Most of it is dispersed as heat, but the remainder is held in concrete and buildings and then is radiated back to the air at night. Trees, with the right vegetation, can block up to 95 percent of the incoming radiation. Trees will intercept up to 90 percent of summer solar energy and provide large reductions in interior temperatures. Trees and shrubs planted next to a home can reduce summer air-conditioning costs by 40 percent. Proper arrangement of vegetation around buildings can also substantially reduce home heating costs.
Plants can reduce infiltration by slowing the rate of the wind.
On cold, windy days, infiltration can cause as much as a 50 percent heat loss from a building. Planting layers of vegetation close to and on exterior walls will trap air, which has an insulating effect on the exterior surface. Proper placement of plants can enhance the flow of solar radiation through windows in the winter for added warmth.