Overheating in vulnerable and non-vulnerable households

Abstract

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.

Can the choice of building performance simulation tool significantly alter the level of predicted indoor overheating risk in London flats?

“…A number of other factors besides air temperature have been identified to influence window operation 54 . In addition, it has been demonstrated that people perceive indoor temperatures and act to change their thermal comfort differently 9,55 . Two other implicit assumptions that fundamentally relate to the binary nature of the assessment and are not addressed in the guidance document are that: (a) the uncertainty of BPS tools and (b) the choice of BPS tool will not significantly alter the prediction.…”

“…A meta-analysis estimated that currently 30% of the world's population is experiencing extreme levels of heat, a figure that may rise to 70% by 2100 if no action is taken to tackle climate change 7 . This would place the elderly and vulnerable (disabled or with long-term illnesses) most at risk 4,8,9 . To tackle these and other potential effects of climate change, international agreements aimed at reducing global carbon emissions have been negotiated 10 .…”

The summer indoor temperatures of the English housing stock: Exploring the influence of dwelling and household characteristics

“…33 The static overheating criteria and mean monitored temperatures over the summer period were used to determine whether significant differences exist due to location, external wall type, age band and building type. However, as suggested by the literature, 27,32,33 numerous other factors could influence the indoor environment. In addition, as the distribution of characteristics (e.g.…”

“…Reproduced from Symonds et al 41 assess overheating risk in previous in-use studies. 27,30,42 A high risk of indoor overheating was assumed if either of the following thresholds is exceeded: 20 1. The percentage of occupied hours where the operative temperature (T op ) exceeds the maximum allowable temperature (T max ) by 1 C or more during the period May to September, inclusive, should not exceed 3%.…”

Overheating and Daylighting; Assessment Tool in Early Design of London’s High-Rise Residential Buildings

“…In the UK, 20% of households may already be at risk of overheating [15], and, with the predicted climate change, this percentage will likely increase [4]. Although no universal definition of overheating exists, the phenomenon has been widely monitored [15][16][17][18][19][20][21][22][23][24], and thermally modelled [25][26][27][28][29][30] using either static or adaptive assessment criteria. Numerous studies have examined a number of dwelling types that represent broadly the housing stock in the UK.…”