German

Describes measurements undertaken at the Fraunhofer-Institute fur Bauphysik of the effects of various mean and turbulent air flows under constant air temperature, indoor surface temperature, and humidity, using an anemometer and Laser Differential Interferometer.

Resulting from experiences of a project by the German National Energy Research Foundation (NEFF), and further investigations, a recommendation is presented on the permeability of building envelopes in residential buildings, according to on hand ventilation devices. To find out the permeability, the air leakage at 50 Pa is evaluated. This can be found out with the differentiated pressure reading of the building.

Indoor air pollution is particularly noticeable today, resulting from the improvement of ventilation in building envelopes in order to economise in heat energy, and the consequent reduction of fresh air entry, leading to poorer air quality. The article describes the effect of tobacco smoke on the indoor climate of residential and office buildings and its effects on health, particularly its effect on non- smokers, or the passive effects of smoke.

The recommended limits for formaldehyde in indoor air are 0.1 ppm (0.12mgm-3). There are several ways of measuring the formaldehyde concentration, including sampling tubes. Describes a newly-developed sampling tube measurement technique capable of detecting formaldehyde concentrations from 0.04 to 2.5ppm.

A mathematical model was used to describe the natural ventilation of a modern residential building for various building construction and meteorological data. The calculations showed that exhaust air shafts have a very positive influence and that separate consideration of wind and stack effect on thenatural ventilation of buildings leads to a wrong interpretation. Both major influences must be considered together.

Due to the fact that loss of heat due to transmission is on the decrease, the loss of heat due to ventilation is becoming more important. Heat recovery units must be put into use to decrease the heat loss due to ventilation. If mechanical ventilation systems are used to create a minimum air change rate, air-tight windows are necessary - but if no ventilation grilles are used they are out of place.

Describes various methods for measuring formaldehyde in indoor air.

The dairy plants of type MVA 1930 are compact structures with a floor area of 92mx120m. Despite this size the dairy plants - with the exception of certain special areas - can be naturally ventilated over long periods of time. The pen climate parameters for a mechanically and a naturally ventilated plant of the above mentioned type are essentially similar. It seems, therefore, unfounded to restrict natural ventilation to buildings of a certain width. It is rather the formation of the envelope of the building which should be seen as the deciding criterion.

Compares the guidelines for indoor air quality and minimum ventilation rates outlined in the DIN 1946 and ASHRAE standards. Discusses air quality-controlled ventilation. Outlines the principles and standards governing both natural ventilation and controlled ventilation with heat recovery in residential buildings.

Discusses the concept of ventilation efficiency. Sources of moisture production in residential buildings are given, and the minimum ventilation requirements for moisture removal are presented for a typical 3 person dwelling for various outdoor temperatures.