Measuring the Savings from Energy Control Window Film Installation Using IPMVP Options C and D

Abstract

Building owners and property managers have provided numerous
reports of the energy savings obtained from the retrofit installation of
energy control window film to existing buildings. In many cases, sub-
stantial energy savings are reported with simple paybacks often within
one to four years. However, such claims have not been produced using
the rigorous methods prescribed by the International Performance Mea-
surement and Verification Protocol (IPMVP, see www.ipmvp.org).
To provide for more definitive evidence of the savings from the use
of energy control window films, CPFilms undertook a demonstration
project to install window film on a mid-size commercial office building
and then measure the resulting energy savings using two separate
IPMVP methods. The measurement of savings involved the use of
IPMVP Option C (whole-building method using utility bill analysis) and
Option D (calibrated simulation). During the twelve months following
film installation, Option C measured savings of 8.8 percent were
achieved, which includes savings over both the cooling and heating
seasons. This compares favorably to Option D, calculated savings of 8.4
percent that were estimated prior to film installation.