Role of daylight in local hospitals design

Environmental sustainability is one of the most important, and one of the sustainability criteria is Daylight that trying to provide it in hospital spaces and which improve the patients status(healing of patients), by looking at studies concerned with the role of Daylight in the design of local hospitals, we find a knowledge gap emerged regarding the lack of studies that dealt with the design of Daylight in local hospitals and its effect on the healing of patients (a special problem for the research). The goal of the research is to determine the role of Daylight in hospital design. Research hypothesis: the Daylight affect the healing of patients at local hospitals by achieving comfortable zone at patient room and this affected by the orientation of these rooms and relationships between the location of head of patient and the TV wall at these rooms, in the practical side we select two hospitals and prepare the sites measurements by using LUX meter instrument, In this aspect, the intensity of the light and the indicators associated with it were measured, as a group of patients rooms were elected on multiple facades of the hospital building, as these rooms were numbered and their location in the plans based on the numbering system in the hospitals and then the details of the room were determined dimensions, the window’s location and its relationship with the bed, the location of the patient’s head in the room and the location of the TV wall (the front facing the patient’s head), as a mock net was drawn 95 cm from the ground level and the net was 50 cm away from the walls and the distance between One point and another is approximately 85 cm in both directions, and a mock square grid (2 meters * 2 meters) was drawn on the wall opposite the patient’s head (the TV wall) and the distance between one point and another is 50 cm. If the hospitals’ engineering plans were obtained, then the rooms for the patients’ rest were elected in the wards, provided that every two rooms were facing each other in the same wing after the sun’s movement was determined. The direction of those rooms was determined. The research reached a number of conclusions on designing natural lighting in local hospitals and determining within measures specific to the Iraqi environment. The most important conclusions of the eastern and southern directive were the orientation of the eastern and southern patient rooms to better rooms for patients, which in turn helps to heal patients.


Introduction
Hospitals are considered one of the most complex institutions due to the work natures and the privacy of dealing between their components, which need accuracy in achieving their functional and mobility requirements. They are also one of the institutions that must be operational and effective in different circumstances and have the first role player in rescue when natural disasters pandemics and Risks.
Daylight's importance in hospitals is that it has become a global trend to rely on natural resources instead of finding alternatives that have negatively affected the planet due to their byproducts such as carbon dioxide and natural resources as fossil fuels other materials. Also, Daylight has a positive impact on inpatients psychological side, as studies have shown that patients exposed to Daylight are characterised by good health, shorter stay time and less pain. Locally, attention to using Daylight in hospital design is still little. We find a knowledge gap regarding Daylight studies in local hospitals and its effect on patients' healing (a special problem for the research). The research goal was identified: For adequate Daylight in achieving a locally sustainable hospital building).and the objective of the research was to determine the appropriate daylight design indicators for the local, sustainable hospital. Daylight exposure decreases stress among patients. Suffering from "The "bipolar illness" successful seasonal condition decreases stay in the hospital, improves circadian rhythms, decreases patient excitement and apprehension, relieves discomfort, and improves employee adaptation to work at night). Since patients have shorter stay times in east-facing rooms than patients in west-facing rooms, in the morning, exposure to bright light is more effective at minimising depression than at night. (Less stress, less pain, 22% less pain medication, 21% fewer drug costs). [1]. Daylight's effect in intensive care rooms was also found to affect myocardial infarction patients treated in either sunny or windowless rooms. [2] The capacity of nurses is another consideration with regard to lighting in hospitals. [3] Figure 1.

The role of Daylight in hospitals
As studies have shown, patients have shown that patients exposed to Daylight are characterised by good health, shorter stay time, and less pain. Locally, attention to using Daylight in hospital design is still little. We find a knowledge gap regarding Daylight studies in local hospitals and its effect on patients' healing (a special problem for the research). The research goal was identified: For adequate Daylight in achieving a locally sustainable hospital building).and the objective of the research was to determine the appropriate daylight design indicators for the local, sustainable hospital.
Several factors affect the physiological nature of individuals from the point of view of ecological architecture. Human health and comfort in the environmental design are major concerns. "Comfort" is, however, a fundamental necessity for human wellbeing. "Feeling contented" is an optimistic concept of comfort. This concept is based on environmental factors. Thermal condition, Humidity, consistency of indoor air, visual ease and acoustic comfort. [4] Nowadays, by taking advantage of external environmental variables, engineers can improve patient rooms' internal outmosfer. As a result, the indoor room is well-adapted for physical and psychological comfort to meet the patients' environmental requirements. Both environmental factors in healthcare facilities may also benefit patient outcomes if they can design it properly.

Concepts of the role of Daylight in the indoor environment
The perception of light is influenced by several principles, which can be explained as follows: First, the light intensity is an essential factor that must be taken into account; It is the cumulative amount of light on a given surface. Lux is a measuring unit. The light intensity changes during the day and even between the seasons due to the sun's shifting positions and the differences include visibility in.the.sky [5].
The degree of lighting and its distribution throughout spaces reflect this transition, and this occurs with the difference in illumination adjacent window and the back of .room, [5].The light concept period varies according to the season and the sky's state [6]. Daylight's duration on a winter day is shorter than in summer. Also, there were differences in lighter ,the blue light was significantly less on winter days, while red and green light was higher in winter days. [7].
The colour of the illumination depends on the wavelength of the light. Colour vision is caused by separate wavelengths [8]. During the day, the daylight colour varies, morning, you can find a blue spectrum and red spectrum afternoon till evening [9]. the colour wavelengths are shown in Table no1, Hormones like cortisol and melatonin are secreted associated with light colours [10]. The blue spectrum causes a spike in cortisol, so the cortisol level is at its peak between morning and afternoon. Cortisol raises the energy level of an individual, which contributes to the ability to perform long-term tasks. The melatonin level interacts with the red spectrum, leading to an evening rise in melatonin. The sleep hormone is also referred to as melatonin, and the rhythm of sleep and waking up is regulated by one of its functions. It can be concluded from this that Daylight causes an increase in energy levels during the day and that Daylight causes an increase in melatonin levels. Serotonin is the third hormone that is affected by illumination. [11] In their research, sunlight may affect serotonin development directly through the skin. Serotonin is classified as a pain suppressant hormone. [12]  Under skin reduce the feeling of pain daylight Light VitaminD 4 4. International applied practices Emphasis will be placed on applications of some international hospitals in the field of Daylight to building a comprehensive theoretical framework for Daylight in hospitals, within their indoor spaces as follows:

Mediplex Sejong Hospital, Incheon, South Korea
The hospital build on 1996 (18 floors) in Incheon Korea. The climate in the city is continental and seasonal.its consisted of the southeast and northwest facing a single T-shaped building. There were similar and identical spaces, finishes, furnishings and equipment for all patient rooms. The data (direction of each patient's room and the position of the patient's heads relative to the window) were categorised according to the data-every wing in the hospital of choice, Figure 2. At the site, a set of points were determined for measurement. As measurements were made on-site for each selected room according to the previously mentioned points, The reflection of the inner room's surface was measured, and the glass was tested. At the height of 0.95 meters from the ground in the study, four reference points were selected. The levels of patient rooms and lighting were assessed.  There were some cases, on the other hand, which were higher than the allowed rates. The brightness ratio revealed moments of 90: 1 on the TV wall, In the Form A room facing the SE, or greater, particularly in the mornings in the spring (compared to other seasons). However, if this high luminance ratio needs to be avoided by the patient, the blinds may well be closed to reduce the high 8.6:1 maximum incidence, which is smaller than the prescribed ratio. Naturally, the SE room had a higher capacity for LR luminance than the NW room in the morning and In the afternoon and vice versa.

Diversity of illuminance (DI).
Lighting diversity patterns were similar in every direction since they are closely correlated with illumination levels. The light diversity values are usually higher than the Chartered Institute of Construction Services Engineers (CIBSE). Research Conclusions: a. There is a clear relationship between the patient's stay time and the natural light environment. b. By installing suitable shading devices, the discomfort caused by excessive daylight glare can be resolved. The high luminance ratio, brightness diversity, and brightness level can be managed and modified according to the values recommended by CIBSE and IESNA. c. Patient-controlled shading has a positive impact on the comfort of patients and enhances patient satisfaction. d. It may be conducive to rapid recovery to recognise disease types and the physiological benefits offered by Daylight. e. High lighting was more beneficial in the morning than it was in the afternoon. For patient rooms that are southeast-northwest-oriented, for more details and to reach practical indicators for Daylight's role inpatient rooms, international hospitals have been addressed, which have adopted the strategy of Daylight, as shown below.

ST. JOSEPH REGIONAL HEALTH CENTER Texas, USA
Hospital build in Texas.This hospital is divided into Building A and B sections due to each building's different daylight conditions. Half of the patient rooms face south and half face north, respectively.   First: lighting variables. The patient rooms' internal environment components were calculated (daylight factor, brightness ratio, average brightness, diversity of lighting, uniformity of illumination).Conclusions of the study: • Exposing them to Daylight in the morning reduces the length of stay in the hospital to a lesser period than rooms that are not exposed to the morning sun.

Indicators for designing Daylight in hospitals.
o Previous international studies have shown that there is a strong relationship between daylight design and patient recovery. This fact has been proven through statistics in hospitals with linking the length of stay of patients to the rooms in which they were the location of those rooms in the building and the room's relationship to the sun. o In this research, the indicators related to Daylight inpatient rooms will be analysed and the appropriate measures for the local Iraqi conditions and international standards. Where the internal daylight indicators consist of the following words: (daylight factor DF, IR ratio, level of light intensity, lighting diversity, lighting uniformity) which will be measured according to the following: 5.1. Daylight factor DF It represents the optical ratio necessary for Daylight DF = Indoor Luminance / External Luminance,(Keith Robertson M. Arch (1999) p:4). The values of 1.0% were determined for the daylight factor values as appropriate levels for the interior lighting of patient rooms, depending on the design values of the sky of Baghdad. According to this value for the daylight factor, the weights were placed in five levels according to this factor's achievement in the design, with an efficiency ranging (20% To 100%) Figure 7.

Luminance Ratio LR
A. The speed of adaptation and response of the eye, and avoiding .the inconvenience, .of. Changes in lighting levels, the difference between the average luminance of the visual field / the rest of the field of view should have fewer differences. The recommended value does not exceed 1:40. Figure 8 shows the levels of lighting values achieved within the space for visual comfort. B. The discrepancy in the luminance ratios between the TV and the human eye does not exceed 1-10.

Luminous Intensity (Lux)
Lighting and its distribution in and around the mission area have a significant impact on a person's pace, protection and comfort in perceiving the conditions and taking account of the following reasons: There are several different guidelines for activities according to the styles of building and room files for psychological and physiological aspects. The ideal recommended value is 100 lux (Figure 10).

Variety of Luminance (VI)
The luminous diversity index levels are expressed in terms of the highest illumination ratio to the lowest of it at any point in the working plane of the main area of the space or room 5: 1, Figure 11.

Illumination Uniformity (IU)
The standardisation of illumination deals with the patient's lighting conditions and the immediate environment. It does not extend to the entire room level, but the working level's lighting must be homogeneous. rate of not less than 80%  Figure 11: Weights of uniformity of illumination in the patient room [Researcher] After determining the theoretical framework's vocabulary and developing indicators for its measurement, it will be applied in the following paragraph to a sample of local hospitals to measure their design efficiency for natural lighting.

Local Practical application:
Hospitals have been elected that have a clear impact on the Iraqi community, as they are visited by the governorate and people of other governorates due to the presence of distinguished consulting services and staff to the multiple activities they provide. Accordingly, the following local hospitals were elected: 1  The practical application was carried out on 9/9/2020, when the sky was clear and the average intensity of the external lighting was 93,000 lux, with direct light and 1420 lux in the shade. It took interior and exterior lighting measurements between the hours (11 am-2 pm). The measurements for indoor lighting we fallowing the practical aspect as shown. The intensity of the light and the indicators associated with it were measured, as a group of patients rooms were elected in multiple facades of the hospital building, as these rooms were numbered and located in the plans based on the numbering system in the hospitals, and then details were determined and drawn. The room and highlighting the dimensions of the room, the location of the window and its relationship with the bed, the location of the patient's head in the room and the location of the TV wall (the facade opposite the patient's head), as an imaginary network was drawn 95 cm from the ground level and the network is 50 cm away from the walls and the distance Between one point and another, approximately 85 cm in both directions.
Other an imaginary network was drawn on TVwall (2 meters * 2 meters) opposite the patient's head, and the distance between one point to another was 50 cm, and readings of all intersection points in the network were taken using a lux meter device After the engineering plans of the hospitals were obtained, the rooms for the patients' rest were elected in the wards, provided that all two rooms were facing each other in the same wing after the sun's movement and the direction of those rooms were determined.   To reach a uniform illumination ratio for the entire hospital, and from the ratios that he reached, the luminance ratio was LR = 1: 2.9, concerning the luminance ratio indicator in paragraph (2-5 a), the achieved ratio: 100% B-2 the illumination ratios between the TV wall and the human eye do not exceed 1-10 The brightness was taken on the wall opposite the patient's bed. The ratio was calculated between the wall's average illumination intensity opposite the patient's bed (TV wall) with the luminance intensity at the patient's head, Table (4).  The average light diversity values were 5.2: 1, and concerning , which indicated that the average intensity ratio of highest / lowest light intensity for all rooms does not exceed = 1: 5, so the ratio achieved: 0%. 6.1.5. Illumination uniformity (IU). It is required that the average light distribution of the work level be homogeneous, not less than 80% and Table No. (7) Shows the values of measuring the lighting levels inpatient rooms.
All patient rooms are homogeneous in terms of intensity of illumination near the patient's head, uniformity of illumination ratio = 1: 1 concerning paragraph , the achieved ratio: 100% The values of the practical measurements and the results were as shown in Table 9.