In order to speed up the development of health, energy-efficient buildings, the City of Stockholm has formulated a programme for the building of apartment houses. The programme describes the characteristics the buildings should possess in order to achieve the political objectives of energy efficiency, health safety and reduced impact on the environment. These characteristics are described in the form of general functional requirements which provide a good deal of freedom in the choice of technical solutions,.

High quality is a prerequisite for industry to sell its products. To secure an optimized production and at the same time assure a minimum of wastage, it is often required that the production takes place in an environment where control is exerted on the particle concentration in the air and also on thermal conditions. Medical production is subjected to requirements from the authorities to comply with definite requirements of purity, according to the pharmaceutical in question.

A new ventilation and cooling system called OKOMAIR has been developed and investigated. The main idea is to separate carrying off cooling loads and providing fresh air to the occupants without mixing it with the return air. Return air is cooled by fan coil devices. The undiluted outside air is provided directly to the working zone and cooled by a cold waterstorage. This storage is charged by cool outside air during night. Use of the new system leads to high comfort for the occupants and reduces cooling energy.

The momentum balance on a centrifugal fan, supplemented by a complete energy balance for rigorous interpretation of power-pressure interactions, relates these variables to flow rate and fan speed. Non ideal behaviour is modeled by direct mechanical interpretation and by engineering correlation, leading to more general expressions than provided by the fan laws. First attempts to fit these expressions to measured data show promise but reveal limitations of current practice in the data collection and reporting process.

Total energy exchangers with a rotating heat storing matrix have been applied to air conditioning systems for more than 25 years with very good results for saving both heating and cooling energy. The efficiency of the hygroscopic coating of the rotors is very important to recover the latent energy, but there is the risk of cross contamination. To prevent odour transfer, the mechanism of the sorption and desorption process has to be investigated in detail.

Dynamic insulation stands for an insulation through which an air flow flows. The air flow is usually the normal ventilation flow. The air can flow in the same or in the opposite direction of the normal heat flow. The dynamic insulation can be arranged as single where only inlet or exhaust air passes the insulation, or as combined where inlet and exhaust air pass one half of the insulation each. Dynamic insulation using exhaust air might result in condensation problems in cold climates.

Existing regulations concerning the design and construction of residential buildings which are naturally ventilated via courtyards and lightwells have origins in daylighting rather than in aerodynamics. The design of narrow, high-sided courtyards which achieve healthy . conditions for occupants, has long been a problem and a subject of various guidance and research, although many doubts and gaps in knowledge still remained. The work described below resolves these problems, and the coherent theory developed may lead to clearer guidance on the design of courtyards for natural ventilation.

The growing diffision of small power, gas-fired individual units for space heating and service hot water production, as well as concern about operational safety issues, has promoted greater attention to the understanding of ventilation mechanisms in the dwellings equipped with such units. Within a joint research project between Politecnico di Torino and Italgas, an experimental campaign has been conducted in order to investigate the influence of purpose-provided ventilation openings (sized according to the national UNI-CIG 7129-72 standard) on air changes and IAQ.

The major objective of the IEA task XIII project is to design and construct low energy dwellings which should be technically and economically realistic in the period 2000-2010. The design criteria for the Belgian dwelling are the following: - low energy demand for heating purposes; - good thermal comfort conditions, as well in winter as in summer with attention to the problem of overheating; - very good airtightness (n50 <= 1 h^-1); - good indoor air quality conditions; - attractive design for majority of potential clients; - only use of realistic technical solutions.

This paper shows the extensive influence of humidity on comfort, cooling load and refrigeration capacity. Modern computer programs allow an effective consideration of humidity in systems.