عنوان مقاله [English]
Due to the nature of their functions associated with physical and spiritual health of the human beings and the complexity of these functions, considering the appropriate design requirements is vital in the design of hospitals and healthcare centers. One of these requirements is the correct usage of daylight. So far, many experimental studies have been performed on the beneficial effects of daylight on patients’ health (Ulrich, 2004). By relying on experiences of the experimental and field studies, this article describes the physical and psychological effects of daylight on patients. Then, by using the outcomes of previous researches and surveys in association with the characteristics of proper daylight, considering the specific climatic conditions in each region and the existing valid standards of daylight, an appropriate physical solution is recommended in temperate and humid climates for optimum usage of daylight in hospital bedrooms (Orbit 36 to 38 degrees). Designing appropriate windows for mild-humid climate (orbit 36 to 38 degrees): The main factors in creating healing environments with regard to daylight consist of: sufficient amount of daylight, appropriate shape of windows and control of the unwanted direct sunlight (CABE, 2004). The adequacy of daylight in a room is measured by average daylight (DF). DF should be at least 2 percent, although 3 percent of DF is recommended for most hospital spaces. However, the areas with a DF of more than 5 percent will encounter the problem of discomfort glare (CIBSE, 1999). The average daylight for inpatient hospital rooms can be calculated using the following formula: Equation (1): computing the daylight (CIBSE, 1999)
In the specific climate of temperate and humid, studied in this paper, considering DF= 3 percent and substituting the other factors in equation (1) in accordance with the standards of the Management and Planning Organization of Iran (3 = (w*0.90*0.5)/(1-0.25)*84.9), the size of window for a two-bed hospital room is calculated to be 4 square meters. The shape and dimensions of canopies (to avoid the access of direct sunlight to the inside of bedrooms) in so-called climate in this paper is obtained and equals to 1.10 m. Modeling bedroom in lighting simulation program (Dialux):
To check the accuracy of the computed size of windows in two-bed hospital rooms in temperate-humid climates studied in this paper, the windows in rooms with the direction of latitude and longitude of 36° and 52°, while rotating 15 degrees from the North axis (Appropriate angle for this climate) is modeled in Dialux software. The output of simulation is interpreted through the intensity of luminance or Lux (lx). To be able to turn it into DF, the Emin/Emax is multiplied by 101. For the case of this paper 101*0.036 is equal to 3.6 which means the DF is 3.6%, that is in the range of standards of average daylight (2%-5%). While, there is not much difference with the calculated DF by equation (1) which was 3%. The main critical point about the standard designing system of hospital bed rooms in Iran is the unequal exposure of beds to daylight, with beds closer to the window getting more light than those which are farther from it. In this paper, another arrangement of hospital bedrooms is presented by applying the main standard, as a solution for this problem. Moreover, the standards indicate that the maximum window sizes in temperate and humid climates must be 30% of the windows wall, but in the results of modeling, minimum size is 38% (the ratio of windows area to windows wall is 4/10.8).