How does increasing the temperature of water in a pool affect the required BTU's?

Increasing the temperature of the water in a pool requires more BTUs (British Thermal Units) to maintain that temperature. This is because as the water temperature rises, the heat loss to the environment also increases. There are several mechanisms through which heat is lost, including evaporation, convection, and conduction. Warmer water tends to evaporate more quickly, leading to increased heat loss as latent heat is absorbed during the phase change from liquid to gas.

To counteract this heat loss and keep the pool at the desired temperature, the heating system must work harder, which translates into requiring more BTUs. Additionally, the relationship between temperature and energy usage is generally linear; as you increase the temperature, the energy cost to maintain that temperature increments correspondingly. Therefore, maintaining a higher temperature in a pool directly correlates with an increase in the required BTUs for heating.