190 Energy Project Financing: Resources and Strategies for Success
least one to two year’s worth of energy bills. This information should
be put into a table and also plotted.
Conducting the Audit
A signifi cant difference in industrial and commercial audits arises in
the area of lighting. Lighting in commercial facilities is one of the largest
energy costs—sometimes accounting for half or more of the entire electric
bill. Lighting levels and lighting quality are extremely important to many
commercial operations. Retail sales operations, in particular, want light
levels that are far in excess of standard offi ce values. Quality of light in
terms of color is also a big concern in retail sales, so fi nding acceptable
ECOs for reducing lighting costs is much more diffi cult for retail facilities
than for offi ce buildings. The challenge is to fi nd new lighting technologies
that allow high light levels and warm color while reducing the wattage
required. New T8 and T10 fl uorescent lamps, as well as metal halide lamp
replacements for mercury vapor lamps, offer these features and usually
represent cost-effective ECOs for retail sales and other facilities.
RESIDENTIAL AUDITS
Audits for large, multi-story apartment buildings can be very simi-
lar to commercial audits. (See section 3.6.) Audits of single-family resi-
dences, however, are generally fairly simple. For single-family structures,
the energy audit focuses on the thermal envelope and the appliances,
such as the heater, air conditioner, water heater, and “plug loads.”
The residential auditor should start by obtaining past energy bills
and analyzing them to determine any patterns or anomalies. During the
audit visit, the structure is examined to determine the levels of insula-
tion, the presence and condition of seals for windows and doors, and
the integrity of the ducts. The space heater and/or air conditioner is
inspected, along with the water heater. Equipment model numbers, age,
size, and effi ciencies are recorded. The post-audit analysis then evalu-
ates potential ECOs, such as adding insulation, double-pane windows,
and window shading or insulated doors. Changing to higher effi ciency
heaters, air conditioners, and water heaters is also considered. The audi-
tor calculates costs, benefi ts, and simple payback periods and presents
them to the owner or occupant. A simple audit report, often in the form
of a computer printout, is given to the owner or occupant.