Building energy reductions - windbreak optimization.

Uses wind tunnel model studies of houses to determine how best to reduce the surface pressure variations from wind and the associated air infiltration emphasizing the correct placement of suitably modelled coniferous trees. Finds that tree crowns convert the directed kinetic energy of approaching wind into random turbulent energy, which reduces pressure gradients on the windward walls, a prime region for air infiltration. The most cost and energy effective windbreaks are those that selectively protect against prevailing winter winds,use as few trees as possible, and are placed at least 2 tree heights upstream. Using an optimum planting pattern, an estimated 10% savings in energy for heating can be achieved.