MIL-HDBK-1133
Section 2:
ENERGY CONSUMPTION ESTIMATION
2.1
Data Collection. The initial estimate of energy
consumption (when no metered consumption data is available) is an
important first step in assigning total energy consumption to
individual buildings, ships, and other energy uses. This section
describes how to make those initial estimates for buildings and
ships. It also provides guidance for estimating other
nonbuilding energy uses such as those for street lights, water
and sewer systems, and produced energy such as electric
generation, processes, and distribution losses. For buildings,
the values include energy use intensities (EUIs) expressed in
kilowatt-hours per square foot per month (kWh/ft2/mo) or thousand
British thermal units per square foot per month (kBtu/ft2/mo)
(or, in SI units, thousand joules per square meter per month
[kJ/m2/mo]). The appropriate value for ship energy use is the
hourly use rate, expressed in kilowatt-hours (kWh) or thousand
British thermal units per hour (kBtu/h) (or, in SI units,
thousand joules per hour [kJ/h]).
A preliminary step in assessing energy use for an
entire installation or a few buildings is to collect basic
building and installation data. The following steps describe the
process of gathering this information.
NOTE
This process can be done manually or with any spreadsheet
or database software. Using a spreadsheet or database is
strongly recommended and will provide faster and easier
calculation.
a) All building energy assessments require three
related data items. These are the cooling degree-days ≥ 65
degrees F (18 degrees C) [CDD(65)], heating degree-days ≤ 65
degrees F (18 degrees C) [HDD(65)], and wet-bulb hours ≥ 73
degrees F (23 degrees C) [WBH(73)]. The values for these items
should be derived from actual current data wherever possible. If
current data is not available, a 30-year average (readily
available) can be used for annual estimates. These values should
be expressed in monthly or annual values, depending on the time
period of billing or use-estimation
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