An average full size deciduous tree evaporates 100 gallons of water during a sunny summer day, which uses up about 660,000 British thermal units (BTUs) of energy and cools outside a home as well as five average (10,000 BTU) air conditioners.
“Energy Efficient and Environmental Landscaping” by Ann Simon Moffat, Mark Schiller, and the staff of Green Living, p. 9