# High-Rise Social Housing in Hot-Humid Climates: Towards an 'Airhouse' Standard for Comfort
## 2 Materials and Methods
In contrast to the PPR Beringin, lightwells are the main source of natural lighting and ventilation for the bedrooms, kitchens, and bathrooms facing towards the corridor (Figure 7). The building has single-glazed casement windows. Six house units were selected in block A to represent the block's lower, intermediate, and upper zones. Three of the units are facing unobstructed open areas and another three are facing an obstructed open area (Figure 8). The existing relevant regulations, standards, and the green rating tools used in Malaysia were studied and compared [3]. In Malaysia, the standard that sets the indoor design conditions for air temperature, relative humidity, and airspeed is MS1525. Unlike the CIBSE and ASHRAE standards, these design conditions are for air-conditioned spaces only. Figure 9 shows the comfort zone (green area) for Kuala Lumpur on a psychrometric chart, according to ASHRAE 55 and CIBSE guide A, in relation to MS1525. This zone is the benchmark for the study and is used for future comparison in this research. In accordance to it, the comfort criteria in Kuala Lumpur are an operative temperature between 24-28 \({}^{\circ}\)C, 40-70% relative humidity, and a 0.15-0.50 m/s airspeed [13; 14] (Table 2). For air quality, the World Health Organization (WHO) has set annual limits: PM10 \(<\) 20 \(\upmu\)g/m\({}^{3}\) and PM2.5 \(<\) 10 \(\upmu\)g/m\({}^{3}\). For a 24 h period, the limit for PM10 is 50 \(\upmu\)g/m\({}^{3}\) and PM2.5 is 25 \(\upmu\)g/m\({}^{3}\)[15]. CO\({}_{2}\) is one of the parameters measured, and the limits for the gas, according to CIBSE KS17 and the Department of Environment in Malaysia (DOE), are 5000 ppm and 1000 ppm, respectively. The DOE's limit is to indicate the adequacy of ventilation in any particular room. Hence, readings above this limit show an indication of inadequate ventilation [16]. CO, another gas measured in this study, has different limits set by CIBSE, ASHRAE and the DOE, which are 26 ppm, 35 ppm and 30 ppm, respectively. Figure 8: Site section of the PPR Seri Aman. Figure 7: Typical floor plan of the PPR Seri Aman (a second generation building). The methodology used in assessing comfort in the indoor environments follows the ASHRAE Standard 55 ('Thermal Environmental Conditions for Human Occupancy') recommendations [14] (Table 3). The measuring conditions during the cooling period (summer conditions) have been used due to the local hot and humid climatic conditions. There were two campaigns of fieldwork in the two case studies and a computational simulation model. The first fieldwork was carried out between the 11 th and 29 th of July, 2017, when the southwest monsoon was active. This monsoon runs from May to September every year and provokes relatively dry weather, with an average prevailing wind speed (coming from the southwest) usually below 15 knots (7.7 m/s) [17]. Carrying out the necessary fieldwork during this dry season is highly recommended, due to the high temperatures which usually occur in this period every year. The fieldwork was carried out during the two main seasons (dry and wet) in Malaysia, so they do not represent the whole-year thermal comfort data of Kuala Lumpur. Therefore, simulation modelling using Integrated Environmental Solutions (IES) was used to evaluate the full-year data. This affordable software is suitable for simulating naturally ventilated buildings through its 'Macroflo' and 'Apache' modules for the detailing of the building systems, simulating and calculating the environmental conditions of a 3D model. For air quality, simulation software that could look at the concentration of air pollution substances (i.e., CO, SO\({}_{2}\), benzene and particulate matter) was not available yet. Thus, the fieldwork results (indoor and outdoor conditions) and the full-year data of air quality in Kuala Lumpur (outdoor conditions only) were used for further comparative purposes [18].