444 Energy Project Financing: Resources and Strategies for Success
ally, surveys can only assess the responses to IEQ that are sensed by the
human sensory systems. IEQ exposures that increase the risk of some
chronic health effects, such as lung cancer from radon exposures, will
not be detected using surveys.
The survey design and methods of administration can affect the
outcome; therefore, surveys should be based on established question-
naires and on survey administration methods developed by staff with
suitable expertise. High response rates (e.g., > 80%) to surveys are nec-
essary to reduce risk of bias (e.g., a higher response rate from unhappy
occupants could bias the overall results).
Well-established survey methods are available for thermal comfort.
Thermal sensation is commonly assessed using a seven-point scale (e.g.,
ASHRAE 1992b, ISO 1994). Baseline data are being compiled by de Dear
and Brager (1998) from thermal comfort surveys performed throughout
the world.
Several survey instruments (questionnaires) have included broad
assessments of the level of satisfaction with, or perception of, multiple
IEQ parameters such as lighting level, lighting quality, acoustical quality,
air movement, acceptability of indoor air quality, ventilation, etc. These
same surveys have generally collected data on the prevalence or severity
of non-specific health symptoms experienced by office workers.
A U.S. EPA-supported survey is collecting data on non-specific
symptoms from 100 office buildings in the US (EPA 1994; Brightman et
al. 1997). A European Audit Project has collected symptom data from 56
office buildings (Bluyssen et al. 1996). Stenberg et al. (1993) and Sundell
(1994) describe similar data obtained from approximately 5000 office
workers in 210 buildings in Sweden.
Questionnaires to evaluate occupant satisfaction with lighting are
available (Collins et al. 1990, Dillon and Vischer 1987, Eklund and Boyce
1995, Hygge and Lofberg 1998) although customization for specific ap-
plications may be required.
8.6 M&V ALTERNATIVES FOR SPECIFIC I EQ PARAMETERS
In tabular form, this section identifies M&V alternatives for specific
IEQ parameters and provides comments on these alternatives. The M&V
alternatives for thermal comfort and ventilation are listed first because
energy conservation retrofits more often affect these IEA parameters.
The tables do not include all possible M&V alternatives. The alternatives
judged to be the most practical and valuable are marked with “♦.” Gen-