Which factor is NOT typically a consideration when determining pool heater size?

When determining the appropriate size for a pool heater, several crucial factors come into play to ensure optimal heating performance. The size of the swimming pool is paramount, as it directly influences the volume of water that needs to be heated. The larger the pool, the more energy and capacity the heater must have to effectively raise the water temperature to a desired level.

The desired water temperature is another key consideration. Different pools have different temperature requirements based on usage—such as recreational swimming, therapy, or competitive swimming—so this affects the heating requirements and overall capacity needed from the heater.

Ambient air temperature is also significant. It affects the efficiency of the heating process. The colder the surrounding air, the more energy is required to maintain the desired water temperature, as heat loss to the environment can be considerable.

In contrast, the material of the pool deck does not have a direct impact on the heat capacity or efficiency of the pool heater. While certain materials may affect heat retention or contribute to comfort for pool users, they do not play a critical role in determining the size of the heater required to warm the water. Thus, when identifying essential factors for heater sizing, the pool deck material is not typically considered.