Page 196 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

174 Cha pte r F o u r

To obtain this credit, the project must comply with either Option 1 or Option 2
relating to refrigeration and HVAC systems, and the project must also comply with the
requirement that the fire suppression systems do not contain ozone-depleting substances
(CFCs, HCFCs, or halons).
Option 1 and Option 2 only apply to systems or units that contain more than 0.5 lb
of refrigerant. Items such as standard household refrigerators and small water coolers
are excluded.

Option 1 Option 1, which relates to refrigeration and HVAC systems, is very simple. If
the facility uses no refrigerants except for those small units which are exempted, then
this option is fulfilled. In addition, if there are only natural refrigerants used for the
applicable systems (CO , NH , water, or propane), then this option is fulfilled. No
2 3
calculations are needed.
Option 2 Option 2 is more complex. It requires a series of calculations on the base
building HVAC systems using the following 10 variables:

GWP Global warming potential of refrigerant r (These are listed in Table 4.4.1 or
r
can be obtained from the EPA website. They typically range from 0 to
13,000 lb /lb .)
CO2 r
LCGWP The equivalent annual life-cycle-based global warming potential for system
i
i in lb /ton of gross ARI-rated cooling capacity of system i per year [lb /
CO2 CO2
(ton · yr)]
ac
LCODP The equivalent annual life-cycle-based ozone depleting potential for system
i
i in lb /ton of gross ARI-rated cooling capacity of system i per year
CFC11
[lb /(ton · yr)]
CFC11 ac
Life Equipment life of system i (The values as listed in the LEED-NC 2.2 and 2009
i
Reference Guides are listed in Table 4.4.2. Other values may be substituted if
appropriately documented by manufacturers’ data and warranties.)
Type of Equipment LEED 2009 Life (yr) * LEED 2.2 Life (yr) *
i i
Room or window air-conditioning 10 10
units and heat pumps
Unitary, split and packaged air- 15 15
conditioning units, and heat pumps
Reciprocating compressors and 20 20
reciprocating chillers
Scroll compressors 20 −
Centrifugal chillers 25 23
Screw or absorption chillers 23 23
Water-cooled packaged air 24 −
conditioners
All other HVAC&R equipment 15 15

∗ Or as updated from Abramson (see the ASHRAE Applications Handbook)

TABLE 4.4.2 Equipment Life as Given in LEED-NC 2.2 and 2009 Reference Guides