English

The "Passivhaus Darmstadt-Kranichstein" is a 4 unit terrace house with an extremely low total annual energy consumption of less than 32 kWh/m² of living area, thereof about 12 kWh are needed for room heating /Feist 1994/. The determinig factors for the low consumption are the superinsulation, airtightness of the thermal envelope in combination with a highly efficient VAV ventilation system, and an improved window construction. The "Passivhaus" therfore is a typical example of an improved low energy house.

Four classrooms of two secondary schools located around Lyon in France have been monitored. The objectives are to analyse the quality of the indoor air and the thermal comfort and also the behaviour of the occupants towards opening of the windows. This paper briefly describes the context and the nature of the monitoring campaign, and presents the results of the measurements with direct interpretation of the ventilation needs.

After a short description of the physical phenomena involved, unified expressions are worked out describing net airflow and net heat flow through large vertical openings between stratified zones. These formulae are based on those of Cockroft for bidirectional flow, but are more general in the sense that they apply to situations of unidirectional flow as well. The expressions are compatible with a pressure network description for multizone modelling of airflow in buildings. The technique has been incorporated in the flows solver of the ESP-r building and plant energy simulation environment.

In the UK the increased use of natural ventilation in buildings is being encouraged, particularly during hot weather as an alternative to air conditioning or mechanical ventilation. In order to take advantage of this option building designers need to be able to estimate potential air flows. Conventional calculation methods assume windows to be simple openings, however in practice the situation is more complex since during hot weather the opening is likely to be shielded by some form of solar shading device.

In order to demonstrate conformity with the current Building Regulations, many house builders are incorporating sumps beneath the ground floor construction of houses within the designated Radon Affected Areas. These sumps will allow for later depressurisation of the below ground floor construction and thereby prevent radon passage to the internal building environment. There are concerns regarding the costs of these measures and also the potential for these sumps to be used by vermin as nesting sites as well as their effectiveness.

The use of PSV (Passive Stack Ventilation) systems in two and three storey dwellings is now widely accepted as a method of achieving adequate ventilation levels for indoor air quality control. However, the application of PSV systems to multiple-storey dwellings is, in the United Kingdom, in its infancy. This paper provides detailed performance data relating to extensive monitoring of PSV systems in multi-storey dwellings in three EC countries (France, Belgium and Holland).

Proper dimensioning of natural ventilation system for multi-storey buildings is a critical matter, because the air flow rate depends on many parameters as outdoor temperature, wind, distribution of air inlets and envelope air leakage, characteristics of outlets and cowls. The computer code GAILNE BIZONE predicts the ventilation rates in multi-storey dwellings equipped with passive stack ventilation system. Each level is treated as a two-zones configuration, but each zone is linked to the collective ventilation shaft of the building.

Terminals are used on all types of ventilation system exhausts, often to prevent rain water and animal entry, but also to prevent wind induced flow-reversal and enhance wind induced updraught. There are many different terminal designs available displaying a wide range of characteristics. This report discusses a terminal testing and rating method. The tests highlight terminal wind performance as well as terminal resistance to the exhaust flow. The terminals are ranked according to loss coefficients and wind performance which allows them to be matched more closely to system requirements.

In certain parts of the United Kingdom where radon gas seeps from the ground into the basement of domestic housing, normal methods of removing this gas by using under floor extract ventilation is not appropriate. In this situation the radon gas enters the basement through the side walls of the cellar and hence into the house. Using mechanical ventilation to either pressurise or de-pressurise the cellar may be an appropriate solution to this problem, however before installing such a system in a house a ventilation strategy must be established.

Multifamily buildings with natural ventilation are still being built and exploited. Such buildings are often equipped with individual gas-fired water heaters located in windowless bathrooms. It implicates the possibilities of improper gas exhaust as a result of the decrease of infiltration, what could be sometimes even harmful for the occupants' health. Based on the numerical simulations, analysis of ventilating air flows in typicalmultifamily dwelling house will be carried out.