How to Choose a Pool Heater: Gas Heater, Heat Pump or Solar Heater?

During cold seasons like winters, swimming pools are always ice cold and most of them go under winterization, which means they are closed for the whole periods of the winter and fall.

However, People who like swimming and warm baths do not like Winterization, people want to enjoy swimming in any season anytime as they want. With pool heaters, People can enjoy your winters and any cold weather days in a spa without worrying about ice cold water.

There are 3 main types of spa heaters; gas heaters, heat pumps, and solar heaters. Before choosing, you have to know the working principle and be sure it is the best  option in terms of size, how convenient the heater is and the cost factor.

A). Gas Heaters
Gas heaters are the most common pool heaters you will find around. I suppose, this is because gas heaters are instant and very convenient when you need your pool or spa ready within a short time.

A standard pool gas heater will heat spa water to desired temperature within 15 minutes as compared to a heat pump that takes up to 45 minutes and solar heater even longer.

Moreover, a gas heater heats your water in all kinds of weather; hot, cold or rainy, which is not possible with solar heating system that may opt you to winterize your pool during the winters.

Gas heaters use a natural gas or Propane to create fire in a heat coil exchanger, which heats water on its way to the pool.

Modern gas heaters like Hayward Universal H Series are made to be regulated between low, medium and high BTU (British Thermal Unit) or temperatures that suit the user.

When selecting a gas heater, you have to be very keen on the size of the heater in BTU: If you want to heat water in a big pool or spa, you need larger BTU Gas Heaters, the larger your pool is, the more you need a gas heater with larger BTU.

Also, it is important to know that you can use a bigger BTU gas heater in a smaller spa to increase efficiency. Most gas heaters in the market today range between 100,000 BTU and 500,000 BTU and you go with the best size for your pool.

Lager pools from 20,000 gallons can use between 300,000 BTU and 500,00 BTU gas heaters for faster and instant heating. But it won't hurt to use 400,000 BTU gas heater on a 10,000 gallons pool, in fact it will be more efficient, instant, and with low operating cost.
Like said earlier, smaller BTU natural gas pool heaters do not heat larger pool water faster and are best only if you have or want to put up a small hot tub and maintain hot water all the time like during the winter seasons or cold days.

Cons of Gas Heaters
Gas heaters are made of different heat exchanger materials; Copper, Cupro-Nickel, and ASME Copper. Copper heat exchanger, which is the most common and affordable gas heat exchanger, is made of copper coils, and therefore prone to causing green copper stains in spas when chlorine is added or rises above normal level and when pH level is low in pool water.

Cupro-Nickel and Copper ASME are upgraded pool heaters and have higher resistance to chemical damage compared to pure copper heat exchanger.
Copper, Cupro-Nickel, or ASME Copper: Which is the Best Heat Echanger Material?

Gas heaters come in 3 different heat exchanger materials as follows:
1. COPPER HEAT EXCHANGER
Copper heat exchanger is the most common heat exchanger material and is suitable for use in any pool or spa that is chemically balanced and well maintained.

However, Copper heat exchangers have low chemical damage resistance and will be oxidized easily to cause metal stains if used over a long time without treating or removing copper metals that accumulate in your pool water.

Copper metal stain is green in colour and is formed when chlorine is added in spa water or when pH level goes down.

Due to low chemical damage resistance, Copper heat exchangers are not suitable for salt-water pools: Saltwater pools are know to have high calcium level issues and may cause calcium scales on copper heat exchanger reducing its efficiency.

How to Prevent Copper Stains When Using Copper Heat Exchanger
To use a copper gas heater without having metal stains issues, you need to measure copper metal levels in your water at least every month and reduce copper levels when high by draining and refilling a given portion of your spa water with fresh water.

Alternatively, if draining and refilling your spa water is expensive, you can add a metal remover like ProTeam Metal Magic to remove copper metal through the filter, then backwash and rinse your filter to clean it.

You can also use Clorox D.E. Media + Filter Aid in your skimmer to filter out copper metals before entering your pool and prevent metal stains when chlorine is added or pH is low;

2. CUPRO-NICKEL HEAT EXCHANGER
Cupro-Nickel Gas Heater comes with heat exchangers made of cupro-nickel, which has a very high resistance to corrosion and staining caused by high chlorine or low pH and saltwater.

Cupro-Nickel gas heater will cost a little extra dollars as compared to the base copper heater, but with great functionalities worth your money.

Cupro-nickel gas heater are highly recommended for saltwater pools due to their high resistance to chemicals and saltwater damages.

B). Heat Pumps
Heat pump is the second swimming pool heater we are going to look in to due it's efficiency in heating and maintaining required water temperature in a hot tub or spa.
Depending on the size of the heat pump, you need to choose the best size heat pump that will heat your small, medium and large spa water faster.

Heat pump uses electricity and that is why it's effective in heating and maintaining your spa water temperature at a cost that can be slightly lower than other types of pool heaters.

Although slower in heating rate compared to natural gas heater, heat pumps are considered cost effective and handy when you need to maintain hot water in your spa for a long period since it does not use a lot of power to maintain water temperature.

One big advantage of top brand heat pumps like Leomon Pool Heater is that you can regulate the water temperature levels up and down to suit the users preference, and therefore apart from heating your water, it can be used as a chiller to reduce water temperature in areas that have hot and humid temperature and spa water temperatures tend to rise often.

Before you buy a heat pump, you need to know the water temperatures that you will maintain first in your spa, then select the right size heat pump that will heat and maintain your water temperature efficiently.

Just like gas heaters, heat pumps with larger heating capacities are the best for larger pools and are fast heaters.

To select the right heat pump for your spa, use this formula recommended by US  Department of Energy to select the right size heat pump in BTU:-
Pool Area x Temperature Rise x 12.

Cons of Heat Pumps:
Heat pumps are not instant pool heaters and are not recommended when you need instant pool warming especially in colder regions.
Heat pumps are useful; and economic to maintain a given water temperature in smaller spas and in less colder regions where less electric energy will be used.

C). Solar Pool Heaters
Swimming pool solar heater system works by heating water that is run through small pipes in the panel, which are good heat conductors and are warmed by the Sun.

Solar heaters are only useful during the summer and only during day light when there is Sun, and cannot be used during winters and cold days.

Installing solar heater might be expensive compared to gas and heat pump, however, it has the minimal operating cost since it uses the Sun as the source of power, which is absolutely free.

Alternatively, you can use a spacial Solar Pool Cover to warm your water during sunny days or during the summer. These pool covers are made to heat your pool water using heat from the Sun and retain a warm temperature longer in your water by preventing evaporation both in the night and chilly days.

Cons of Solar Pool Heating System
The main disadvantage of solar heaters or solar pool covers is that they are only useful when there is Sun and during the Summer. Solar heaters or pool covers cannot be used during the Winter or when there is no Sun.