
Portland, Maine’s new airport expansion is to be the first in the country to use a dead-simple but often overlooked technology to significantly reduce its heating and cooling bills. They’re calling it a geothermal system, but it’s not like the kind that produce power in Iceland; it’s more properly called a “ground-source heat pump.” With a $2.5 million VALE grant, the innovative, geothermal heating and cooling system that will save the 137,000 square foot...







