Thermal Comfort Indexes

In Dubai, the absurd dependence on air-conditioning in buildings and vehicles has led to sedentary lifestyles and a poor public realm in many outdoor spaces. The microclimatic conditions that have been impaired by the morphology of the built environment, reduced pedestrian comfort between buildings. Urban spaces depreciate for many months due to lack of pedestrians. The present thesis aimed to encourage what it calls walkability – the ability of a place to welcome people to walk– for longer periods every year. It focused on improving pedestrians’ overall thermal comfort and extending the distances that they could travel along their daily utilitarian journeys.
Three main methods of fieldwork were applied to investigate the physical urban environment in two districts, namely Jumeirah Lakes Towers (JLT) and The Greens. First, interviews were conducted with random passers-by along their everyday routes to the mosque, metro, office and school. These were conducted at different periods of the year and times of the day and were meant to identify the thermal comfort limits at such periods. Second, subjective assessments, consisting of thermal sensations and thermal comfort votes, were collected from six subjects over several days in the form of short walks at different times of the year. These helped to assess the influence of the successive changes endured on the thermal sensations and overall comfort. Third, data loggers were installed in four different spaces over a period of one year to identify the influence of urban morphology on the microclimatic parameters (air and globe temperatures and relative humidity). Finally, ENVI-met microclimatic simulations were run to analyse the urban district JLT and identify the hot spots likely to inhibit comfort.
The findings of the fieldwork and simulation studies revealed the prospect for extending the distances that pedestrians tolerate walking outdoors, through improving their thermal sensation and comfort at certain areas along the journey described as the recovery conditions. The thesis proposes that allocating adequate shade and wind at frequent areas along the journey provides a psychological satisfaction and physical heat stress relief, which improves the overall comfort and encourages walkability. Proposed scenarios for such areas were modeled and tested using ENVI-met to show the improvements of the microclimate and comfort conditions that can be achieved at different times of the day and year.

Improving outdoor thermal comfort of the urban spaces is one of the most important challenges that cities have to carry out in the next years. The aim of this work consists of assessing the impact of urban variables and to quantify the influence of greening on outdoor thermal comfort conditions. The work compares six neighborhoods in the city of Turin characterized by different urban forms, contexts, and green areas. External thermal comfort conditions were measured by evaluating a series of indicators with the support of the ENVI-met tool. Through the analysis of various scenarios, outdoor thermal comfort conditions were measured using green mitigation measures, like vegetated areas, trees, and green roofs. The results allow the evaluation on how outdoor thermal comfort varies in relation to urban form and greenery. By comparing neighborhoods with different urban characteristics, it was possible to define the most effective form for the city of Turin. Higher levels of mean radiant temperature were obtained with open form neighborhoods with a prevalent East-West orientation, a low buildings' density, and a low height-to-width ratio. However, thermal comfort conditions can be mitigated by court-form districts and the presence of greenery, to increase the livability of the urban outdoor environment.

In Dubai, the absurd dependence on air-conditioning in buildings and vehicles has led to sedentary lifestyles and a poor public realm in many outdoor spaces. The microclimatic conditions that have been impaired by the morphology of the built environment, reduced pedestrian comfort between buildings. Urban spaces depreciate for many months due to lack of pedestrians. The present thesis aimed to encourage what it calls walkability – the ability of a place to welcome people to walk– for longer periods every year. It focused on improving pedestrians’ overall thermal comfort and extending the distances that they could travel along their daily utilitarian journeys. Three main methods of fieldwork were applied to investigate the physical urban environment in two districts, namely Jumeirah Lakes Towers (JLT) and The Greens. First, interviews were conducted with random passers-by along their everyday routes to the mosque, metro, office and school. These were conducted at different periods of...