TABLE OF CONTENTS - Everything R744

NORTH AMERICAN POLICIES: UL STANDARDS ON HYDROCARBONS AND TRANSCRITICAL CO 2
ADDRESSING NATURAL REFRIGERANT
STANDARDS
Underwriters Laboratories (UL) has developed the following
requirements for the use of flammable refrigerants,
including hydrocarbons in commercial refrigerators,
vending machines, and room air conditioners:
• UL 250 - Household Refrigerators: Supplement SA
published 25 August 2000, similar to the requirements
in IEC 60335-2-24
• UL 471 - Commercial Refrigerators: Supplement SB
published 24 October 2008, similar to the requirements
in IEC 60335-2-89
• UL 541 - Refrigerated Vending Machines: Published
requirements 30 December 2011
• UL 484 - Room Air Conditioners: Published requirements
21 October 2011, similar to the requirements
in IEC 60335-2-40
The UL standards set the following refrigerant charge
limits for A3 category refrigerants (including hydrocarbons)
by type of application:
• Household refrigerators: 2.01oz (57grams)
• Commercial refrigerators: 5.3oz (150grams)
• Room air conditioners: 2.2lb (1kg) of propane depending
on room size
Work on standards for hydrocarbons is ongoing and in
February 2011, the UL’s Joint Task Group on flammable
refrigerants established three working groups:
• Developing requirements for flammable refrigerants
for refrigeration equipment. The working group is
examining refrigeration equipment standards UL
563 (ice makers) and UL 621 (ice cream makers) for
possible inclusion of flammable refrigerant requirements;
• To address requirements for the testing and evaluation
of flammable refrigerants. The working group
discusses recommended updates to UL 2182 –
Safety Standard for Refrigerants.
UL is currently finalizing the certification criteria for
CO 2
transcritical systems, which will enable widespread
adoption of this technology in the North American
market. Until then, a special permission for the placing
on the market of such systems has to be received on a
case-by-case basis. In addition, UL listing can be granted
to specific products upon individual submissions. For
example, in December 2012, one USA-based company
announced that its CO 2
booster refrigeration system had
received UL listing in both the US and Canada 8 .
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• Developing requirements for flammable refrigerants
for air conditioning equipment. The working group
is looking at hydrocarbons for smaller, self-contained
equipment, while for larger applications, the UL is
working together with ASHRAE;
8 R744.com (2006), UL listing lifts final barrier to CO 2
transcritical use in
USA supermarkets, R744.com, 13 December 2012. Available from: http://
www.r744.com/news/view/3746 (Accessed: 10 January 2013)