78 / 188
BEAM P
LUS FOR
E
XISTING
B
UILDINGS
M
ATERIALS
A
SPECTS
(M
A
)
V
ERSION
1.2
M
A
6 O
ZONE
D
EPLETING
S
UBSTANCES
Copyright © 2012 BEAM Society Limited. All rights reserved.
Page 60
refrigerants are ideal. Compounds that contain no chlorine or bromine
have ozone depletion potential (ODP) nearly zero. Increasing the amount
of fluorine generally raises the global warming potential (GWP).
Hydrogen content tends to shorten the atmospheric lifetime [4].
Climate change is much more complex than ozone depletion, yet there is
wide agreement that warming is occurring. While refrigerants contribute
to global environmental concerns, the impact is comparatively small [4].
The problem is not with refrigerants inside air-conditioning systems, but
with their release. Given that ODP is largely addressed by legislation,
BEAM basis assessment of refrigerants is based on GWP.
CFCs generally have high ODP and GWP. HCFCs generally have much
lower ODP and GWP. HFCs offer near-zero ODP, but some have
comparatively high GWPs.
Refrigerant
ODP
[1]
GWP
[1]
Hydrofluorocarbons
HFC-23
~0
12240
HFC-32
~0
650
HFC-134a
~0
1320
HFC-152a
~0
140
HFC-402A
~0
1680
HFC-404A
~0
3900
HFC-407C
~0
1700
HFC-410A
~0
1890
HFC-413A
~0
1774
HFC-507A
~0
3900
Hydrochlorofluorocarbons
HCFC-22
0.04
1780
HCFC-123
0.02
76
Chlorofluorocarbons
CFC-11
1.0
4680
CFC-12
1.0
10720
CFC-114
0.94
9800
CFC-500
0.605
7900
CFC-502
0.221
4600
[1] – Sources:
i: IPCC Second Assessment Report;
ii: “World Resources Institute (2005), World Business Council for
Sustainable Development”;
iii: US Environmental Protection Agency.
The U.S. Environmental Protection Agency provides information on
suitable substitutes for ozone depleting substances [ 5 ], including
refrigerants for various types of air-conditioning and refrigeration
equipment, fire suppression [6], blowing agents [7], solvents, etc. CIBSE
GN01 [ 8 ] outlines the hazards of the use of these refrigerants and
provides design guidance for refrigeration systems, thermal insulation
4
Calm S M. Option and outlook for chiller refrigerants. International Journal of Refrigeration. Vol. 25, 2002, pp 705-715.
5
U.S. Environmental Protection Agency
. http://www.epa.gov/docs/ozone/snap/lists/index.html#refac6
U.S. Environmental Protection Agency.
http://www.epa.gov/ozone/snap/fire/index.html7
U.S. Environmental Protection Agency
. http://www.epa.gov/docs/ozone/snap/foams/lists/index.html8
Chartered Institution of Building Services Engineers. CFC’s, HCFC’s, HFC’s and halons. 2000. ISBN 0900953993.