2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
526
A BIOMETEOROLOGICAL PROCEDURE TO DETERMINE THE
OPTIMAL OUTDOOR CLOTHING INSULATION FOR THE
FORECASTED WEATHER
Marco Morabito 1 , Alfonso Crisci 2 , Lorenzo Cecchi 1 , Pietro Amedeo Modesti 1,3 ,
Giampiero Maracchi 2 ,Gian Franco Gensini 1,3 , Simone Orlandini 1
1 Interdepartmental Centre of Bioclimatology - University of Florence, Florence, Italy
2 Institute of Biometeorology, National Research Council, Florence, Italy
3 Clinica Medica and Cardiologia, University of Florence, Italy
Contact person: marco.morabito@unifi.it
INTRODUCTION
The impact of climate change on human health and on general biological systems has been
widely described and most of the observational data series are consistent with the direction of
change expected as a response to warming. The rapidity of this climate change requires that
policymakers are kept informed of the manner in these changes can impact on human
adaptation and behavior, to ensure thermal comfort and avoid or reduce risks. For this reason
there is an increasing demand to assess the thermal climate in a human-biometeorologically
manner. Clothing represents an important variable directly involved in the estimation of
thermal load in relation to the physical activity and environmental parameters. Most studies
focused on the estimation of general thermal comfort of people for indoor thermal
environments and the Predict Mean Vote (PMV) (Fanger, 1972) represents the standard
method based on the steady state energy-balance model used by the International
Organization for Standardization (ISO 7730, 1994). On the other hand, relatively few studies
have investigated outdoor thermal comfort, because of the great complexity of the outdoor
environment. Recently we reported that the association of German engineers considered
stationary models, such as the PMV and similar thermal indices, useful to facilitate the
thermophysiological acquisition of thermal conditions even of surrounding outdoor air as
point layers. In several studies, thermal indices were employed, taking into account solar
radiation parameters, to improve the assessment of outdoor comfort, even creating bioclimatic
maps useful for urban planners, human health and helpful for saving energy. Dressing
properly for the outdoor environment is a component of thermoregulatory behavior, and it is
well known that ample outdoor clothing can contribute to the prevention of excess winter
mortality typical of populations living in temperate countries. The aim of the present work
was to investigate the clothing factor related to climate changes, retrospectively evaluating
the seasonal trend of the minimum clothing insulation value necessary to maintain the thermal
neutrality in outdoor spaces in three major Italian cities over the second half of the last
century. Subsequently an operational biometeorological procedure was developed to provide
72-hour forecast maps concerning the optimal outdoor minimum clothing insulation value to
maintain thermal neutrality over Tuscany and all of Italy.
METHODS
Preliminary analysis
Daily meteorological data of air temperature (°C), relative humidity (%), wind speed (m s -1 )
and cloud cover (in eighths) were measured at 04:00 (night), 10:00 (morning), 16:00
(afternoon) and 22:00 (evening) hours in three weather stations managed by the Italian
Meteorological Service for the period 1951-2000. These were located in three Italian
geographical areas: Northern Italy, Turin, λ = 11°11' E; Φ = 43°22' N; Central Italy, Rome, λ
= 12°58' E; Φ = 41°80' N; Southern Italy, Palermo, λ = 13°32' E; Φ = 38°12' N. In addition,
mean radiant temperature (Tmrt, °C), defined as the uniform surface temperature of an