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Air permeability of ceiling linings is an important element in understanding air and moisture flux from living spaces into the roof cavity. Ideally, these two spaces are decoupled to avoid transportation of moist indoor air into the attic space, where it can lead to condensation on the cold roof cladding. The purpose of this paper is to experimentally characterise the air permeability of a variety of common ceiling types. The results are given as leakage functions. Characteristic leakage data are also given for several ceiling penetrations. A case study illustrates the relevance of these data.

A specially designed test facility allows the installation of different ceiling types of up to 38 m² in area. Laminar flow elements are used to measure the volumetric flow across the ceiling while recording the pressure difference. The experimental data are fitted to the leakage function equation Q =c (ΔP)ⁿ. Ceiling penetrations are characterised in a similar way. For the case studies estimating the transport of moisture into the roof cavity, indoor climate data have been obtained using humidity and temperature sensors.

Air leakage functions are given for a number of common ceiling linings and ceiling penetrations. These data can be used in simulations aimed at modelling moisture flux into the roof cavities. In the case study, the authors also give indoor climate data of residential dwellings in New Zealand.

This paper addresses the need for robust ceiling air permeability data in whole-house temperature and moisture transport simulations.

Accurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.

Fifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.

The eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the “divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.

The findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the “divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.

Direct measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

CF6–50A engines have been selected to power the European A300B aircraft scheduled for certification and airline delivery in 1974.

Mechanical ventilation with heat recovery (MVHR) is increasingly being promoted in the UK as a means of reducing the CO₂ emissions from dwellings, and installers report growing activity in the retrofit market. However, the airtightness of a dwelling is a crucially important factor governing the achievement of CO₂ reductions, and the purpose of this paper is to understand the technical implications of airtightness levels in an experimental dwelling, purpose built to typical 1930s standards, at the same time as gaining the users’ perspectives on airtightness and ventilation in their homes.

In‐depth interviews were carried out with 20 households to collect information on their retrofit and improvement strategies, attitudes to energy saving and their living practices as they impinge on ventilation. The experimental house was sealed in a series of interventions, leading to successive reductions in the air permeability as measured by a 50 Pa pressurisation test. The behaviour of a whole‐house MVHR system installed in the experimental house, was simulated using IES Virtual Environment, using a range of air permeability values corresponding to those achieved in the retrofit upgrading process.

In the house considered, air permeability must be reduced below 5 m³/m²h for MVHR to make an overall energy and CO₂ saving. However, to achieve this required a level of disruption that, on the basis of the views expressed, would be unlikely to be tolerated by owners of solid wall dwellings.

The paper is the first to combine results from a user‐centred approach to exploring the existing practices of householders with a simulation of the energy and CO₂ performance at different levels of airtightness of an experimental house in which MVHR has been installed.

Reviews the UK government’s proposals for amending the energy efficiency of new dwellings. With the aid of worked examples the alternative calculation methods for U‐values are demonstrated. The author concludes that the new methods are cumbersome to calculate by hand and that where there is only one bridged layer the difference between the old and new methods is negligible. It is envisaged that manufacturers and SAP providers will quickly provide new calculation suites to enable designers to undertake calculations effectively and easily.

New Zealand’s historical housing stock comprises largely single-storey detached houses, characterised by poor winter comfort with high air infiltration. Challenges with affordability and land use are shifting New Zealand’s housing stock towards double-storey, conjoined medium-density housing (MDH). Reduced external surfaces in this typology should reduce winter heat loss and infiltration, improving winter comfort and health. New concerns arise, however, regarding summertime overheating and poor indoor air quality.

A field study was undertaken where temperature, humidity, airtightness, particulate matter (PM) and total volatile organic compounds (TVOC) were measured in two unoccupied, newly built double-storey, conjoined houses, for several weeks over summer.

The reduced surface area of this typology did not reduce infiltration and demonstrated significant periods of overheating. Internal PM concentrations generally exceeded outdoor concentrations but did not exceed annual average outdoor PM10 guidelines of 20 µg m-3. Infiltration factors (Finf) were closer to more traditional houses. TVOC readings varied widely, but frequently exceeded international guidelines.

The small sample limits the applications of conclusions more widely. Recommendations to investigate a wider sample in different locations with more detailed VOC analysis over all seasons are made.

Improvements to internal environments cannot be guaranteed by housing typology changes alone and must still involve thoughtful environmental design.

Housing typology changes may not improve internal living environments.

A move to the new MDH typology may not achieve expectations of airtightness and thermal improvement. New challenges arise from significant overheating and high TVOC levels, which may lead to new negative health effects.

The main work in the development of airships was done half a century and more ago—yet the potential of airships with improved modern materials and techniques is enormous. Even forty years ago Zeppelins were crossing the oceans to timetables, operating from mooring masts and capable of surviving gales of over 80 mph.

If the building control system is to deliver housing which achieves major reductions in carbon dioxide emissions, it is important to ensure not only that energy efficiency standards are set at an appropriate level but also that the specification of standards takes into account realised performance. It is argued in this paper that, in many cases, there is a large gap between notional performance, as defined by the calculation methods embodied in the Building Regulations, and performance achieved in practice. Although it is accepted that some variation in performance is to be expected, there are a number of areas where closer attention to the methods used to estimate thermal performance, and the inclusion of hitherto unregulated aspects, could help to achieve a much closer match between what is expected and what is achieved. In particular, the paper discusses ways in which the Regulations could be improved so that the impact of thermal bridging, construction quality, window performance and airtightness are more closely controlled.

The purpose of this study is to evaluate an intelligent office building based on the post occupation evaluation (POE) criteria in relation to physical and psychosocial user needs.

Data were collected using a questionnaire. The first group of questions was to determine demographic information; the second group of questions includes questions, which aim to measure the comfort level of the building users. The questionnaire also includes open-ended questions on other comments and suggestions. The data of the research were evaluated with the SPSS program and frequency and percentage distributions were determined. A total of 110 employees participated in the survey.

The results showed that the participants were generally satisfied with the design quality, indoor air quality and building support services quality of the building, while there were also participants who report dissatisfaction about the floor covering materials and ventilation of the spaces. At the end of the study, attention was drawn to the importance of POE in connection with user requirements.

It is considered that this study will shed light on future works by developing a perspective on intelligent office buildings in terms of user requirements and research process with the results obtained.