Evidence for heat losses via party wall cavities in masonry construction

This paper presents empirical evidence and analysis that supports the existence of a significant heat loss mechanism resulting from air movement through cavities in party walls in masonry construction. A range of heat loss experiments were undertaken as part of the Stamford Brook housing field trial in Altrincham in the United Kingdom. Co-heating tests showed a large discrepancy between the predicted and measured whole house heat loss coefficients. Analysis of the co-heating results, along with internal temperature data, thermal imaging and a theoretical analysis indicated that the most likely explanation for the discrepancy was bypassing of the thermal insulation via the uninsulated party wall cavities. The data show that such a bypass mechanism is potentially the largest single contributor to heat loss in terraced dwellings built to the 2006 revision of the Building Regulations. A comparable convective heat bypass associated with masonry party walls was identified in the late 1970s during the course of the Twin Rivers Project in the United States, albeit in a somewhat different construction from that used at Stamford Brook. A similar effect was also reported in the United Kingdom in the mid 1990s. However, it appears that no action was taken at that time either to confirm the results, to develop any technical solutions, or to amend standards for calculating heat losses from buildings. Current conventions for heat loss calculations in the United Kingdom do not take account of heat losses associated with party walls and it is suggested by the authors that such conventions may need to be updated to take account of the effect described in this paper. In the final part of the paper, the authors propose straightforward solutions to prevent bypassing of roof insulation via party walls by for example filling the cavity of the party wall with mineral fibre insulation, or by inserting a cavity closer across the cavity in the plane of the roof insulation.Practical application: The heat bypass mechanism described in this paper is believed by the authors to contribute to a significant proportion of heat loss from buildings in the UK constructed with clear cavities such as those found in separating walls between cavity masonry dwellings. It is proposed that relatively simple design changes could be undertaken to eliminate such heat loss pathways from new buildings. In addition, simple and cost effective measures are envisaged that could be used to minimise or eliminate the bypass from existing buildings. Such an approach could give rise to a significant reduction in carbon emissions from UK housing

Low carbon housing: lessons from Elm Tree Mews

This report sets out the findings from a low carbon housing trial at Elm Tree Mews, York, and discusses the technical and policy issues that arise from it. The Government has set an ambitious target for all new housing to be zero carbon by 2016. With the application of good insulation, improved efficiencies and renewable energy, this is theoretically possible. However, there is growing concern that, in practice, even existing carbon standards are not being achieved and that this performance gap has the potential to undermine zero carbon housing policy. The report seeks to address these concerns through the detailed evaluation of a low carbon development at Elm Tree Mews. The report: * evaluates the energy/carbon performance of the dwellings prior to occupation and in use; * analyses the procurement, design and construction processes that give rise to the performance achieved; * explores the resident experience; * draws out lessons for the development of zero carbon housing and the implications for government policy; and * proposes a programme for change, designed to close the performance gap

Airtightness of buildings — towards higher performance: Final Report — Domestic Sector Airtightness

This report constitutes milestone D11 — Final Report — Domestic Sector Airtightness of the Communities and Local Government/ODPM Project reference CI 61/6/16 (BD2429) Airtightness of Buildings — Towards Higher Performance (Borland and Bell, 2003). This report presents the overall conclusions and key messages obtained from the project through design assessments, construction observations, discussions with developers and pressurisation test results. It also summarises discussion on the airtight performance of current UK housing, the implementation and impact of current and future legislation, and identifies potential areas for future work

The Effects of Added Dry Whey on Yield and Acceptability of Cheddar Cheese

Cheese production and sales are a major part of the U.S. dairy industry. Total hard cheese sales have increased 60% in the past 10 yr. Per capita consumption of cheese for the same period has risen from 2.81 kilograms (kg) to 4.03 kg for a 43% increase. In response to greater consumer demand the amount of milk utilized in cheese production has increased markedly during the past quarter century rising from the low of 10% of annual milk production in 1950 to 24% in 1976. This recent increase in cheese production emphasizes the importance of achieving maximum yields of cheese from milk used. The economic burden resulting from increased labor and packing costs make it even more imperative that the greatest possible yields be obtained. Ironically, the current lower solids in milk (2) are resulting in less than 9 to 10% cheese yields from milk that was common 20 yr ago. Attendant to more cheese being manufactured to meet consumer demands, more whey is being produced as a by-product. Whey has often been discarded; its bulk and low solids content make transport any distance uneconomical and promote lack of usage. Because of the large Biochemical Oxygen Demand (BOD), disposal of whey by dumping into lakes, streams, rivers, or pits has been forbidden by the Environmental Protection Agency; and discharging through the municipal sewage system has resulted in .extraordinarily high sewage treatment costs for most cheese plants. This situation has led the dairy industry to seek and consider new ways of utilizing the nutritional and/or functional properties of whey and its components. The total solids contents of milk approaches 13%; that in whey is 6.3%. Liquid whey contains approximately 4.7% lactose, 0.9% protein, 0.5% ash, and 0.2% lactic acid (29, 71). The whey produced in 1975 alone contained 675 million kg of lactose, 135 million kg of protein, 108 million kg of ash, and 27 million kg of lactic acid To recover these solids, whey has been concentrated by reverse osmosis or boiling under vacuum; fractionated by ultrafiltration or electrodialysis; or dried. According to the United States Department of Agriculture (USDA), U. S. whey powder production almost doubled from 183 million kg in 1965 to 347 million kg in 1975. Per capita consumption of dried whey jumped, for a 315% increase, from 0.13 kg in 1960 to 0.54 kg in 1973 (72). The uses for whey· are numerous; but by far the two largest users are the dairy and bakery industries which used 32 and 25%, respectively, of all dry whey produced in 1976 (74). However, only one-half of all whey produced is used; hence, new ways of utilizing whey would be distinctly advantageous to the cheese industry. One objective of this research was to find a process to utilize dry whey powder to increase yields of cheddar cheese. Another objective was to determine whether this addition would affect the curing process and especially if the cheese would meet federal compositional standards and be of satisfactory flavor and body after curing