5.4.1 Applicability. This method defines acceptable thermal
environments only for occupant-controlled naturally conditioned
spaces that meet all of the following criteria:
a. There is no mechanical cooling system (e.g., refrigerated
air conditioning, radiant cooling, or desiccant cooling)
installed. No heating system is in operation.
b. Representative occupants have metabolic rates ranging
from 1.0 to 1.3 met.
c. Representative occupants are free to adapt their clothing
to the indoor and/or outdoor thermal conditions within a
range at least as wide as 0.5 to 1.0 clo.
d. The prevailing mean outdoor temperature is greater than
10°C (50°F) and less than 33.5°C (92.3°F).
5.4.2 Methodology. The allowable indoor operative temperatures
(to) shall be determined from Figure 5.4.2 using the
80% acceptability limits or the equations in Section 5.4.2.2.
Note: The 90% acceptability limits are included for
information only (see Informative Appendix I for further
guidance).
5.4.2.1 The prevailing mean