The governing parameters for flows generated by heat transfer from solar cell modules to air gaps are discussed. Experimental results are presented from measurements in mock-ups of ventilated facades and roofs. The heat transmitted from the solar cells to the air have been mimicked by the use of heating foils. The inclination angle of the roof, position of solar cell module and the height to width ratio (aspect ratio) have been varied. The bulk properties as the air flow rate in the air gap, local temperatures and velocities have been measured.
This paper describes the fluid mechanics of natural ventilation by the combined effects of buoyancy and wind. Attention is restricted to transient draining flows in a space containing buoyant fluid when the wind and buoyancy forces reinforce one another. The flows have been studied theoretically and the results compared with small-scale laboratory experiments. Connections between the enclosure and the surrounding fluid are with high-level and low-level openings on both windward and leeward faces.
A new method for compensating the space discretization error introduced when the fixed flow field is considered for the dynamic models of temperature distribution is presented. It is proved that the method generally used in literature is a particular solution of the proposed one. Moreover, it results in a continuous-time model, for which the integrating method becomes a free choice and a state-space representation is possible.
The overall thermal transfer value ( OTTV) concept has been extended to correlate the OTTV of building envelope designs with other key building design parameters through DOE-2 computer simulations. A survey of 146 commercial buildings completed between 1975 and 1995 provides the information on the prevailing architectural designs and construction practices in Hong Kong. This information forms a basis for the development of a generic office building used in the computer analysis.
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