R-32, the next step in reducing GHG in HVAC in Brazil

Refrigerants are very important in contemporary society, although many do not fully understand their role. These substances are essential in thermal cycles for generating “cold,” whether to cool or freeze food and increase its “shelf life,” or to cool an environment, or even to cool an industrial process.

The refrigerants that are most memorable to some generations are CFCs (Chlorofluorocarbons), compounds that were banned due to their high ODP (“Ozone Depletion Potential”) and consequent high exposure capacity to the ozone layer by the Vienna Convention in 1987. Brazil ratified the national ban on this type of fluid in 1990 and stopped 100% of its production in 2010.

HCFCs (Hydrochlorofluorocarbons) were adopted to replace CFCs, substances that are relatively close to CFCs molecularly and have a lower ODP, but not zero. The best-known HCFCs are R-22 and R-141b, both widely used in air conditioning and refrigerator equipment. However, in September 2007, the signatory countries of the Montreal Protocol decided to ban HCFCs by 2040, due to their still high environmental impact. The goal was to ban HCFCs by 2025, 97.5% by 2030 and finally 100% by 2040. This is one of the reasons why it is extremely rare to find air conditioning equipment with R-22 on the market today and why, soon, equipment with this type of gas will become obsolete, since it will be increasingly difficult to perform their maintenance. (hydrofluorocarbons), substances that do not contain chlorine in their composition. These fluids, in general, have practically zero ODP levels, but have high levels of greenhouse effect potential (GWP, “Global Warming Potential”) to be considered acceptable in the current state of climate change. One of the best-known and most widely used fluids in the HFC class is R-410A, a mixture of R-32 and R-125.

A recent Kigali Amendment to the Montreal Protocol, from 2016, also provides for a reduction in the use of HFCs. This is likely due to the high GWP of these gases, something that needs to be addressed promptly with the worsening effects of climate change and the increase in the average temperature of the Earth. There are 122 countries that have already ratified this amendment, including China, but Brazil is one of the few developing countries that has not yet done so.

This leads to the risk of Brazil becoming a dumping ground for obsolete fluids. As other countries advance towards the goals of the Kigali Amendment, which also foresees a gradual reduction of HFCs by 2045 in Brazil, manufacturers may see our country as a place to “deposit” the production of HFCs not consumed in other countries.

Therefore, there is an initiative for a technological transition in the “leap-frog” format, by adopting an advanced technology, but sufficient to stop technological “dumping” in Brazil, to advance to technologies and fluids with GWP lower than 1 (CO2 has a GWP of 1 and is considered a “base” value) and zero ODP, such as the fluid R-1234ze, which is already a reality, although very costly for the Brazilian reality. This initiative was led by Kigali Network and achieved good results.

One of the criteria for the “leap-frog” is that the fluids have a GWP of less than 750, so one of the fluids chosen to be the first step is R-32, which has a GWP of approximately 677 (it varies a little according to the IPCC report considered) and which is already a reality in equipment in other countries. Its costs are similar to what we have on the market today and, technologically, it is close to R-410A, since it is part of its composition.

Equipment with this fluid is already on the Brazilian market and, on the Inmetro's equipment list, a manufacturer with the most equipment listed with this technology is Daikin. Other companies are already investing in this type of technology, but they are not yet as present on Inmetro's list. Daikin's equipment is manufactured nationally and the company has, on its Manaus site, production of 100% of the equipment of some lines with R-32, and it is already possible to find this type of equipment in retail. They are already available on the Inmetro equipment list, also with the new efficiency index, the IDRS (Seasonal Cooling Performance Index), which will replace the COP (Coefficient of Performance) or EER (energy efficiency ratio) in air conditioning equipment. an expansion. To evaluate the difference between purchasing these equipment with R-410A fluid and with R-32, retail prices will be considered without considering shipping, as this is an evaluation of a hypothetical scenario. Assuming that this hypothetical institution will have to purchase 50 pieces of 18,000 BTU/h equipment, 75 pieces of 12,000 BTU/h equipment and 25 pieces of 9,000 BTU/h equipment, the prices and IDRS considered are in the following table and following what is indicated in the tInmetro table:

For this analysis, the screening method of the GHG Protocol's “Refrigeration and Air-Conditioning Equipment” tool was used, considering that the R-410A fluid has a GWP of 2088 and R-32 of 677. Also consider, according to the specifications suggested for this method, a recycling efficiency of 70%, that the equipment load would be between 0.05 and 0.5 kg, that its lifespan would be between 12 and 15 years, that the emission factor of the equipment installation would be between 0.2% and 1% and that the emission factor for leaks would be between 0.1% and 0.5%. It also considers 2,860 hours of operation per year and an average energy cost of R$0.82/kWh.

First, it can be seen that equipment with R-32 is more efficient than its equivalents that have R-410A. Until the beginning of the second half of 2021, the average IDRS of equipment listed with R-32 by Inmetro is higher than that of equipment with R-410A. This already shows that, in addition to reducing emissions, it is a type of equipment that brings a reduction in energy consumption, which reduces its cost over time.

In this proposed scenario, there would be a reduction of approximately 7.77 tCO2e, encompassing scopes 1 and 2, and an estimated annual savings of R$22,660.00 and 27,635 kWh/year. However, there would be an additional initial investment of R$109,933 that would be paid off in 4.85 years, at which point this investment would begin to yield returns and, considering a period of 15 years, the estimated lifespan of this equipment, this investment would have an IRR (Internal Rate of Return) of 14%.

This is a conservative scenario; it is likely that many current pieces of equipment will not reach an IDRS of 6.20 and, the greater the difference in efficiency, the greater the savings and the faster the return on investment. Therefore, within this scenario and considering the values presented, a parallel can be drawn with an investment in which R$110,000 is invested and which has a return of at least R$22,000 per year. economic sectors, is among the most significant. This type of equipment is a reality and adopting it will be useful for Brazil to take an important step not only to be even more sustainable, but also to prevent us from being a depository of obsolete technologies.