How To Size A Pool Heater? 3 Easy Steps!

Are you wondering about how to size a pool heater? Well, wonder no more, you come to the right place because we’re here to help you out! You can size your pool heater by estimating your pool size and then calculating the area where you want to put your pool.

When you precisely size a heater, your pool water should achieve the optimum temperature in the timeframe you specify. 

how to size a pool heater

An excessively small pool heater will heat the pool very sluggishly, and an overly large pool heater will unduly increase the expense of this large purchase. The general rule is that bigger is better, but only up to a point for heaters. A pool heater having 400k BTU heats a pool twice as efficiently as a heater having 200k BTU & consumes propane nearly two times as quickly as a 200k BTU heater compared to a pool/spa combo; a pool takes less BTU electricity to heat. Below we’ll discuss how you can size a pool heater. Let’s get started!


Steps To Size A Pool Heater

Sizing a pool heater is not an easy task, but you can do it quickly if you understand how to size a pool heater. Below we have discussed all the steps that help you size your pool heater correctly. 


Step #1. Calculate Your ideal temperature

When you size your pool heater, you must first calculate the temperature you want for your pool heater. Most heaters have a perfect spot at 82°F and 86°F; therefore, we’ll choose 85°F for convenience. After that, determine what your local average air temperature is. We’ll select 73°F for this case. Minus this temp from your target of 85 degrees Fahrenheit. 12°F = 85°F − 73°F Now divide 12°F by 8, and that is the number of hrs it will take to warm the pool thoroughly. 12°F divided by 8 (hours) is 1.5° each hour. To heat the pool in 8 hours, the heater must increase the temperature of the water by 1.5 degrees every hour. Know how long does a pool heater last.


Step #2. Estimate your surface area

Calculating the surface area of your pool is the first step in selecting which size pool heater is perfect for purchasing. Many pool users believe you should size your heater based on the gallon capacity of your pool. In reality, the quantity of gallons is used on several internet sites. When you possess an enormous surface area pool, the warm air has much more room to exit, and, as a result, there is much more water to heat. As a result, the heater must be big adequate to account for the pool’s size and coverage area. Multiply the length by the width to measure the surface area for your pool. As an illustration: A 15 x 30 pool has a surface size of 450 sq ft.


Step #3. Divide 3 times the area of the pool’s surface

After estimating your surface area, the next step is to determine the BTUs for your pool heater. The pool’s surface area multiplied by three is the minimum BTU size advised for that large specific surface coverage. Using the 15 x 30 pool as an example, you gain 150 when dividing by three. As a result, for a 15 x 30 pool, a minimum heater capacity of 150,000 BTUs is advised. Simply this is the smallest size that is suggested. I’m continually pushing myself to new levels. You should always oversize your heater, especially regarding gas warmers. A pool heater’s function is to replace heat lost via evaporation at the pool’s surface. Up overnight, the majority of heat is lost. It is impossible to compensate for the loss without a sun cover. 


Consider Few Things While Sizing Your Pool Heater

When choosing the size of your heater, keep the following in mind:


#1. The element of convenience

In the pool heater, primarily natural gas is used, which is piped through a pipeline and may be stored indefinitely in an enlarged tank; however, propane must be stored in a large tank. Refilling this container may be a technical headache because it weighs hundreds of thousands of pounds while loaded; supplying this container may be a technical headache.


#2. The rate of heating the water

Would you like to be able to light up your pool in a matter of hours? Do you wish to go swimming on a routine basis during the winter? If this describes you, a big BTU propane furnace will warm quickly and won’t require extended periods of operation. Propane outperforms natural gas in this application because it flames higher and warms up quickly. Find out how does a pool heater works


#3. Your gas line’s diameter

When sizing your pool heater, you’ll also need the correct gas line length and diameter. If you already run gas through a ¾” pipe to a 150,000 BTU heater, which is 20 feet long,  an updated 400,000 BTU heater would necessitate a bigger 1¼” gas pipeline that also transmits the gas at the length of 20 ft. Read more about pool heater sizing.


It’s  A Wrap!

We hope that after reading this article it is just fun for you and after reading it you all will understand how to size a pool heater. Above, we have discussed three easy steps while sizing a pool heater and a few things that you have to bear in mind y=while sizing a pool heater. Thank you, friends, for being with us at the end!

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