Convective Heat Transfer in Buildings: Recent Research Results

Recent experimental and numerical studies of convective heat transfer in buildings are described and important results are presented. The experimental work has been performed on small-scale water filled enclosures: the numerical analysis results have been produced by a computer program based on a finite-difference scheme. The convective processes investigated in this research are (1) natural convective heat transfer between room surfaces and the adjacent air, (2) natural convective heat transfer between adjacent rooms through a doorway or other openings, and (3) forced convection between the building and its external environment (such as, wind-driven ventilation through windows, doors, or other openings).

Results obtained at Lawrence Berkeley Laboratory (LBL) for surface convection coefficients are compare with existing ASHRAE correlations and differences of as much as 20% are observed. It is shown that such differences can have a significant impact on the accuracy of building energy analysis computer simulations. Interzone coupling correlations obtained from experimental work reported are in reasonable agreement with recently published experimental results and with earlier published work. Numerical simulations of wind-driven natural ventilation are presented. They exhibit good qualitative agreement with published wind-tunnel data. Finally, future research needs are suggested.