Radiant temperature has a greater influence than air temperature on how we lose or gain heat to the environment. Examples of radiant heat sources include: the sun; fire; electric fires; ovens; kiln walls; cookers; dryers; hot surfaces and machinery, molten metals etc. 3. Air velocity This describes the speed of air moving across the employee and may help cool them if the air is cooler than the environment. Air velocity is an important factor in thermal comfort for example: • still or stagnant air in indoor environments that
In cases where water is used as intermediate cooling medium, the overall effectiveness is composed of the charge air cooling effectiveness and the corresponding radiator effectiveness. In either case, since the ultimate heat sink is the ambient air, equation is the reasonable measure of the system effectiveness. The pressure loss
Consequentially, this helps in retaining heat. Through creating and maintaining such a balance, the body can carry out activities in either condition as the homeostatic system, and process controls the response of the body to the external factors that
(e) External shading devices are the most positive way of controlling solar heat gain. The effect of such devices on wind (thus ventilation) and on day-lighting and views must be kept in mind. (f) Insect screens (part of fenestration) may be a necessity in hot and humid climates (with their large insect population), but their effect on air flow and on day-lighting must be recognised. Air flow may be reduced by 30% even by the best, smooth nylon screen and
In this experiment the envionrmental gradient is temperature taken at a certain altitude and distance from the wall. The temperature is affected by the sunlight that the area or its surroundings are receiving. The surroundings is the distance from the wall of the building as well as the canopy cover. The temperature is also affected by other environmental factors such as the speed of the wind because that would cool the area down as well as how much of the area is shaded. Hypothesis: I predict that
The building envelope system consist of the elements of the outer shell that will form a dry, heated or cooled indoor environment. It acts as a strategy in achieving thermal comfort by providing thermal and weather barriers. It also provides an air barrier to prevent strong wind from entering. Not only does the system act as a strategy in providing structure and safety from fire, it also adds to the
(v) Avoiding radiation effects to cold surfaces. Interior surfaces of exterior walls and windows are usually colder than building’s occupants during winter. When this happens, people radiate heat to the colder surfaces. Therefore, they demand higher indoor air temperature to achieve thermal comfort levels. In order to avoid that and reduce heating load, people should sit away of the exterior walls and windows during winter.
According to Ron Kurtus, 2014, people use thermal insulation in because if the weather is cold they use jackets to keep them warm; the second is that houses uses thermal insulation to keep them from having high temperature inside; and the last is if a person wants to keep them hot, then they would a thermos that has thermal insulation. As seen from above, thermal insulation is important because of its uses to satisfy a man’s wants. According to Ron Kurtus, 2014, thermal insulators are used to prevent the conduction or transfer of heat. If a thermal insulator is good then this makes it a poor conductor of heat. According to Ron Kurtus, 2014, the materials that are poor conductors of electricity are also poor conductors of heat.
1. Introduction Thermal comfort is the condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation (ANSI/ASHREE Standard 55). There are six primary factors that directly affect thermal comfort that can be grouped in two categories namely personal factors and environmental factors. The personal factors are metabolic rate and clothing level, the environmental factors are air temperature, mean radiant temperature, air speed and humidity. The metabolic rate is decided by the human activity level and the heat loss from the body is decided by the clothing insulation value, the speed of body movement, openings in clothing and climatic conditions.
The thermal comfort of people depends on combinations of clothing, climate and physical activity. ISO 7330 defines thermal comfort as that form of mind, which expresses pleasure with the thermal surroundings. Majumdar et al  reported that thermal comfort properties of textile fabrics are essentially influenced by the fibre, yarn and fabric properties. In the comfort properties of fabrics, the type of fibre, spinning technology, yarn linear density, twist and hairiness of yarn, thickness, cover factor and porosity of fabric and finish are take part in vital role in determining the