Is there a way to model air source to water heat pumps in the plant with equest? These are quite common on the West Coast in Canada. AirStack is a typical brand. >> Christopher Jones, P.Eng. Suite 1801, 1 Yonge Street Toronto, ON M5E1W7 Tel. 416-203-7465 Fax. 416-946-1005 email cj at enersave.ca