required consumers to conduct inspection of RAC equipment regularly and report the leakages amount to the government when exceed 1000t-CO2 eq. (Ohm et al., 2017; Kawagishi et al., 2019). This act also been supported by different guidelines which include the detail procedure for each stage of lifecycle, for instance JRA GL-01 (inspection and repair fluorocarbon leakage), JRA GL-02 (fluorocarbon filling) and JRA GL-14 (prevention of the refrigerant leakage). Since this study shows Malaysia has poor maintenance culture and practice, so the needs to have a comprehensive guideline for service technician is needed. The Malaysia government can collaborate with others developed country, such Japan to adopt the guideline for Malaysia.
Additionally, including the electricity consumption in this study is part of co-benefit in refrigeration system. This approach had offers a way of not compromising on economic growth while still able to take the environmental aspect into account (Mayrhofer & Gupta, 2016). In other word, co-benefit is a win-win strategy approach (Miyatsuka & Zusman, 2009) between economic, social, the environment and institutional studies filed (Mayrhofer & Gupta, 2016). In Malaysia, fluorocarbon gas is handled by a separate agency or organization which tend to manage separately. Thus, fluorocarbon management is less interest from others where the money value in saving is not visible that more visible on environmental saving. So, it suggested pairing with monitoring value saving like energy saving in order to attract attention especially from the commercial and industrial sector especially who involved in refrigeration and air conditioning sector.
This study involves ICT tool to detect early fluorocarbon gas leakage on refrigeration equipment for the purpose of determine the scenario of fluorocarbon gas leakage management and estimate reduction potential of carbon as well as GHG emission. Finding from four months of monitoring activities at the cooling facilities was concluded that:
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The scenario of the refrigerant leakage at Facility A and Facility B is different in term of condition of the refrigeration unit, response rate and fluorocarbon gas leakage rate.
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Each facility can achieve huge reduction potential on carbon and greenhouse gas (GHG) emission also co-benefit in energy saving when the refrigeration equipment is functioning in optimum condition.
In overall, early fluorocarbon gas leak detection device is a good technology that needs to be implemented in the commercial and industrial sector. Whereas this device can reduce the environmental impact due to the carbon and GHG emission. However, installing this device only applicable for early detection of fluorocarbon gas. Without having proper fluorocarbon gas management and service maintenance practice, the environmental impact would not be reduced. Thus, for the future study, there is a need to have proper inventory and guideline for technician who handling the refrigerant in order to expose to best practice in fluorocarbon gas management in Malaysia. This is because consumers and service maintenance technicians who are extensively involved in middle steam and downstream lifecycle FC gas management require specific guideline (Nazif et al., 2022) to level up the service maintenance practice and reduce the direct as well as indirect emission to the environment.
Acknowledgement
Appreciation goes to Nanba Co., Ltd. and Mitsubishi UFJ Morgan Stanley Securities Co., Ltd. for making this research possible. This paper is based on results obtained from a project, JPNP11013, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). The output of this paper will serve to UTM vote number: R.J130000.7301.4B704 and vote number: R.J130000.7801.5F221.
Fundings
This work was supported by New Energy and Industrial Technology Development Organization (NEDO) [JPNP11013]. Dr. Shazwin Mat Taib has received research support from anba Co., Ltd. and Mitsubishi UFJ Morgan Stanley Securities Co., Ltd. for making this research possible.
Competing Interests
The authors have no relevant financial or non-financial interest to disclose.
Author Contributions
All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Nurul Nazleatul Najiha Mohd Nazif, Shazwin Mat Taib, Mohd Fadhil Md Din, Nurfarhain Mohammed Rusli, Norasikin Saman Sakiko Nogoshi, and Kozo Sakaguchi. The first draft of the manuscript was written by Nurul Nazleatul Najiha Mohd Nazif and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Consent to Publish
This manuscript is the original work of the authors, and all authors agree to publish in the ESPR. The manuscript was prepared as consulted in the Guide for Authors.
Consent to Participate
Not applicable
Ethical Approval
This manuscript has not been published elsewhere, accepted for publication elsewhere or under editorial review for publication elsewhere by any authors. The manuscript also has not been submitted to a preprint server prior to submission on ESPR
Availability of data and materials
The data that support the findings of this study are available from Nanba Co., Ltd. but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of Nanba Co., Ltd..
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