You don’t have to build something new to take advantage of green building design. Old is just as good as new when it comes to renewable energy programs to cut heating and air conditioning bills.

Take, for example, Boston’s historic landmark, Trinity Church.

It’s relying on a geothermal heat pump system for all of its heating and cooling in church meeting rooms and the church store. And, the church is cutting its carbon footprint by reducing demand for coal-fired electricity that creates greenhouse gas (GHG) emissions.

When the church renovated its facilities a couple of years ago, it couldn’t add modern new HVAC equipment on its historic roof. That just wouldn’t look right or fly with the historical preservation crowd that wants to keep the church looking just like it did when it opened in 1877. So it went the only place it could, underground.

The geothermal system pumps water 1,500 feet underground to take advantage of the constant 55 degree temperatures there. Heat exchangers then transfer the energy from the geothermal wells to heat and cool some of the church and its related facilities. (Alas, the church itself isn’t air conditioned, so it maintains a 19th century feeling all summer long.)

There’s a bottom line plus: Relying on renewable, geothermal power cuts related heating/cooling bills. The International Ground Source Heat Pump Association says geothermal heating is 50% to 70% more efficient than standard systems. Cooling with geothermal is 20% to 40% more efficient.

There’s also stimulus money available for investing in geothermal. The Geothermal Heat Pump Consortium explains how homeowners can obtain a 30% tax credit for such investments. Click here for details.

Tags: geothermal, heat pumps, renewable energy, Trinity Church