The normally used equation for calculation of infiltration flow rates into a house is a power law of which the exponent n is normally assumed to be 0.66 but sometimes values of 0.5 or even 1 can be seen in the literature. In this paper the constant n is calculated assuming a non fully developed infiltration flow. The constant n will for this assumption take values between 0.67 and 0.77 if the slots where the flow takes place are long enough to get a flow close to a developed one.
This paper discusses the potential for achieving an "energy-efficient" ventilation system by improving design procedures for natural ventilation. It considers ventilation requirements and the meaning of the term energy-efficient ventilation. Both of these topics are of fundamental importance to any design procedure. Natural and mechanical ventilation systems are discussed. This is done because natural ventilation is often compared unfavourably with purpose-built mechanical systems. It is argued that such comparisons can be misleading, unless all aspects are considered.
Natural and forced ventilation are directly and indirectly influenced by the pressure distribution around a building. Results of full-scale pressure measurements on a typical Swedish timber house are presented. The rate of air infiltration has been calculated by employing the values obtained from full-scale pressure distribution, air leakage characteristics and temperature differences. The results are compared with the actual ventilation obtained from tracer gas measurements.
The investigation was divided into several parts: 1, measurements of a mechanical ventilation system, 2, calculation model for this system, 3, measurements of the air leakage of the facades of a flat and 4, calculation model for this flat.
The purpose of the project has been to determine the saving in energy obtained in the practical operation of an FTX-system -that is, a fan-controlled supply and exhaust ventilation system with heat recovery - compared to an F-system, which is solely a fancontrolled exhaust system. The investigation, carried out in a terrace-house district in Skellefteg, showed the following savings for the FTX-systems in comparison with the F-systems: in 1-storey houses (81 m², airtightness approx. 1): appr. 1000 kWh/year in 2-storey houses (99.5 m², airtightness approx. 3) : appr. 1250 kWk/year.
The aim of the present study is to measure the possible health effects among tenants after certain characteristic energy conservation measures had been taken in their dwellings. Changes in comfort are also included. It is part of a number of projects on subjects such as indoor pollutant source control and changes in house dust mite populations related to moisture changes in retrofitted dwellings.
Discusses insulation of lofts, roofs, walls, windows and floors, natural ventilation of dwellings and mechanical ventilation with heat recovery in dwellings. Considers cost benefits of weatherstripping and constant-flow ventilators for naturally ventilated houses. Concludes that installation of mechanical ventilation with heat recovery is uneconomic, but adding a heatexchanger to an existing mechanical ventilation system has economic benefits.
Reviews the present state of development of dynamic insulation systems. Describes the advantages and disadvantages and assesses probable applications. Earlier articles and reports on dynamic insulation are listed and commented on. The second part deals with the ventilation design aspects for practical application of dynamic insulation in buildings. One of the points is concerned with how the air flow through the insulation is affected by changing external climate conditions. The risks of condensation in the insulation, particularly with coincident flow systems, is discussed.
Discusses reasons behind occupant ventilating behaviour, such as: 1. general attitudes, particularly regarding energy, 2. occupant requirements, 3. components of the habitat micro-climate, 4. optimum micro-climate and desired micro-climate, 5. means available in the habitat to modify the micro-climate - a. general means, b. ventilation as a specific means, 6. balancing requirements against means, 7.
50 occupants of terraced houses, divided into 4 groups, were surveyed three times in October 1981, February 1983 and March 1983. The first group had Isolair air heating and ventilating systems, and were well insulated with double glazing. The second group was heated by radiators and had the same insulation as group 1. Groups 3 and 4 had normal insulation. Results of the surveys are given. The air heating and ventilating system did not provide the level of satisfaction hoped for. The group with the air heating and ventilating system was surveyed again in March 1984.
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