UFC 4-826-10
10 July 2002
2-3
OPERATION AND MAINTENANCE. Tri-service facilities do not perform the
maintenance typical of commercial and industrial facilities. Participation of the site
operations and maintenance entities in the design process is critical to a safely operated
and maintained facility, plus helps to ensure a successful project. O&M entities will be
interviewed up front in the "Charrette" stage of a refrigeration design project. Design
charrettes are a key component in the initial stages of any project and should be
required. The mechanical designers (specifically the lead mechanical engineer)
involved in the refrigeration design should participate in the design charrette.
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ECONOMY. Design systems to provide the lowest life-cycle cost with maximum
energy efficiency and give special consideration to safety and low maintenance. As
noted in Section 2-3, the maintaining of Tri-services facilities is not indicative of
commercial and industrial facilities. Actual maintenance costs can be hidden and high.
Therefore, a simple, high reliability design can be weighed greater than efficiency.
Consider this in the life cycle analysis. Also, consider the impact of refrigerant phase-
out and replacement costs, and OSHA Regulations (refer to Section 2-6.3.2) to the life
cycle analysis of the refrigeration system.
2-5
REFRIGERANT PHASE-OUT AND REPLACEMENT. The phase-out schedule
of refrigerants is briefly defined in the refrigerants chapter of the ASHRAE Handbook
Fundamentals. This information can also be found at the United States Environmental
Protection Agency's web site http://www.epa.gov/spdpublc/title6/phaseout/.
Summarizing, the international treaty, Montreal Protocol, and its subsequent revisions
control the ozone depleting substances including refrigerants. This treaty dictated
complete cessation of the production of chlorofluorocarbons (CFC) in 1996 and halons
in 1994. The treaty also dictated the phase-out of hydrochlorofluorocarbons (HCFC),
including R-22, by reducing production of HCFC over the next 30 years, with production
reduced to 10% by 2015 of 1996 reference production level, and complete cessation of
HCFC production by 2030. HFC (including R-134a) are not regulated by the Montreal
Protocol. Below are some of the primary phased out refrigerants that have
replacements.
R-12 (CFC) has been phased out and the designated replacement is 134a
R-502 (contains CFC-115) has been phased out and the designated
replacement is R-404a
R-22 (HCFC) does not have a replacement at this writing and competes
with ammonia (R-717). But with a 90% production decrease by the year
2015, R-22 can become cost prohibitive during its phase-out, similar to R-
12.
2-6
SYSTEM DESIGN AND SELECTION. This section addresses the general
requirements for the design and selection of a refrigerated system for cold storage.
ASHRAE Standards are the basis for refrigeration system design, selection, installation,
testing, and operating. For ammonia systems, the standards of the International
Institute of Ammonia Refrigerators (IIAR) will apply, and if more stringent than ASHRAE
Standards, IIAR will prevail.
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