Buildings generate nearly 30% of global carbon emissions, primarily due to the need to heat or cool them to meet acceptable indoor temperatures. In the last 20 years, the empirically derived adaptive model of thermal comfort has emerged as a powerful alternative to fixed set point driven design. However, current adaptive standards offer a simple linear relationship between the outdoor temperature and the indoor comfort temperature, assumed to sufficiently explain the effect of all other variables, e.g. relative humidity (RH) and air velocity. The lack of a signal for RH, is particularly surprising given its well-known impact on comfort. Attempts in the literature to either explain the lack of such a signal or demonstrate its existence, remain scattered, unsubstantiated and localised. In this paper we demonstrate, for the first time, that a humidity signal exists in adaptive thermal comfort using global data to form two separate lines of evidence: a meta-analysis of summary data from 63 field studies and detailed field data from 39 naturally ventilated buildings over 8 climate types. We implicate method selection in previous work as the likely cause of failure to detect this signal, by demonstrating that our chosen method has a 56% lower error rate. We derive a new designer-friendly RH-inclusive adaptive model that significantly extends the range of Highlights • The influence of relative humidity on adaptive thermal comfort explained. • A new adaptive thermal comfort model which considers the effect of relative humidity introduced. • The current model is shown to overestimate overheating by 30% over 13 global locations.

Long-term encampment is a growing aspect of a growing refugee crisis. There is hence the need to ensure shelters provide a safe and suitable environment. We present the first field study including social and thermal comfort surveys and physical measurements conducted in Syrian refugee camps in Jordan, during summer and winter. This required the creation of a new Arabic thermal comfort survey based on the numerical ASHRAE scales to ensure the elimination of any ambiguities due to translating the scales. The three analysis methods used (linear, logistic and multiple logistic regression) all gave the same neutral temperature, 23°C; however, Fanger's predicted mean vote model was found to underestimate the adaptive potential of the refugees. The comfort band found using logistic regression ranged from 28.4°C to 17.2°C, suggesting a significant adaptability of the refugees, but not one equal to the temperature range found on site. Issues with the clash between ventilation, privacy, security and sand ingress were identified, and this points to a need to re-evaluate shelter ventilation in general. However, given the extreme conditions recorded, natural cross ventilation alone will not be sufficient in achieving summer comfort. Combining this with the observation that, due to safety and lack of resource, the refugees have no means of heating at night, a shelter solution that successfully includes insulation, and possibly thermal mass would seem important.

As the 2003 European heat wave demonstrated, overheating in homes can cause wide scale fatalities. With temperatures and heat wave frequency predicted to increase due to climate change, such events can be expected to become more common. Thus, investigating the risk of overheating in buildings is key to understanding the scale of the problem and in designing solutions. Most work on this topic has been theoretical and based on lightweight dwellings that might be expected to overheat. By contrast, in this study temperature and air quality data were collected over two years in vulnerable and non-vulnerable UK homes where overheating would not be expected to be common. Overheating was found to be occurring, and disproportionally so in households with vulnerable occupants. Since the summers in question were not extreme and contained no prolonged heat waves this is a significant and worrying finding. The vulnerable homes were also found to have worse air quality and this suggests that some of the problem might be solved by enhancing indoor ventilation. Finally, the collected thermal comfort survey data were validated against the European adaptive model. Results suggest that the model underestimates discomfort in warm conditions, having implications for both vulnerable and non-vulnerable homes.

In light of recent research, it is evident that occupants are playing an increasingly important role in building energy performance. Around the world, a driving factor for how buildings are designed-and operated in some cases-is the local building codes. Yet, occupant-related aspects of building energy codes have traditionally been simple because: 1) occupants are often seen as a source of uncertainty that cannot be reconciled by current code methodologies and language, and 2) the codes have not kept up with the recent surge of interest and importance of occupants. This paper provides a review of 22 international building energy codes and standards by first comparing quantitative aspects and then analyzing rules and approaches mandated by the codes. The review of requirements for prescriptive and performance path requirements revealed a wide range of occupant-related values, approaches, and attitudes. For example, a key value such as occupant density varies by nearly a factor of three between countries' codes, which among other things underlines the need for development of locally tailored occupant behaviour models for future occupant-centric building performance standards and codes. Moreover, occupants are often referred to only implicitly; the level of optimism that occupants make energy-saving actions varies greatly; and, only a few codes address occupant feedback and system usability. Based on the findings, a set of initial recommendations for future building energy codes is made. The focus in this paper is offices, though the general recommendations are applicable to other building types.