A Guide to Pool Heaters

Economy Pool Blog

Choosing the right heater unit for your pool is an important decision; making the correct choice could save you thousands of dollars over the long term life of your pool. The two main factors to consider are the type and size of pool heater you need. Deciding what type of heater you prefer should be your first choice, as the different units require different sizing criteria.

There are three main types of pool heaters, and each has its pros and cons.

Gas Pool Heaters

This is the cheapest up-front option, with most being tied directly into natural gas through the utility company. In areas where natural gas isn’t an option, propane and oil models are available. The best feature of gas pool heaters is they can maintain even water temperature even in extreme weather fluctuations. The downside is they will use quite a lot of fuel to do so, but newer models that use pilotless ignition are up to 90 percent more efficient.

Gas heaters work by passing pool water directly through a burning hot tube and returning it to the pool. Depending on the size and temperature of your pool, homeowners can expect to pay between $300 and $600 a month to heat a pool using natural gas, and slightly more for propane. The newer, more efficient models cost between $1,500 and $3,000 to install.

Pool Heat Pumps

Pool Heaters operate through a system of coils and utilize condensation and evaporation within the unit to remove warmth from the surrounding air to heat pool water. While they do require electricity, they don’t produce emissions and are cheaper to run annually than their gas counterparts, averaging at most about $1,400 a year in more tropical climates. They also have a much longer lifespan.

The downside, however, is that you’ll pay quite a lot more up front. Heat pumps start around $2,000 and can go as high as $5,000 for more efficient models. Further, they don’t do as well in colder climates where the temperature drops below 50 degrees.

Solar Pool Heaters

Solar heaters, while more expensive to install, are gaining popularity due to their long term energy efficiency. They work by sending pool water through a series of metal pipes attached to solar panels. If sensors indicate warmth is needed, the valve sends water through the system. If the water is warm enough, the system is bypassed. Solar systems can be attached to conventional gas heaters if additional heat is needed.

A solar pool heater will cost about $4,000 to install, but is essentially free to operate after. Your yard will require direct sunlight year round, or you’ll be required to have a back-up unit. The major downside to a solar pool heater is that it heats the water very slowly, making them a better choice for climates that stay warmer most of the year.

Pool Heater Sizing

There are quite a few factors to consider when sizing your pool heater. Besides the surface area and size of your pool, average air temperature, humidity, winds and your desired water temperature all play a part. Gas and pump heaters are measured in BTUs (British Thermal Units). When choosing your heater, once you’ve factored in all your components, it’s best to size up slightly from what you think you’ll need.

The generally accepted formula for figuring out the BTUs needed per hour is to calculate the surface of the pool area x the temperature rise (your desired pool temperature minus the coldest average temperature and multiply this number by 12.

Solar heaters are sized in direct relation to the surface area of the pool. Your solar collector needs to be 70 to 100 percent of your surface area, depending on the sun exposure your climate receives.

The easiest way to determine what the best option and size of pool heater is for your pool is to contact the installation professionals at Economy Pool of Florida and let them walk you through the process. They will discuss the pros and cons of each model for your setup, and help you appropriately size whatever you choose to keep your pool the right temperature all year long.