Air energy, or low-grade thermal energy contained in the air, also known as an air source. The law of conservation of energy tells us that energy cannot be created or destroyed. However, according to the laws of thermodynamics, heat cannot be transferred from a low-temperature object to a high-temperature object without causing other changes. While air energy is limitless, to transfer the absorbed energy from the air to a high-temperature environment, electrical or thermal energy must be consumed, a technology known as an air-source heat pump.