The effects of an air conditioning system for office buildings were studied experimentally and computationally. A displacement ventilation system was used as the main air-conditioning system, and a partition with a built-in circular fan was used to deliver the air-conditioned clean air near the floor supplied by the main displacement system to the occupant in the office directly.

This contribution reports on investigations about the performance of decentralised ventilation units with heat recovery. Such units can be easily installed in individual rooms and therefore offer an interesting alternative to central ventilation units. Nevertheless these units exhibit some problems. Experimental examinations of two commercial decentralised units showed that the real effectiveness of heat recovery was always below 50 % and that considerable leakage between the air ducts can result in poor indoor air quality.

This paper proposes a new personal air-conditioning system, which modifies a common partition used in offices to a partition-type fan-coil unit (PFCU) with inlets and outlets on its surfaces. Chilled water is supplied as the cooling energy, and is delivered to the partitions by pipelines incorporated into the structure. Hence, conventional air conditioning systems using ceiling-based air diffusers for open-plan offices may be dispatched into several small individual systems controlled by the occupants.

This study compares indoor climate, cooling efficiency and energy consumption of an underfloor air distribution system and a ceiling-based system in a test chamber. Floor-based system appears to provide better thermal conditions with lower electricity consumption.

The study conducted by the US Government Accounting Office in 1995 says that 25 % of the nation’s schools are plagued by IAQ problems, even higher percentage of schools having IAQ problems is reported by the Environmental Protection Agency (Johnston and D

This paper proposes a new mode of ventilation for indoor airflow. Computational results show that with properly designed supplied air velocity and volume, locations of diffusers and exhausts, the proposed system should be able to maintain better thermal comfort with a smaller temperature difference between the head and foot level, and possibly lower energy consumption, if compared with conventional systems. It looks promising that better indoor air quality (IAQ) in the breathing zone could also be achieved but that further work is needed to determine if IAQ benefits are significant.

CFD calculations were used to compare temperature and air velocities in an environmental chamber equipped either with a conventional comfort overhead air supply system or with an underfloor supply system. Results show the advantages of underfloor system to provide adequate temperature, velocities and turbulence in the seated zone.

Tests were operated to analyse thermal stratification with undefloor air distribution systems supplying air at different rates and temperatures.

Literature was reviewed about underfloor systems and engineers having experienced these systems on completed projects were interviewed. Underfloor air distribution systems improve thermal comfort , indoor air quality and user satisfaction.

Natural ventilation’s fluctuating airflow has impacts on the thermal comfort and VOCs transportation in the naturally ventilated buildings. Research about the fluctuating characteristics of the airflow in naturally ventilated buildings was carried on in t