Describes the main tasks of air conditioning, heat load from human bodies, humidity and comfort, influence of the humidity on refrigeration capacity and refrigeration systems for A/C. It concludes that A/C technology is changing, especially in the comfort part by considering the influence of the humidity. One of the main developments in energy savings is the separation of dehumidification and transport of sensible heat gains.
Office workers continue to complain about air quality problems, and a significant industry has developed to measure pollutants and environmental conditions such as temperatures and humidity. The effectiveness of the ventilation system is often ignored because it is a difficult measurement to carry out and interpret. The results contained in this paper make a start towards understanding the performance of mechanical ventilation in New Zealand office buildings.
Depending on the demands regarding the size and location of the occupation zone and the need for outdoor air flow rates, different ventilation systems and air supply devices have to be used in different kinds of buildings. The occupation zone in a residential building can be dficult to define, as many different activities can take place. Furthermore the hrnishings of the room can change with time. The highest air velocities and the lowest air temperatures in the occupation zone will often occur close to inlet air devices.
A study of the reliability of systems by considering the ability of different systems to maintain a required air flow rate over time is included in a subtask of IEA Annex 27 "Evaluation and Demonstration of Domestic Ventilation Systems". Measurements were performed to determine the variation in ventilation rates due to variation in climate and variation in performance of the ventilation system. The monitoring was carried out in one-family houses and apartment buildings, which are representative of the Swedish housing stock.
This paper describes the results of a series of tracer gas tests performed in the mining community of Schlema in eastern Germany. The purpose of these tests was to determine the influence of various mechanisms and subterranean features on the radon levels in the ambient air and in the buildings of the community. Under the former Democratic Republic of Germany (the DDR regime), the mines in and near Schlema and in the ore mountains in Sachsen were an importance source of uranium. These mines have now been closed down and the area is currently under remediation.
The paper presents the results of a simulation study performed by means of the COMIS multizone infiltration and ventilation model. The simulations were carried out for a two-storey single-family passive-stack-ventilated house in a cold climate (Stockholm, Sweden). Main conclusions of the study include the following: it is possible - during at least 75 % of the heating season - to achieve a ventilation rate in the whole house of at least 0.5 ach or approx. 30 l/s only if the house has a leakage rate above approx.
Three ventilation systems were installed in the EA Technology Ventilation Test House: passive stack ventilation (PSV), mechanical ventilation with heat recovery (MVHR) and extract fans. Humidifiers were used to simulate occupancy and the performance of the systems monitored over the winter of 1993/94. The aim was to assess the effectiveness of different ventilation systems in controlling indoor humidity at a level that will inhibit the growth of house dust mites.
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