One of popular swimming pool accessories used by pool owners is a pool heat pump. This helps them to use the pool even in very cold weather when the water is too cold to swim in. A heat pump functions in a very simple manner, just like your air conditioner, refrigerator, water cooler, or dehumidifier does, but in reverse. https://www.aircalheatpump.com/product/all-in-one-heat-pump-water-heater
