Clean air passing through the ground heat exchanger uses the energy of the ground reducing expenditures for additional heating and cooling of the air, despite the assurance of forced mechanical ventilation providing fresh air from the outside .
Hewa safi kupitia exchanger joto ardhi matumizi ya nishati ya ardhi kupunguza matumizi ya ziada na inapokanzwa baridi ya hewa, licha ya uhakika wa uingizaji hewa kulazimishwa mitambo kutoa hewa safi kutoka nje .