The heat pump is by far the most efficient thermal machine of any heat generator available on the market. Therefore applications that involve the use of heat pumps are increasing, thanks to the reduction of emissions of carbon dioxide (CO2), the possible use of electricity (available everywhere) and renewable energy; not least is the advantage of being able to remove the flues and heating plants, fuel tanks or connections to the gas network. The strength, however, is the lack of environmental pollution and, if you have electricity produced by the PV system, even you get a system with zero environmental impact .