Presents the results of an investigation carried out on behalf of the Swiss Ministry for Environmental Protection. The main aims were to find acalculation method for the annual energy demand of a building which takes into account solar heat gain and which generates data permitting the effect of thermal protection regulations on energy consumption to be evaluated. Treats the effect on transmission heat loss of outside walls of absorbed solar radiation, the specific heat loss of typical dwellings, reference years based on weather data for energy consumption calculations.
This report is a guide to give the canadian builder practical information in the area of energy conservation in new housing. Offers useful suggestions for planning, designing and building a more energy efficient home. Sections covered include energy use in dwellings, air tightness, ventilation andmoisture control, options for improving the building shell, space heating and cooling systems, and cost considerations. Takes the 1979 Ontario Building Code as the basis upon which to develop and evaluate improvements.
Many mechanically ventilated buildings are over-ventilated since ventilation rates are based on a fixed number of people (often in excess of the average occupancy) and no allowance is made for infiltration. States that the CO2 concentration in the ventilated space can be related to the ventilation rate per person, and by modulating the fresh air flow to maintain a constant CO2 concentration, a constant ventilation rate per person can be obtained.
Reviews a research project which has the objective of establishing:< 1. Expressions for ventilation efficiency< 2. Methods for measuring ventilation efficiency< 3. Rules for acheiving efficient ventilation.< Derives expressions for ventilati
Measurements made in Finland have shown that the airtightness of many small houses is lower then the level of requirements specified in Sweden. States that the most important areas for sealing up external walls in concrete structures are the joints in the internal shell, the joints between concrete and timber structures, and the joints between door and window frames. All these areas can be made airtight by using appropriate materials and construction methods. In general, the air tightness of small concrete houseshas been found to be good and to comply with the specified requirements.
The radon contents in the two wings of a university building in Tampere were measured. Outside air was supplied to the corridors where it flowed to the rooms via ceiling ducts. Lower radon values were obtained in the rooms located close to the air supply end of the corridor. Radon content was also higher on the first floor then on higher floors, probably because of radon emission from the gravel layer in the foundation. Notes that the main source of radon in a wooden building is the ground, and the tightness of the floor construction is therefore very important.
TNO Research Institute for Environmental Hygiene have developed a mathematical model (based on an electrical analogue model) for deciding on the best ventilation system (natural v. mechanical) for a building while it is still atthe design stage. This model has been applied to an auction complex situated at Bleiwijk to deduce the best ventilation system for the building. Conclusions are that a natural ventilation system can be realized by placing ventilating devices exclusively in the roof.
The air tightness of buildings is part of an investigation performed by the State Research Centre of Finland. Regulations are being developed in Finland for the maximum allowable leakage in buildings. These can be stated as 0.2 ach/hr for residences, 0.1 ach/hr for low apartment buildings, and 0.2 ach/hr for high rise buildings. Tightness can be measured using a suitable fan connected to a board in a window or door opening, or by thermography.
In a modern residence with reduced air infiltration, a problem may arise if the fresh air requirement is left to natural leakage. The article discusses this problem, and describes techniques for measuring air leakage and typical results. The contaminants which define the need for ventilation are described and the case for controlled ventilation systems (and possibly heat recovery devices) is made. Areas for further research are recommended.
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