Naturals a clear choice in wake of changing standards and potential bans

By Pilar Aleu, Jan 09, 2015, 16:39 3 minute reading

On 17 December Embraco hosted a webinar led by John Prall, Technical Support Engineer, regarding the proposed DOE and EPA standards and bans’ potential effect on the commercial refrigeration industry. Switching to natural refrigerants such as CO2 (R744) and hydrocarbons (R290 and R600a) is the clear choice, according to compressor manufacturer Embraco, to stay ahead of increasingly stringent regulations concerning energy efficiency and standards.

With a steadily increasing world population comes increasing energy consumption. The resulting rapid rise in CO2 concentration, recently measured at 400 ppm, is one of the culprits contributing to the planetary temperature ascending,causing ocean levels to rise and extreme atmospheric events to occur.

New DOE efficiency standards could require more than 50% energy reduction

Across the globe, nations are strengthening energy efficiency regulations, particularly related to light commercial refrigeration applications. The United States is one of the largest contributors of indirect CO2 emissions, largely due to its significant dependence on coal for its power supply. The United States Department of Energy recently proposed aggressive new energy standards for 2017.

The proposed standards pose a weighty challenge for system manufacturers. For example, the new standards could require 57% less energy consumption of an upright glass door freezer. In the webinar, Prall noted that this challenge will not be overcome by simply switching to the use of more efficient compressors and that in order to meet the requirements, manufacturers will need to take a more wholesome approach such as considering the use of more efficient refrigerants, better insulation in the units, improved doors, etc.

US could see increased f-gas bans by 2017

Regulation of fluorinated gases is also on the rise. The newly revised European Union F-Gas Regulation has just come into force at the turn of the New Year, and the EPA has also proposed a ban on certain HFCs, which is set to be approved by the end of 2015. If approved, the regulation would, by 2016, ban R507A, R404A, R407A/C/F and R134a in both new and retrofit retail food refrigeration, as well as new and retrofit vending machines.

Prall suggested that natural refrigerants, particularly hydrocarbons, are the answer to the challenge the new regulation would pose. He noted that already there are millions of light commercial refrigeration appliances using hydrocarbons and CO2, as well as millions of household refrigerators using hydrocarbons.

Hydrocarbons prove more efficient in light commercial applications

While hydrocarbons are flammable, they are also safe to work with, mostly because of the small refrigerant charge, just 5.3 ounces or the equivalent to about two or three cigarette lighters. Furthermore, Prall noted that the efficiency of hydrocarbons refrigerants saves energy and money.

Prall described three cases in which refrigerant R404A was replaced with R290 (propane) in order to measure the total equivalent warming impact (TEWI). In an ice cream chest freezer, R290 achieved a 16% energy reduction over R404A. In a medium glass door merchandiser, the refrigerant was switched to R290, the fan motors were improved, and the lights were replaced with LED lighting. The improvements to the system resulted in a 32% energy reduction. In a vertical glass door freezer, the experiment yielded a 43% reduction in energy.

Furthermore, Prall listed additional benefits of R290 in light commercial refrigeration applications, such as lower operating temperatures compared to R404A, which allow for increased efficiency and longer service life. Because the refrigerant charge is so low, R290 does not present an issue with liquid return, eliminating the need for a receiver, and there is also no refrigerant glide, which allows for simplified evaporator design, making it easy to achieve proper superheat. In addition, hydrocarbons are low cost refrigerants, and the use of hydrocarbons is well-established technology.

Prall stated that hydrocarbons could already cover most light commercial applications, though due to charge restrictions, parallel compression is required for larger commercial systems. Prall noted, however, that there is a common effort to increase the charge limit to 300-500 g in order to be able to cover all commercial applications without multiple circuits. In addition, R600a is not approved for use in vending machines under the Significant New Alternatives Policy (SNAP), though this is expected to change soon, pending the approval of an EPA proposal to expand the use of hydrocarbons in certain applications.


By Pilar Aleu

Jan 09, 2015, 16:39

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