The following remarks were made regarding the article “HFO Sightings: Retrofits Becoming More Common in Supermarkets,” written by Joanna R. Turpin, senior editor for The NEWS, published Oct. 1.
ASHRAE ADDENDUM ADDRESSES RETROFITS
I enjoyed the article. Well done. There was one aspect that was not touched upon in the article, and perhaps could be included in a future article on the topic of refrigerant retrofits and not necessarily limited to supermarket applications. ASHRAE Standard 15 has for a very long time included requirements related to retrofitting an existing system with a new refrigerant, as well as the topic of mixing refrigerants. Many of those requirements date back to the 1990s when the industry started to replace CFC refrigerants. That standard is used in many building codes, either by transcription of requirements taken from ASHRAE 15 or by direct reference to ASHRAE 15 or some combination thereof. With the advent of a new generation of refrigerants, with lower global warming potential — but quite often also with the new hazard of flammability — the SSPC 15 committee that maintains ASHRAE Standard 15 recently developed a revision to the standard. It was published earlier this year as Addendum e to Standard 15-2016. The contents of that addendum will then be incorporated into the 2019 edition of the standard as part of ASHRAE’s routine continuous maintenance process. Building codes will then follow (and likely adopt) the same provisions. The language of the revisions is available for free at the ASHRAE standards web page. The full document for Standard 15 does require purchase.
A very brief summary of the changes is that they clarify what must be done to maintain safety when retrofitting a new refrigerant into an existing system. Of particular concern is retrofitting a flammable refrigerant into a system that was originally designed for a non-flammable refrigerant. From a technical point of view, it can be done for some systems. But in most cases, system design and component changes are required to maintain safety. From a financial point of view, the required safety changes have an impact on the economics of the decision to proceed with the retrofit.
Phillip A. Johnson
Applied Development Center
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Publication date: 11/12/2018