I sent an email out to Jeff Gagnon and Jim Godbout and asked them five basic questions about ground source heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump. installations. In this part of the Green Architects' Lounge episode, Phil and I take some time to review and compare their answers. We also touch on the subject of ozone depleting refrigerants. Then, Phil shares a song by the Brooklyn band 'Here We Go Magic' called collectors.