It is almost impossible to say precisely how long it will take to heat a pool. Why? Primarily thanks to the fact that the weather and the pool’s ambient temperature always affect the heating time.
In this post, Dolphin Pool Service discusses how most pools can take a few hours to reach a comfortable average temperature with the right combination of factors.
Factors that Affect the Pool’s Temperature:
The size of the pool
When heating a pool, British Thermal Units, or BTUs, are used. The BTUs required to heat a specific volume of water are mostly determined by the pool size. To achieve the same temperature, larger pools would require more BTUs than smaller pools.
A 10 x 30 ft. rectangular pool requires between 3,600 and 7,200 BTUs of energy per hour to keep the water at a comfortable 80° F, according to Consumer Reports. That’s a really little pool. To provide the same degree of comfort, a bigger pool (say, 40 x 18 ft.) requires between 8,400 and 14,100 BTUs.
The pool’s water level
How does the water level influence the time estimate? Heat will not reach the deepest regions of the pool if the water level is too low.
Warmer air holds more moisture than cooler air above the pool. As a result, keeping the pool’s water level steady will keep the water from chilling too rapidly during colder weather.
The shape of the pool
The surface area of the water is also affected by the design of the pool.
It takes longer for a deeper pool to warm up.
Because of the larger surface area, round pools take longer to warm up than rectangular pools.
Local Weather
The weather is another aspect that might influence the temperature of your pool. During the summer, the pump’s temperature will not need to be as high. The pool may not even lose all of its heat during the warmer evenings, depending on your location.
Winter is a whole other story. To keep the water temperature acceptable for more than twenty-four hours, the pool heating source will need to be carefully adjusted. Weather factors, such as rain or cloud cover, may also affect the pool’s ambient temperature, requiring you to regulate the heating system accordingly.