Two series of formaldehyde concentration measurements were conducted on the first storey of a medium size, three-storey, naturally ventilated office building. In this building, due to extensive renovations, a variety of formaldehyde containing materials were used. In the first data set, just after the end of work, values of up to 0.4 ppm were recorded. Higher concentrations were encountered in the internal rooms. In the second data set, nearly one month later, formaldehyde concentrations did not exceed 0.2 ppm.

In some ventilation and dust removing system of workshop, a great deal of energy is wasted due to heated and cooled indoor air being exhausted directly. So if the dust in the indoor air is removed and then recirculate, the objective of energy saving can be reached. In this paper, the calculation equation of dust concentration, relative humidity in indoor and recirculate air and heater capacity are given along with the control measures to them.

Thermal performance of the floor-supply displacement ventilation system was evaluated in a large climatic chamber designed to simulate a single span of an office building. Detailed measurements were conducted to determine the indoor environment and skin temperature of a thermal manikin Temperature gradient in the room could be kept smaller, compared to conventional wall-supply unit displacement ventilation system, owing to the floor cooling effect of the floor-supply system.

In a room with a raised floor HV AC system (RF system), the vertical temperature gradient became an important factor in relation to the ventilation requ1rement to maintain a vertical temperature difference within a comfort standard such as ASHRAE Standard 55-1992. A series of detailed laboratory experiments were carried out to obtain the design ventilation requirements with various conditions of ventilation rates, cooling loads, and types of floor outlets. The main results are shown as follows.