Abstract. Measurements of temporal and spatial changes to indoor contaminant concentrations are vital to understanding pollution characteristics. Whilst scientific instruments provide high temporal resolution of indoor pollutants, their cost and complexity make them unfeasible for large-scale projects. Low-cost monitors offer an opportunity to collect high-density temporal and spatial data in a broader range of households. This paper presents a user study to assess the precision, accuracy, and usability of a low-cost indoor air quality monitor in a residential environment to collect data about the indoor pollution. Temperature, relative humidity, total volatile organic compounds (tVOC), carbon dioxide (CO2) equivalents, and fine particulate matter (PM2.5) data were measured with five low-cost (“Foobot”) monitors and were compared with data from other monitors reported to be scientifically validated. The study found a significant agreement between the instruments with regard to temperature, relative humidity, total volatile organic compounds, and fine particulate matter data. Foobot CO2 equivalent was found to provide misleading CO2 levels as indicators of ventilation. Calibration equations were derived for tVOC, CO2, and PM2.5 to improve sensors' accuracy. The data were analysed based on the percentage of time pollutant levels that exceeded WHO thresholds. The performance of low-cost monitors to measure total volatile organic compounds and particulate matter 2.5 µm has not been properly addressed. The findings suggest that Foobot is sufficiently accurate for identifying high pollutant exposures with potential health risks and for providing data at high granularity and good potential for user or scientific applications due to remote data retrieval. It may also be well suited to remote and larger-scale studies in quantifying exposure to pollutants.

a b s t r a c tThis paper describes the concept development and work to date, of an innovative 'true' building integrated wind turbine. The context for this is the role of small-scale renewable energy in addressing climate change. In the UK a number of small wind turbines have reached the market, however, in almost all cases, these are existing HAWT or VAWT tower mounted systems. Due to their inherent design qualities, and issues such as planning requirements, these have much reduced output due to their form and siting and are unable to take advantage of augmented airflow around buildings.The Crossflex proposal is a radical new development of a Darrieus turbine form. As well as having a technically innovative flexible blade system, it also utilises a lightweight cowling system that can provide both augmented airflow and improved visual integration into new and existing building forms. It is a modular form that can be sited on ridges and corners of buildings to provide useful levels of generation.

There is growing awareness of the overheating risks in new-build properties in the UK. However, this tends to be considered a problem principally for the southern regions in the UK, only becoming a serious issue in the North of England in the medium term and in the long term for Scotland. This notion tends to be largely predicated upon climate change predictions, differences in latitude and summer air temperatures. This paper describes the results from Building Performance Evaluation (BPE) studies over a two-year period from 26 occupied new-build homes across Scotland which demonstrated incidences of overheating.Results suggest that low energy buildings are susceptible to overheating despite northerly latitudes, with 54% of houses studied overheating for more than six months annually, and 27% of homes overheating for less than 10% of the year.Evidence indicated that commonly used prediction tools do not appear to adequately anticipate overheating. This paper maps common overheating causes due to design and the role of occupants, identifying the risks due to the regulatory system, prediction and procurement processes, and the design and construction.A common finding was that design and occupancy factors appear to greater impact on overheating more than location and climatic factors.

Abstract:Building more air-tight dwellings is having a deleterious impact on indoor air quality. In a range of recently completed dwellings CO2 concentrations were measured in occupied bedrooms at unacceptable concentrations (occupied mean peak of 2317ppm and a time weighted average of 1834ppm range 480 -4800ppm). Such high levels confirm that air tight dwellings with only trickle ventilators as the 'planned' ventilation strategy do not meet the standards demanded by the Building Regulations. Reducing ventilation rates to improve energy efficiency and lower carbon emissions, without providing a planned and effective ventilation strategy is likely to result in a more toxic and hazardous indoor environment, with concurrent and significant negative long term and insidious impacts on public health. Furthermore, the methodology underpinning the current regulations cannot be considered as creditable. Any researchers operating in this field require to recognise that dwellings have internal doors. (6) and Crump et al (7) , who called for further investigations to ascertain 'healthy' ventilation rates. This was partially addressed in a recent study (8) commissioned by the Scottish Government, "The effect that increasing air-tightness may have on air quality within dwellings". In this study air tightness and air change rates were measured in a mid-terrace dwelling (Garston, Watford) under a variety of conditions and the published report concluded that dwellings built to 5m 3 /m 2/ /hr@50Pa provide air change rates roughly in line with the CIBSE (9) recommendation of 8l/s per person. BRE test results 2.1In a mid-terrace dwelling, with an air tightness reduced to 6m 3/ /m 2 /hr@50Pa with standard trickle vents fitted on all windows, ventilation rates were measured at 0.7 to 1.3ach -1 on the upper floor (equating to 37-69 l/s), and 0.4 to 0.6 ach -1 on the ground floor (equating to 21-32 l/s). Measurements of CO 2 concentrations (released from a mechanical source) did not provide any cause for concern and settled at circa 1000ppm in the living room and 600ppm in bedrooms. 2.2 3.2The living room and double bedroom were repeatedly pressure tested with the MHVR system outlets/inlets sealed and the system disconnected from the power supply. By progressively increasing the opening area of an additional vent in the tarpaulin, the target air leakage/infiltration rate of 5m 3 /m 2 /hr@50 Pa was achieved. The rooms were then re-occupied Four data sets were collected over two 24hours occupied periods. The initial set measured CO 2 , temperature and humidity -with the MHRV system disabled -between 1800-2200hrs in the living room and 2300-0700hrs in the master bedroom The second two data sets measured the same parameters with the MHRV system re-activated. ResultsGraph 1:Living room MHRV disabled Graph 2: Bedroom MHRV disabled 4. Discussion 4.1 When the living room door is closed and the room occupied by 2 adults and 3 children, CO 2 levels climbed at a rate of 514ppm/hour, peaking at just over 2600ppm. At this time the children star...

The need to reduce carbon emissions and fuel poverty has led to increased building envelope air tightness, intended to reduce uncontrolled ventilation heat losses. Ventilation strategies in dwellings still allow the use of trickle ventilators in window frames for background ventilation. The extent to which this results in “healthy” Indoor Air Quality (IAQ) in recently constructed dwellings was a concern of regulators in Scotland. This paper describes research to explore this. First a review of literature was conducted, then data on occupant interactions with ventilation provisions (windows, doors, trickle vents) gathered through an interview-based survey of 200 recently constructed dwellings, and measurements made on a sample of 40 of these. The main measured parameter discussed here is CO2 concentration. It was concluded after the literature review that 1000 ppm absolute was a reasonable threshold to use for “adequate” ventilation. The occupant survey found that there was very little occupant interaction with the trickle ventilators e.g., in bedrooms 63% were always closed, 28% always open, and in only 9% of cases occupants intervened to make occasional adjustments. In the measured dwellings average bedroom CO2 levels of 1520 ppm during occupied (night time) hours were observed. Where windows were open the average bedroom CO2 levels were 972 ppm. With windows closed, the combination of “trickle ventilators open plus doors open” gave an average of 1021 ppm. “Trickle ventilators open” gave an average of 1571 ppm. All other combinations gave averages of 1550 to 2000 ppm. Ventilation rates and air change rates were estimated from measured CO2 levels, for all dwellings calculated ventilation rate was less than 8 L/s/p, in 42% of cases calculated air change rate was less than 0.5 ach. It was concluded that trickle ventilation as installed and used is ineffective in meeting desired ventilation rates, evidenced by high CO2 levels reported across the sampled dwellings. Potential implications of the results are discussed.