Thermal Comfort, Productivity and Health One reason for

By admin on November 15th, 2007

Thermal Comfort, Productivity and Health

One reason for the low popularity of kitchen work is
the unsatisfactory thermal conditions.
Thermal comfort is a state where a person is satisfied
with the thermal conditions.
The International Organisation for Standardisation
(ISO) specifies such a concept as the predicted
percentage of dissatisfied occupants (PPD) and the
predicted mean vote (PMV) of occupants.
PMV represents a scale from -3 to 3, -from cold to hot -,
with 0 being neutral. PPD tells what percentage of
occupants are likely to be dissatisfied with the thermal
environment. These two concepts take into account four
factors affecting thermal comfort:
air temperature
radiation
air movement
humidity
The percentage of dissatisfied people remains under
10% in neutral conditions if the vertical temperature
difference between the head and the feet is less than
3 C and there are no other non-symmetrical
temperature factors in the space. A temperature
difference of 6-8 C increases the dissatisfied
percentage to 40-70%.
There are also important personal parameters
influencing the thermal comfort (typical values in
kitchen environment in parenthesis):
clothing (0.5 - 0.8 clo)
activity (1.6 - 2.0 met)
Clo expresses the unit of the thermal insulation of
clothing.