We installed a closed loop system as part of our student projects in our lab at Oakland Community College. In addition to Brad’s comments:
If your house is already under built, it is more expensive to install;
You should put money first into energy conservation and weatherization for the best environmental and economic impacts;
Heat pumps use electricity which, if produced from coal, is less efficient than direct combustion of natural gas or propane contributes more to climate change and air pollution than natural gas per unit burned, although you do have to calculate the cop of the equipment to get the exact outputs. The EPA has an online greenhouse gas calculator you can use;
Closed loop systems do not use up water, they reuse the same systems again and again; Open loop systems use water, the amount depending on the heating and cooling load in the home;
If you were building the home from scratch, using low cost and no cost sustainable design techniques would get your heating and cooling loads to such small numbers that a ground coupled heat pump system wouldn’t make sense. In Michigan, you should easily be able to build a home that has heat bills under $250 per year of natural gas. See the Renewable Energies Booklet and other energy information at www.urbanoptions.org for more info. You can substantially reduce your bills in existing homes too.
For more info on energy efficient/sustainable design in an online course format, go to www.oaklandcc.edu/EST and look at the AET 2010 course for a Michigan course or to Solar Energy International.
Hope this helps,
Debra Rowe, Ph.D.
Environmental Systems Technology
We need to replace our current furnace system by winter and are looking into the possibility of a Geothermal system.
I am wondering if anyone has one, and if they are as great as they sound. Any environmental impacts?
How about energy conservation? Also, I wonder about the amount of water they use and if they create an impact of aquifer levels, et.
Any info or opinions would be greatly appreciated.
Traverse Group of the Sierra Club
PIONEERS OF A WARLESS WORLD ARE THE YOUTH WHO REFUSE MILITARY SERVICE."