420 Energy Project Financing: Resources and Strategies for Success
ductivity, in part by reducing: a) costs for health care, b) sick leave, c)
performance decrements at work caused by illness or adverse health
symptoms; and d) costs of responding to occupant complaints and costs
of IEQ investigations. Some characteristics of the indoor environment,
such as temperatures and lighting quality, may also influence worker
performance without impacting health. In many businesses, such as of-
fice work^1 , worker salaries plus benefits dominate total costs; therefore,
very small percentage increases in productivity, even a fraction of one
percent, are often sufficient to justify expenditures for building improve-
ments that increase productivity.
At the present time, the linkages between specific building and
IEQ characteristics and productivity have not been well quantified.
However, in a critical review and analysis of existing scientific infor-
mation, Fisk and Rosenfeld (1997, 1998) have developed estimates of
the potential to improve productivity in the U.S. through changes in
indoor environments. The review indicates that building and HVAC
characteristics are associated with prevalences of acute respiratory infec-
tions and with allergy and asthma symptoms and non-specific health
symptoms. For the normal range of indoor lighting conditions, the
effects of improved lighting on the performance of typical office work
is poorly understood. Several studies have found performance to be af-
fected only by unusually low lighting levels or have found performance
to change only with small low contrast type (Fisk and Rosenfeld 1997).
However, a recent laboratory study with computerized performance
tests suggests that high frequency ballasts may increase performance
(Veitch and Newsham 1998). There is evidence that improvements in
lighting quality can improve the performance of work that is very visu-
ally demanding, such as mail sorting or detailed product inspections,
by several percent. Finally, there is evidence that quite small changes in
temperature, a couple of degrees centigrade, may increase or decrease
the performance of office work; however, the optimal temperature varies
with the type of work. Also, the optimal thermal conditions for work
performance may differ from the optimal conditions for comfort. From
analyses of existing scientific literature and calculations using statistical
data, the estimated potential annual nationwide benefits of improvements
in IEQ include the following:
- In office buildings, salaries are typically about 100 times larger than build-
ing energy or maintenance costs.