Last month, the International Electrotechnical Commission (IEC) released their draft proposal to raise the maximum charge size for flammable refrigerants in commercial self-contained cases from 150 grams to 500 grams. This marks another significant step forward for the NASRC's work to change standards to increase the maximum charge limit for R290 use in self-contained equipment, one of the goals of the Codes & Standards progress group.
Why Does a Higher Charge Limit Matter?
According to Marek Zgliczynski, Chair of the IEC subcommittee responsible for developing the proposal, this standard, known as IEC60335-2-89, "is the basis for all regional and national product standards for household or similar commercial-type applications.” The proposed change will "increase the maximum allowable charge of flammable refrigerants in [commercial self-contained display cases], while maintaining the same safety level of the present standard with 150 grams," explains Zgliczynski.
The current charge limit of 150 grams is severely limiting the use of propane self-contained systems in the US. While 150 grams of propane is adequate for small-to-medium-sized display cases, the larger display cases that are prevalent in this country need more propane for cost-effective operation
The main concerns about higher propane charge sizes relate to safety, as is to be expected with an A3 refrigerant. The specific requirements in the IEC’s proposal ensure that cases with 500 grams of propane are as safe as those with 150 grams. These requirements include the following:
- The refrigerant circuit must be hermetically sealed and mechanically protected;
- Construction cannot cause excessive vibrations of circuit piping;
- Airflow is required to avoid flammable concentration beyond the boundary of appliance, certified with a special leak test; and
- Appliance must be installed in a room with a floor area not less than the marked minimum room area.
The proposal has to pass two stages of voting, the first of which will close mid-July. The IEC is accepting comments from stakeholders at http://www.iec.ch/comment/ until that time. The NASRC will provide instructions to members on how to submit comments and template language that members may use to express support for the IEC proposal.
If the draft proposal receives a two-thirds majority in the first vote, it will move to the second and final stage of voting. If the proposal passes the final stage, a new edition of IEC60335-2-89 will be published in early 2019.
Zgliczynski noted that, "this new standard will allow for systems manufacturers to comply with present and future regulations phasing out high-GWP refrigerants globally in this specific market segment."
As state and federal governments ban or phase down high-GWP HFC and HFO-blend refrigerants, commercial refrigerant end-users will need access to technologies that use refrigerants with GWPs below 150. Propane self-contained systems show great potential to meet much of that need. The main hurdle preventing the widespread use of this technology in the US is the slow pace of ASHRAE and UL in revising their standards. The IEC proposal, if passed, is the stimulus that the US standards organizations need to get them moving in the right direction. To encourage ASHRAE and UL to work with the NASRC to speed up their timelines, sign the NASRC petition for faster revision of codes and standards.
NASRC Call to Action
The NASRC is calling on industry stakeholders to contribute to this initiative with the following activities: