Simulations under current TMY

The benchmarks, recommended from literature (190 lx to 2000 lx) to ensure therapeutic effect of daylight effectively, were universal based on human biological system, and once confirmed with the data collected from Dhaka, Bangladesh, that was objective in nature; the suitability of using the benchmark to other geographical locations were justified. The benchmarks were used to evaluate the therapeutic potentiality of an imaginary in-patient room located in central London by prospective simulation study. The principles of trial-and-error method were followed in the parametric simulation analysis to support a decision. The eight steps shown in Figure 3.9 were followed to develop and compare therapeutic daylit space to support hospital patients‟ recovery.

68 SKY WINDOW 800 750 1200 600 1200 Blocked View 1200 825 450 1200 ADB (2009) Model HBN 04-01 (2008) DH (2005) ECOTECT (2010) Model

DAYSIM (version 2.1) Analysis

Comparison of Dynamic Performance Metrics

(h) Parametric simulation study to compare performance measures for different design variants (g) The goal for DA and UDI>2000 for London

(f) Selections of simulation tools for measuring performances.

(e) Identification of the performance target and measures criteria for evaluating therapeutic potentiality of the 3D spaces.

(d) Development of a therapeutic daylight design concept for the 3D example space (c) Fixing the test points for daylight measurement in 3D space

(b) Development of a 3-dimensional example space based on best practices in UK (a) Studying the microclimate of the geographical location (London) of the hospital building for

simulation analysis. 825 1200 825 1200 825 775 1200 1200

69

a. Microclimate of the geographical location (London)

The potentiality of achieving any daylighting goal primarily depends on the geographical location of the building site. The coordinates of Central London are 51°30′29′′N and 00°07′29′′W. London uses Greenwich Mean Time (GMT) + 0, for less than half of the year. During summer time (daylight saving time), London uses GMT+1, also known as British Summer Time (BST). London has a temperate marine climate (Koppen climate classification), similar to much of the British Isles. Extremely high or low temperatures are rare in London. The city has mainly four distinct seasons: summer, winter, spring and autumn. Summers are warm with 11°C – 20°C average temperatures. Winters are chilly with daytime highs around 4°C – 10°C, but rarely below freezing. Spring has mild days and cool evenings. Autumn is usually mild but often unsettled as colder air from the north and warmer air from the south meet (CIBSE Guide J, 2002).

The weather of London is mostly dry with regular but generally night precipitation throughout the year, with an average of 583.6mm every year. Snows are relatively uncommon, particularly because, heat from the urban area can make London up to 5 °C warmer than the surrounding areas in winter. Table 3.4 shows the monthly average climatic condition of London.

Table 3.4: Average climatic conditions of London, UK (BBC, 2006).

Month Average sunlight (hours) Temperature Relative humidity Average precipitation (mm) Wet days (+0.25 mm) Average Record

Min Max Min Max AM PM

Jan 1 2 6 -10 14 86 77 54 15 Feb 2 2 7 -9 16 85 72 40 13 Mar 4 3 10 -8 21 81 64 37 11 Apr 5 6 13 -2 26 71 56 37 12 May 6 8 17 -1 30 70 57 46 12 Jun 7 12 20 5 33 70 58 45 11 Jul 6 14 22 7 34 71 59 57 12 Aug 6 13 21 6 38 76 62 59 11 Sep 5 11 19 3 30 80 65 49 13 Oct 3 8 14 -4 26 85 70 57 13 Nov 2 5 10 -5 19 85 78 64 15 Dec 1 4 7 -7 15 87 81 48 15

70 London has an average 4 hours of sunshine a day and the sky is predominantly overcast (Figure 3.10) all over the year (Schepers et al., 2009). The CIE defined standard overcast sky as, steep luminance gradation towards zenith and azimuthal uniformity (CIE, 2004). Figure 3.11 shows the sun path diagram of London. London sun angle exists below 450 for 90% of the year with a highest solar altitude of 620. The daylight hours for London vary from 8 hours (during December) to 16.5 hours (during June) throughout the year. Analysing the sunrise - sunset data of London, it was found that the earliest sunrise time was recorded at 04:43 AM and late sunset time at 09:22 PM on June 21 with a daylight hour of 16 hour 39 minutes. The late sunrise time recorded at 08:04 AM and earliest sunsets at 03:54 PM on December 21 with a daylight hour of 7 hour 50 minutes (WCI, 2010b). Though the data is for 2010, the sunrise and sunset times can be applied for any year (LW, 2009). Figure 3.12 shows the hourly solar radiation averaged by month for TMYs, London and Figure 3.13 presents the calculated hourly HEI of the 21st of each month for TMYs, London. Based on ECOTECT Weather File, 2010, the highest HEI was 72,596 lx on June 21 at 12:5 PM and lowest HEI at 12:5 PM was 6,313 lx on November 21. Considering the daylight situations, it can be concluded that it will be difficult to achieve sufficient daylight for therapeutic purpose for a typical hospital building located in London.

100% 80% 60% 40% 20% 0%

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Figure 3.10: Cloud cover for TMYs, London (source of data: ECOTECT weather file, 2010).

71

Figure 3.11 :The sun path diagram of London, UK (source: SUNTOOL - Solar Position Calculator, 1998).

Direct Solar Diffuse Solar

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.00k 0.05k 0.10k 0.15k 0.20k 0.25k S o la r ra d ia ti o n ( W /m ²) 0.30k 0.35k

Figure 3.12: Hourly solar radiation averaged by month for TMYs, London (source of data: ECOTECT weather file, 2010).

72 0 10000 20000 30000 40000 50000 60000 70000 80000

21 Jan 21 Feb 21 Mar 21 Apr 21 May 21 Jun 21 Jul 21 Aug 21 Sep 21 Oct 21 Nov 21 Dec

Il lu m in a ti o n ( lu x )

Figure 3.13: Calculated hourly HEI of the 21st of each month for TMYs, London, based on ECOTECT weather file, 2010.

b. 3-dimensional example space

Historically, in-patient accommodations have been the central part of hospital buildings and still occupying the significant proportion of space in a hospital (HBN 04-01, 2008). To ensure therapeutic benefit of daylight for hospital patients, it is sensible to ensure sufficient daylight inside in-patient rooms where the patients are largely stationary. Ne‟eman (1974) also emphasise the necessities of daylight, for health purpose, inside in-patient rooms in healthcare facilities, as patients have low mobility compared to staff and others who have options to leave the premises and enjoy daylight more easily. Nowadays, patients are more concerned and have higher expectations of the quality of the space where they are getting treatment. In this regard, the option of single-bed room with provision of high-quality indoor facilities is likely to be the influencing factor in creation of patient-led NHS in near future (HBN 04-01, 2008; DH, 2005a). The majority of patients prefer single-bed rooms due to improved quality of sleep, greater privacy, opportunity for family members to stay, reduced noise, reduced embarrassment, and avoidance of upsetting other patients (Douglas et al., 2002; Kirk, 2002; Pease et al., 2002; Reid et al., 1973).

The current trend in hospital design is to promote patient-centred care and family participation in the patient curative process, where the patients are treated in universal rooms or acuity adaptable rooms consists of private rooms only (AIA, 2006). Studies showed that patient falls, medication errors and procedural problems can be reduced in acuity adaptable rooms (Hill-Rom, 2002; Gallant et al., 2001; Bobrow et al., 2000; Spear, 1997). In the publication titled, „Guidelines for Design and Construction of Hospital and Health Care Facilities (issue: Single versus multiple bedroom occupancy)‟, AIA (2006) addressed several key issues on the advantages of single-bed

73 rooms on reduction in the risk of cross infection, improvements in patient care, and greater flexibility in operation. Operating costs are less in single-bed rooms due to higher bed occupancy rates, reduction in transfer cost, and reduction in labour cost with comparison to multi-bed rooms (Hill-Rom, 2002; Ulrich, 2003). Single-bed rooms increase patients‟ control over personal environment with opportunities to discuss their needs with friends and family (Bobrow et al., 1994; Burden, 1998; Morgan et al., 1999), and more private and thorough consultation with healthcare stuff (Ulrich, 2003). Considering the advantages and acceptances of single-bed in-patient unit to patients, an example module of high quality single-bed in-patient room was developed as case space for the simulation exercise in this research.

The 3D in-patient single-bed room used in the simulation exercise was developed according to the guideline described in Health Building Note 04-01 (2008), published by the Department of Health (DH), UK. HBN 04-01 is a planning and design guideline for adult in-patient facilities. It describes bed, patient support spaces, stores, utilities, sanitary facilities, administration areas and staff facilities. HBN 04-01 gives the “best practice” guidance for new healthcare buildings and extension/adaption of existing facilities. The guidelines are applicable to in-patient rooms in most of the settings, including day surgery, acute and community facilities. HBN 04-01 principally provide information to brief and support the NHS projects.

3700

3600

74 The most important part of an in-patient accommodation is the clinical area of the core bed space. The minimum clear space to carry out most activities around bedside can be accommodated within 3600mm (width) x 3700mm (depth) space established by ergonomic studies (Figure 3.14). This space is required to access around the bed for manoeuvring equipment including the bed in and out of the room; transferring patients into and out of bed; moving and handling of patients; and clinical activities including resuscitation. This area does not include space for fixed furniture, storage, preparation and worktops but can include space for door swings. A clinical support zone is required for built-in storage, hand washing, and space for movable equipment (e.g. supply or disposal trolleys). This space should not overlap clear bed space. In HBN 04-01 (2008), 19m2 area was recommended for single-bed rooms [2.5m2 of area increased from HBN 04 (1997)). The height of the space should be 2700mm. The depth and width of the single-bed rooms can vary according to the layout and arrangement of core bed space and clinical support zone. Clinical support zone can be placed in either corridor wall or partition walls.

Each single-bed room should have an en-suite with WC, Shower and wash basin facilities (HBN 04-01, 2008; AIA, 2006). The size of the en-suite illustrated in HBN 04-01 (2008) is 4.5m2 (2285mm x 2100mm) with a chamfered profile (Appendix B). Temporary manoeuvring space to assist a patient from both sides of the WC should be provided and can overlap the bed space and go beyond the enclosed area. The location of the en-suite has a major influence on the in-patients room access point, floor area, privacy, views to and from the bed, and daylighting potentiality of the rooms. Based on the best practice, NHS recommended four example layouts of en-suite location in combination of an in-patient room (Appendix B). According to the suitability of layout, in terms of viewing and daylighting potentiality, four example layouts illustrated in HBN 04-01 (2008) were ranked from 1 (best) to 4 (worst) for this research (Figure 3.15) and are described below.

1. In-between en-suite: this is the best location of the interlocking en-suites, as