Low Global Warming Potential Research Articles

Study on the inhibition of lubricating oil in conjunction with a flame retardant on the flammability of propane

As the key part of the refrigeration systems, heat pump systems, and Organic Rankine Cycle (ORC) systems, most working fluids with low global warming potential (GWP) are flammable. This paper proposed a novel method called indirect inhibition to mitigate their flammability to enhance the applicability of low-GWP working fluids. Firstly, the effect of lubricants oil, indirect flame retardants (IFR), and mixtures of the two on the flammability of propane were investigated. The experimental results showed that lubricating oil promoted the combustion of propane to a certain extent. The introduction of indirect flame retardant (CP-52) weakened the combustion intensity of propane. The lubricating oil, in conjunction with a flame retardant, could inhibit the combustion of propane. Secondly, the effects of the indirect flame retardant and mineral oil on the flammability of propane were theoretically analyzed using density functional theory (DFT). The theoretical calculation results showed that the ability of IFR to capture reactive free radicals was comparable to that of traditional flame retardants. The research results are of great significance for improving the safety of the cycle system and reducing the risk of accidents.

Environmental Benefit Assessment of Second-Life Use of Electric Vehicle Lithium-Ion Batteries in Multiple Scenarios Considering Performance Degradation and Economic Value.

Second-life use of electric vehicle lithium-ion batteries (LIBs) is an inevitable trend; however, battery performance degradation increases environmental loads. This study evaluated the life cycle environmental impacts of second-life use of LIBs in multiple scenarios, considering performance degradation and economic value. The results showed that a component replacement rate of retired LIBs below 50% made the batteries worthy of repurposing. Reusing whole packs of retired LIBs was better than using only cells or modules owing to the environmental loads from diagnosis, disassembly, replacement, and test processes. The battery energy density and performance degradation significantly affect the maximum return on the environmental input. Compared with lithium iron phosphate (LFP) batteries, new lithium nickel manganese cobalt oxide (NMC) batteries, or lead-acid batteries, using retired NMC-811 batteries with capacities as low as 60.7% for energy storage systems to store wind electricity rather than hybrid or photovoltaic electricity, had substantial environmental benefits, including a low global warming potential. Considering the costs of battery recycling, labor, and electricity, using whole packs of retired LIBs could simultaneously achieve high economic and environmental values in energy storage and peak shaving scenarios.

Theoretical evaluation of energy, exergy, and minimum superheat in a high-temperature heat pump with low GWP refrigerants

Suitable low global warming potential (GWP) refrigerants that conform to F-gas regulations are fundamental to the operation and future development of high-temperature heat pumps (HTHPs) used for industrial processes and waste heat recovery. This paper presents the results of a theoretical simulation to investigate a range of low-GWP refrigerants and their suitability to supersede refrigerants HFC-245fa and HFC-365mfc. A steady-state thermodynamic model of a single-stage HTHP with an internal heat exchanger (IHX) was developed to assess system cycle characteristics and performance at temperature setpoints at 60 and 70 °C heat source, 90 and 140 °C heat sink, at 30 and 70 K lift. This study focuses on energetic and exergetic efficiencies within the system and the impact of regulating superheat to optimise performance. Based on energetic and exergetic theoretical results, a trade-off between COP, VHC, and exergetic efficiency indicates HCFO-1233zd(E) and HFO-1336mzz(Z) as the most likely replacements for HFC-245fa and HFC-365mfc respectively. The refrigerant HC-601, followed by HFO-1336mzz(Z) and HCFO-1233zd(E), exhibited the lowest exergetic destruction within test conditions. Mapping the minimum superheat indicated optimum performance for HCFO-1233zd(E) between 5 and 8 K and HFO-1336mzz(Z) between 17 and 22 K, depending on temperature lift. Validation of the theoretical results with experimental data indicates that simulated COP closely matches empirical values. This work provides a method to optimise refrigerant selection in HTHPs based on operational indicators to maximise overall system performance.

Study on biogas production from coffee wastes and cow-dung fermentation and its use towards reducing emissions from coffee roasting

The production of high-quality coffee for export is an important industry in Indonesia. However, coffee processing produces unavoidable waste and emissions to the environment; 1 kg of cherry beans (CB) needs 3 kg of water for processing (2 kg for CB selection by floating, 1kg for wash-fermentation). One kg CB generates several waste and product streams: cherry skin (44%), beans (20%), parchment (5%), pulp (4%), silverskin (0.5%), and volatiles (26.5%). This study utilized the wastewater from the washed-coffee processing such as fermentation wash water and coffee pulp. The materials were mixed with cow dung from local farms for anaerobic processing in a one-gallon digester. This research took into consideration three variations: cow dung mixed with water in the same amount (1:1); cow dung and fermentation washing wastewater (1:1); and cow dung and pulp (1:1). The resulting biogas was analyzed with gas chromatography for comparison. Biogas yield was used to estimate the potential for supplying heat and electricity for use in the coffee roasting process. Alternative energy sources were also considered in the following combinations: biogas-electricity (solar panels) and LPG-electricity (fossil). A life cycle assessment was performed on scenarios to calculate global warming potential (GWP). This study will be used as a pilot project toward a zero-waste and zero-emission coffee industry. The scenario with the lowest GWP can be used as a reference for the sustainability of coffee production.

Air Conditioning Heat load Analysis of a Cabin

Abstract: Air conditioning, often abbreviated as A/C (US), AC (US), or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as "comfort cooling") and in some cases also strictly controlling the humidity of internal air. Air conditioning can be achieved using a mechanical 'air conditioner' or alternatively a variety of other methods, including passive cooling or ventilative cooling. Air conditioning is a member of a family of systems and techniques that provide heating, ventilation, and air conditioning (HVAC). Heat pumps are similar in many ways to air conditioners, but use a reversing valve to allow them to heat and also cool an enclosed space. Air conditioners, which typically use vapor-compression refrigeration, range in size from small units used within vehicles or single rooms to massive units that can cool large buildings. Air source heat pumps, which can be used for heating as well as cooling, are becoming increasingly common in cooler climates. According to the International Energy Agency (IEA), as of 2018, 1.6 billion air conditioning units were installed, which accounted for an estimated 20% of electricity usage in buildings globally with the number expected to grow to 5.6 billion by 2050. The United Nations called for the technology to be made more sustainable to mitigate climate change and for the use of alternatives, like passive cooling, evaporative cooling, selective shading, windcatchers, and better thermal insulation. CFC and HCFC refrigerants such as R-12 and R-22, respectively, used within air conditioners have caused damage to the ozone layer, and HFC refrigerants such as R-410a and R-404a, which were designed to replace CFCs and HCFCs, are instead exacerbating climate change. Both issues happen due to the venting of refrigerant to the atmosphere, such as during repairs. HFO refrigerants, used in some if not most new equipment, solve both issues with an ozone damage potential (ODP) of zero and a much lower global warming potential (GWP) in the single or double digits vs. the three or four digits of HFCs.

Propane-isobutane mixtures in heat pumps with higher temperature lift: An experimental investigation

The shift towards renewable energies leads to an increased interest in heat pumps, not only for floor heating at temperatures around 40 °C, but also for providing hot water at higher temperatures (>60 °C). To reach the goal of a climate neutral process, it is important to use working fluids with a low global warming potential (GWP). Zeotropic mixtures are discussed to potentially increase the coefficient of performance (COP) of a heat pump compared to pure fluids. The present work experimentally analyses a compression heat pump process of such fluids; five mixtures of propane (R290) and isobutane (R600a) are investigated here. The influence of composition, compressor frequency, inlet temperature of the working fluid into the evaporator and the inlet temperature of the secondary fluid water into the condenser are researched. Besides the COP, the destroyed exergy in the components are evaluated, to find the most relevant losses. It is shown that the COP for a temperature lift of 33 K are above 3 for the mixtures, while at a higher temperature lift of 53 K the COP is around 2. Furthermore, a strong impact of the overall compressor efficiency on the process was found. The results show that the advantage of the zeotropic mixture within the heat exchangers is often limited by their low contribution to the total specific exergy destruction compared to the compressor. The compressor efficiency changes with the composition, due to composition dependent pressure and density variations. The often-neglected changes in electro-mechanical losses get important, when the pressure ratios are changing with composition, as shown experimentally.

Refrigerant selection from an economic and TEWI analysis of cascade refrigeration systems in Europe based on annual weather data

Due to environmental concerns and increasingly stringent regulations, refrigerants with low global warming potential must be used in cascade refrigeration systems. However, identifying the most suitable combination of refrigerants is still a major challenge. Therefore, a methodology for selecting refrigerant combinations for cascade refrigeration systems dedicated to freezing applications is presented. A bilevel optimization procedure approach based on a thermodynamic 0D-steady state model and weather data at different locations in Europe (i.e. France, Germany and Spain) has been developed. The system is optimized in terms of the coefficient of performance on an hourly basis as the lower level task and the total annual cost as the upper level task. The results are analyzed with respect to the annual cost and the corresponding Total Equivalent Warming Impact (TEWI). In total, 36 different low GWP refrigerant pairs were studied for a cascade refrigeration system with an imposed cooling load of 100kW. The results of the analysis show that dimethyl ether and R161 have the best performance for the high temperature circuit. However, close performances were obtained with R717 and R152a. For the low temperature circuit, similar results were observed for R41, R170 and R744. For the R161/R744 pair, the optimal annual cost and corresponding TEWI are 141 285€year−1 and 3001t, 108 858€year−1 and 2459t, 105 179€year−1 and 533t for Berlin, Madrid and Paris, respectively. Furthermore, the study shows that the optimal refrigerant selection of the investigated refrigerants is robust for the cooled space temperature and the location of the cascade refrigeration system, as no significant change of the TEWI and the total annual cost ranking of the individual refrigerants is observed.

Experimental Analysis of Local Condensation Heat Transfer Characteristics of CF3I Inside a Plate Heat Exchanger

Due to its low global warming potential (GWP) and good environmental properties, CF3I can be a suitable component of refrigerant mixtures in the field of refrigeration and air conditioning. In this work, the local condensation heat transfer characteristics of CF3I were experimentally investigated in a plate heat exchanger (PHE). The condensation heat transfer experiments were carried out under conditions of vapor qualities from 1.0 to 0.0, at saturation temperatures of 25–30 °C, mass fluxes of 20–50 kg/m2s, and heat fluxes of 10.4–13.7 kW/m2. Local heat transfer coefficients were found to vary in both the horizontal and vertical directions of the plate heat exchanger showing similar trends in all mass fluxes. In addition, the characteristics of local heat flux and wall temperature distribution as a function of distance from the inlet to the outlet of the refrigerant channel were explored in detail. The comparison of the experimental data of CF3I with that of R1234yf in the same test facility showed that the heat transfer coefficients of CF3I were comparable to R1234yf at a low vapor quality and a mass flux of 20 kg/m2s. However, R1234yf exhibited a transfer coefficient about 1.5 times higher at all vapor qualities and a mass flux of 50 kg/m2s. The newly developed correlation predicts well the experimentally obtained data for both CF3I and R1234yf within ±30%.

Selection of a suitable working fluid for a combined organic Rankine cycle coupled with compression refrigeration using molecular approaches

A vapor compression refrigeration cycle (VCRC) driven by an organic Rankine cycle (ORC) is an alternative to generating cold through a renewable energy source such as solar, residual thermal, and geothermal energy. The system analyzed in this work consists of an ORC coupled with a VCRC by a shaft where each one of the cycles uses an independent working fluid. This manuscript analyses 8 working fluids resulting in 16 combinations. These fluids include common refrigerants, such as R22 (HFCF) and R134a (HFC), with other low or null global warming potential (GWP) substances, such as hydrocarbons (HCs) and hydrofluoroolefins (HFOs). The PC-SAFT EOS is used as a predictive tool to obtain the equilibrium condition and thermophysical properties at each point in the cycle. The choice of the best combination of working fluids is done under the criteria that the ORC boiler and evaporator temperatures work in a range of 60.0 to 100.0 °C and −15.0 to 0.0 °C, respectively. The compressor outlet temperature, the VCR-ORC system Coefficient of Performance (COP), and the VCRC COP are the selected key parameters analyzed. The results show that the combination of n-pentane and R1233zd provide a good performance in terms of COP compared to other refrigerants.

Working fluid selection for a high efficiency integrated power/cooling system combining an organic Rankine cycle and vapor compression-absorption cycles

This paper presents the performance evaluation of several combinations of working fluids for a new heat recovery cogeneration system which combines an Organic Rankine Cycle (ORC), a Vapor Absorption Cycle (VAC) and a Vapor Compression Cycle (VCC). NH3–NaSCN is chosen as the working fluid in the VAC. Seven different refrigerants in the ORC-VCC were studied to identify the fluid that would allow the overall system to achieve a high efficiency in the tropical region. These fluids were chosen because of their low Global Warming Potential and Ozone Depletion Potential. A thermodynamic simulation allowed to set the appropriate operating conditions of the VAC. Subsequently, energy and exergy analyses showed that R717 is the appropriate working fluid for system operation in the tropical region. For this fluid, the highest values of cooling capacity, net power output, thermal efficiency, exergy efficiency and exergy destruction of the system were respectively 1205 kW, 158.3 kW, 64.32%, 39.39% and 690.4 kW for VCC evaporation temperature of 15 °C, for ORC-VCC condensation temperature of 40 °C and for ORC steam generator outlet temperature of 219.7 °C. The most exergy-destroying components are the steam generator and the ORC/VCC condenser with 57.29% and 22.58%, respectively.

Design and Development of R32a and HFO-1234yf Refrigeration blend in Air conditioning System

Abstract: Refrigeration and air-conditioning systems become an integral part of modern society. Electricity-driven vapour compression systems have been dominating the heating, ventilation, air conditioning and refrigeration (HVAC&R) industry. The working fluids of these systems often contribute to the environmental issues in the forms of direct and indirection emissions. Pure refrigerants are often limited inmeeting criteria such as efficiency, flammability, toxicity, and compatibility. Meanwhile, refrigerant mixtures offer flexibilities to tune these criteria, This paper will review the status worldwide on technical and policy search for next-generation refrigerants with both low Global Warming Potential (LGWP) and low Life Cycle Climate Performance (LCCP) with particular focus on R410A replacement for unitary A/C & H/P. R32 and the HFO blends offer potential solutionsbut all involve tradeoffs among Global Warming Potential (GWP), efficiency, safety, and cost. With the U.S. mandating new higher regional efficiency standard taking effect January 2015, there is even more pressure in finding a LowGWP refrigerant solution that is affordable and can sustain efficiency and reduce charge requirement. This paper focuses more on R32 as the available data for HFO blends is limited. And Mixing of both R32a and HFO-1234yf in Ac To Study the performance two different next generation refrigerants R32 and Hfo-1234yf.To determine most promising refrigerant blend for air conditioning system test observe, anaylize and compare result obtained with conventional refrigerant. To determine impact of R32 and HFO-1234yf refrigerant as a replacement of R410A

CARACTERISTICILE DE TRANSFER DE CĂLDURA ALE UNUI VAPORIZATOR CARE ECHIPEAZA O CENTRALA DE TRATARE A AERULUI DESTINATA UNUI DEPOZIT DE SEMINȚE DE CEREALE

In this paper the evaporator from the air handling units (AHU) is being studied, this being connected to an air conditioning installation with mechanical compression of vapors, existing within the Thermodynamics department. In a previous analysis, the heat exchanger (HEX) was checked to see if it complied with the cooling capacity relative to the heat exchange surface by finding the specific criteria equations. A follow-up to the previous article is to calculate based on the thermodynamic cycle, what happens if the refrigerant is replaced with other new refrigerants in the field of air conditioning in order to improve the performance of the air conditioning system (ACS), finding the refrigerant with a low Global warming potential (GWP) and with an appropriate flammability class. The moisture content of seeds is one of the most important storage parameters affecting their quality. In order to obtain the desired effect, the temperature and humidity of the air must be maintained in the warehouse with an air treatment unit. In this study, it is desired to replace the refrigerant and preserve the refrigerating power from the evaporator, by changing the degree of sub-cooling from the condenser. Due to the fact that the temperature in the ambient environment changes substantially during a calendar year and the condenser of the air conditioning installation has the same configuration, thus the decrease in the ambient temperature will result in the appearance of the sub-cooling process and an increase in the performance of the installation.

Life cycle assessment of routinely used endoscopic instruments and simple intervention to reduce our environmental impact

ObjectivesGI endoscopy units represent the third largest producers of medical waste. We aimed to determine endoscopic instrument composition and life cycle assessment (LCA) and to assess a sustainability proposal based...

Estimation of thermodynamic properties of environmentally friendly new-generation R515B and R450A as an alternative to R134a

In the analysis of vapor compression refrigeration systems, simple and effective mathematical formulas are required to determine the thermodynamic properties of refrigerants. This study aims to determine the thermodynamic properties such as enthalpy, entropy, and specific volume of environmentally friendly new-generation refrigerants (R515B and R450A) with low global warming potential using gene expression programming (GEP). The thermodynamic properties calculated using the formulations obtained from the GEP model and the actual thermodynamic properties obtained from the REFROP software were compared. Performance evaluation criteria such as R2, root mean square error, and mean absolute percent error are in the range of 0.86 to 0.999, 0.0000285-6.489, and 0.0009-0.35, respectively, and these values are acceptable. This study offers simple and efficient formulations to calculate the thermodynamic properties of new-generation refrigerants without the need for any software. So, the simulation of cooling and heat pump systems will be greatly facilitated.

Measurement of vapour pressure, miscibility and thermal conductivity for binary and ternary refrigerant lubricant mixtures in the context of heat pump tumble dryers

Household appliances need to be both efficient and cost-effective. As a result, electrically driven tumble dryers were converted to heat pump driven ones several years ago in order to comply with energy directives, in this case in Germany. In order to increase the efficiency of heat pumps of different performance classes, the use of zeotropic refrigerant mixtures can be useful, since the temperature glide during the phase change of the refrigerant mixture can be adapted to the temperature gradients of the secondary fluids. In order to take advantage of this unique property, a refrigerant mixture selection was carried out by a screening procedure using REFPROP. Within the investigation presented here, two different zeotropic refrigerant blends, propane (R290)/dimethyl ether (DME or RE170) (30 wt.%/70 wt.%) and R152a/carbon dioxide (R744) (90 wt.%/10 wt.%) are focused on as substitutes with low global warming potential (GWP) for R134a in heat pump tumble dryers. The focus is on the interaction between the refrigerant mixtures and the respective lubricant to ensure usability in the heat pump tumble dryer. A specialised polyolefin-based (POE) lubricant was chosen for each refrigerant blend. Because the numerous combinations of possible refrigerant mixtures can lead to unanticipated challenges with oil mixtures, additional experimental investigations are necessary to ensure the compatibility of the lubricant and refrigerant mixture combination in the temperature ranges associated with the investigated application. Therefore, measurements of the vapor pressure, miscibility gaps and thermal conductivity of the refrigerant-lubricant mixture have been carried out and are the focus of this paper.

Condensation heat and mass transfer characteristics of zeotropic refrigerant mixture R1234yf/R32 inside small-scale tube: Flow patterns observation and non-equilibrium film model calculation

Minichannel heat exchanger has been more and more widely used in refrigeration industry and other fields due to its high heat transfer efficiency, lightweight and low carbon emissions and other advantages. And, the zeotropic mixture R1234yf/R32 with low global warming potential (GWP) is a promising substitute for R410A in commercial refrigeration. In this study, the experiment investigation of condensation heat and mass transfer characteristics of R1234yf/R32 in minichannel test tube (inner diameter (ID) 2 mm) were conducted. The influencing factors including mass flow rate, vapor quality, mass fraction and tube diameter on the mass transfer and heat transfer coefficient (HTC) were discussed in detailed. The flow pattern was taken during condensation experiment. Meanwhile, based on the discussion of flow pattern, thermophysical properties, tube diameter and composition variation in the liquid film and at the vapor-liquid interface, the effects on heat transfer and mass transfer during condensation were analyzed. The calculation results using the non-equilibrium film model considering the mass transfer on both the liquid and vapor sides were compared and agreed well with the experimental HTC with an average deviation of 14.9%. In addition, the heat transfer degradation coefficient (HTDC), vapor-liquid interface temperature and diffusion flux of R32 were reasonably evaluated by the calculation model, and the comparison analysis were conducted with that of ID 4 mm in the previous study.

Investigating attitudes and insights into the global warming impact of inhalers.

Inhalers are commonly used in the management of respiratory diseases. The propellants used in pressurised metered dose inhalers (pMDIs) are potent greenhouse gases and carry a substantial global warming potential. Dry powder inhalers (DPIs) are propellant-free alternatives that have fewer consequences on the environment, while being equally effective. In this study, we assessed patients' and clinicians' attitudes towards choosing inhalers that have a lesser environmental impact. Surveys of patients and practitioners were undertaken in primary and secondary care settings in Dunedin and Invercargill. Fifty-three patient and 16 practitioner responses were obtained. Sixty-four percent of patients were using pMDIs, while 53% were using DPIs. Sixty-nine percent of patients believed that the environment is an important consideration when switching inhalers. Sixty-three percent of practitioners were aware of the global warming potential of inhalers. Despite this, 56% of practitioners predominantly prescribe or recommend pMDIs. The 44% of practitioners who mostly prescribe DPIs were more comfortable doing so based on environmental impact alone. Most respondents believe global warming is an important issue and would consider changing their inhaler to a more environmentally friendly type. Many people were not aware that pressurised metered dose inhalers have a substantial carbon footprint. Greater awareness of their environmental impacts may encourage the use of inhalers with lower global warming potential.

Plasma Atomic Layer Etching of SiO2 and Si3N4 with Low Global Warming C4H3F7O Isomers

In this study, plasma atomic layer etching (ALE) of C4H3F7O isomers heptafluoropropyl methyl ether (HFE-347mcc3), heptafluoroisopropyl methyl ether (HFE-347mmy), and perfluoro propyl carbinol (PPC) having low global warming potential were investigated and developed for SiO2 and Si3N4 films. Fluorocarbons generated from C4H3F7O isomer plasmas were used to fluorinate the SiO2 and Si3N4 surfaces, and the fluorinated surface was etched using Ar plasmas in the following step. The HFE-347mmy produces the lowest F 1s/C 1s ratio or carbon-rich fluorocarbon. The chemical sputtering threshold energy of Si3N4 was found to be 5–10 V lower than that of SiO2. The ALE window was observed in the range of 50–60 V for all isomers, and the EPC of SiO2 was determined to be 2.1, 1.8, and 5.2 Å/cycle for HFE-347mcc3, HFE-347mmy, and PPC, respectively. The EPC of Si3N4 is higher than that of SiO2 in all precursors. The highest etch selectivity of SiO2 and Si3N4 over poly-Si was achieved with HFE-347mmy as high as 103 for SiO2 to poly-Si and 189 for Si3N4 to poly-Si. This study demonstrates that C4H3F7O isomers can help reduce global warming by replacing the conventional perfluorocarbons and achieving high selectivity of SiO2 to poly-Si and Si3N4 to poly-Si.

Drop-In Replacement of R134a in a Household Refrigerator with Low-GWP Refrigerants R513A, R516A, and R1234ze(E)

This study proposes the experimental evaluation of alternative refrigerants with low global warming potentials (GWPs) such as R1234ze(E), R513A, and the mixture R516A as a drop-in replacement for R134a in a domestic refrigerator with a volumetric capacity of 513 L. Initially, the optimal charge for each refrigerant was defined based on the minimum energy consumption of the refrigerator, then the thermal and energy performance of the refrigerator was evaluated. Finally, a total equivalent warming impact analysis (TEWI) was performed. The main results indicated that the optimal charge of the alternative refrigerants was below that corresponding to R134a (105 g), of which R516A (86 g) presented the greatest charge reduction. Regarding the average temperature of the refrigerator compartments, very adequate thermal conditions were observed; thus, the alternative refrigerants showed very similar conditions to R134a. For the coefficient of performance (COP) and considering R134a as a reference, it was observed that R513A presented the greatest reduction of around 28%, while R1234ze(E) showed an increase of 13% in relation to R134a. Finally, the TEWI analysis showed R1234ze(E) as the refrigerant with the least impact.

The environmental impact of inhaler replacement: A carbon footprint and economic calculation of the National Database of Health Insurance Claims in Japan.

Drugs are a major source of greenhouse gas (GHG) emissions from healthcare systems. Pressurized metered-dose inhalers (pMDIs) have raised concerns over their environmental impact due to GHG emissions. Evaluations and reduction strategies for GHGs have been primarily studied in Europe, but not in other regions, including Japan. Therefore, our objective was to calculate the carbon footprint of inhalers in Japan and evaluate their reduction scenarios. Using the National Database of Health Insurance Claims, our analysis was conducted on inhaler prescriptions in Japan for the fiscal year of 2019. We calculated the number of inhalers used, GHG emissions, and total costs. Next, we simulated the environmental and economic impacts of three reduction scenarios: the first scenario replaced pMDI with dry power inhalers, followed by age-based replacements. In the last scenario, we replaced pMDI with a propellant with a lower global warming potential. All inhaler-related GHG emissions were 202 ktCO2e, of which 90.9% were attributed to pMDI use. Scenario analysis demonstrated that replacing 10% pMDI with DPI would reduce emissions by 6.7%, with a relatively modest increase in cost; substituting 10% of pMDI used by adults (excluding children and older adults) with alternative inhalers would reduce emissions by 6.1%, with a 0.7% increase in cost; and, replacing 10% of pMDI propellants with lower global warming potential would reduce emissions by 9.3%. Selecting appropriate inhalers can mitigate GHG emissions in Japan, but its impact will be less than in other countries. Nevertheless, collaborative efforts between physicians, patients, and pharmaceutical companies are necessary to reduce GHG emissions.