![\""How\"](\""https:\/\/images.immediate.co.uk\/production\/volatile\/sites\/4\/2022\/01\/HeatPump-89769db.jpg?quality=90&resize=620%2C495"\" "\\"\"How\\"\/")
<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>\n1. Subterranean heat<\/h3>\n
Sunlight<\/a> warms the ground and this heat percolates down through the subsoil. The process is slow enough that the daily and seasonal weather fluctuations are evened out. Even in winter, the temperature is a constant 10\u00b0C two metres below the surface.<\/p>\n Water and antifreeze are pumped through underground pipes in a closed loop to the heat exchanger located in the house. The water is warmed up along the way by the enormous reservoir of stored heat in the ground.<\/p>\n The heat exchanger uses the warm water to evaporate a more volatile fluid \u2013 usually the same fluid that\u2019s used as fridge coolant. The evaporated vapour is then compressed using an electric pump to raise its temperature high enough to heat the water in the property\u2019s inner heating loop.<\/p>\n The pumping and compressing uses less than a third as much electricity as heating the water directly because most of the energy comes from the ground heat. The inner loop runs at a lower temperature than gas central heating though, so it\u2019s best used with underfloor heating or larger, low-temperature radiators.<\/p>\n Read more:<\/strong><\/p>\n To submit your questions email us at questions@sciencefocus.com (don\u2019t forget to include your name and location)<\/em><\/p>\n2. Absorb the heat<\/h3>\n
3. Transfer and circulate the heat<\/h3>\n
4. Reduce energy use and stay warm<\/h3>\n