Air Sourced Heat Pumps do not have a flat plate or evacuated tube collector instead drawing their heat from the sourrounding air. Heat pumps generally return three units of energy for every unit they consume and are well suited to Australian conditions. Heat pumps work by pushing air through a finned coil evaporator and fan, the extracted heat is being used to heat the water (like an air conditioner). Heat pumps are not as efficient as solar boosted units but perform well as ambient temperatures increase and have lower installation costs.