An increasing impact of ventilation and air-conditioning to the total energy consumption of buildings has drawn attention to natural ventilation and passive cooling. The very common way of natural ventilation in residential buildings is passive stack ventilation. The passive stack ventilation relies on the stack effect created by the temperature difference between air temperature inside and outside a building.
Sheffield City Council in the UK identified some dwellings of non-standard construction that needed to be refurbished. The refurbishment mainly involved applying insulation and rendering to the exterior surfaces of external walls and replacing old windows. The main aims of the refurbishment for the Council were to improve the condition and appearance of the dwellings and reduce conductive heat loss through the fabric.
Duct leakage in forced-air distribution systems has been recognized for years as a major source of energy losses in residential buildings. Unfortunately, the distribution of leakage across homes is far from uniform, and measuring duct leakage under normal operating conditions has proven to be difficult.
In so far as natural ventilation system is totally dependent on local weather conditions and building facade elements, housing ventilation cannot be permanently guaranteed. This paper offers a computational flow simulation (CFD) which can be used to analyze housing ventilation under different buildings and weather conditions.
Twenty homes were tested and monitored in Houston, Texas, U.S.A. to evaluate humidity controlperformance and operating cost of six different integrated dehumidification and ventilation systems that could be applied by production homebuilders. Fourteen houses had one of the six integrated dehumidification and ventilation systems and also met a high standard of energy efficiency criteria.
In January 2002 the EU RESHYVENT project started, a three-year project within the EU Fifth Framework Programme on the investigation and development of demand controlled hybrid ventilation systems in residential buildings. The project is a clustering of four industrial consortia with a multi-disciplinary scientific consortium. Each of these industrial consortia will develop a working prototype of a hybrid ventilation system for a specific climate.
In France, ventilation in new residential buildings must be designed and dimensioned according to the Health regulation (Arrêté du 24 mars 1982) which is basically based on required extract air flow rates. Two points are to be noticed : 1) The extract flo
Mold in dwellings is a persisting complaint in moderate climates. Nine parameters intervene in it: (1) climate, (2) inside temperature, (3) vapor release, (4) ventilation, (5) lay out, (6) envelope thermal performance, (7) sorption inside, (8) presence of preferential condensation surfaces and (9) type of finish. Exterior climate acts as boundary condition while inside temperature, vapor release and ventilation belong to the living habits. The five others are design and construction related.
The knowledge of indoor air humidity in the design phase is important to decide on the appropriate moisture control measures to prevent moisture problems in building components. Because of the uncertain nature of most of the factors affecting the indoor humidity, its accurate prediction in the design phase is not possible. To overcome this problem, the concept of Indoor Climate Classes has been introduced and used in Europe since its early development in the Netherlands in the 1970s up to its recent introduction in a European Standard on the hygrothermal performance of building components.
Airflow through houses from onshore coastal breezes in warm humid tropical climates is the principal passive means of achieving indoor thermal comfort when air temperatures exceed 30°C and relative humidity exceeds 60%. Estimates of indoor natural ventilation cooling potential have been based on indoor wind speed coefficients determined from boundary layer wind tunnel tests combined with wind frequency, air temperature and relative humidity data.
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