Page 184 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

162 Cha pte r F o u r

Substituting this into Eq. (4.1.3) results in the following simplification based only on
regulated loads:
⎛ PDEMR REC ⎞ base process is 25% of base load
⎜
AECS = 75 1 − + ⎟
⎝
BBPR⎠ and does not change in design
(4.1.8)
BBPR
Equations (4.1.1) through (4.1.8) are for Option 1. A summary of the symbols as used for
calculating EAc1 Option 1 can be found in Table 4.1.4.

Symbol Description Comments
BBP Base building • Total includes both regulated and process loads.
performance ($) • Average of four model orientations.
BBPP Base building Default is BBPP = 25% of BBP
performance process
loads ($)
BBPR Base building
performance regulated
loads ($)
PDEM Proposed design Total includes both regulated and process loads.
energy model ($)
PDEMP Proposed design Process is same for base and proposed unless
energy model process specially addressed by the exceptional calculation
loads ($) method, but usually only regulated loads are
reduced.
PDEMR Proposed design
energy model regulated
loads ($)
REC On-site renewable Equivalent "savings" of off-site utility costs for using
energy cost on-site renewable energies.
"savings" ($)
PBP Proposed building Proposed design costs less rec savings:
performance ($) PBP = PDEM − REC
AECS Annual energy cost ⎛ PBP⎞
⎜
⎝
savings (%) AECS = 100 1 − BBP⎠ ⎟ or
⎛ PDEM REC⎞
AECS = 100 1 − BBP + BBP⎠ ⎟
⎜
⎝
ECM Exceptional calculation Method to calculate changes to the proposed design
method for some process load changes or some energy cost
savings for measures not readily included in the
energy model used.

TABLE 4.1.4 Summary of Symbols and Criteria Equations for EAc1 Option 1