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In conjunction with IEA Annex 18, DCV-systems, a test on an auditorium in a school in Tyreso south of Stockholm has been carried out. The auditorium has 450 seats on a slightly sloped floor and a ventilation system with low impulse air supply devices placed at the lower (front) part of the auditorium. The system is intended to act as a displacement ventilation system during operation with heat load from people. The flow rate is governed by a CO2 sensor in the exhaust air device. In non-operational state, and if heating is necessary, the system operated with recirculation of air.

Within the framework of demonstration and industrial pilot projects in the energy sector supported by the Commission of the European Economic Communities, an important experiment has been dedicated to the HYGRO-ADJUSTABLE NATURAL VENTILATION (Contrat EE/166/87/FR). The experiment took place on three sites: Les ULIS (France), NAMUR (Belgium) and SCHIEDAM (the Netherlands).

For several years the technology of chilled ceilings has been a favourite issue among HVAC technicians and underwent a boom in the past few years. According to the survey of a German technical journal, on March the first 1993, a total of 308,490 m² of chilled ceilings had been installed in German buildings, out of which 69 per cent had been installed in new buildings and 31 per cent in modernized projects. Cooling ceiling systems are the ideal.application where high demands are placed on comfort requirements and where the energy loads are very high compared to material loads.

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.

In urban non-residential buildings air-conditioning systems are generally required to achieve acceptable air quality. To reduce the energy demand of HVAC-plants free cooling is proposed. The present study deals with free cooling by outdoor air (untreated or additionally cooled by evaporation) during the night. Therefore a sufficient building mass (about 600 to 800 kg/m²) is necessary which stores the heat produced in daytime and which is cooled down at night. In most conventional non-residential buildings, however, the building mass is at about 400 to 600 kg/m².

Ventilation is necessary to insure acceptable indoor air quality as well as to protect the building itself against damage due to condensation Ventilation rates however, must not lead to excessive energy consumption In order to comply with these requirements of hygiene, comfort and energy savings, French regulations stipulate that the ventilation of dwellings has to be general and continuous and achieved by specific systems by which fresh air is provided to the dwellings.

Designing a comfortable inside climate for office buildings to operate within comfort limits (PMV+/-0.5) requires a flexible operating strategy. Two systems a VAV and a VHV are identified and compared to each other. Dynamic simulation techniques are used to obtain an optimal design, based upon comfort conditions not temperatures. The control strategies are optimised to minimize energy consumption while controlling the HVAC system to remain within comfort limits in the occupied zone.

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.