I am building a new house near Albany, NY which is region 5A. I plan to have a super-insulated house with an Ultimate Air ERV. I would like to hook up a ground loop system to the ERV which would consist of tubing that is looped around the foundation footing a couple of times which would contain water or an anti-freeze mixture. The liquid would be pumped through a water to air heat exchanger on the intake side of the ERV in order to raise the input air temperature during the heating season. Where can I find design details for a system like this? What kind of tubing should be used? Is an anti-freeze mixture needed?