The swimming season in Canada seems like it gets shorter every year. In order to extend their swimming season, more and more pool owners in the Ottawa area turning to pool heaters. Today, we will look at the most common types of pool heaters to help you decide which pool heater is best for your pool.

Properly Sizing Your Heater For Your Pool

Before we get into the different types of pool heater, we need to get something out of the way. When it comes to pool heaters, size really does matter. If you buy a heater that is rated for a 40,000L pool and you have an 80,000L pool you’ve got a problem. It doesn’t really matter how good the heater is, if it is too small it will not efficiently heat the water in the pool, leading to sky-high energy bills.

Before you buy a new pool heater, you want to make sure that it is large enough to properly heat the water. To do this, you will need a rough estimate of the size and volume of the pool. To do this, make a rough sketch of the pool’s shape. You can then measure the pool at its widest and longest points and make note of those measurements on the sketch. For the most accurate results, you should also make note of how deep the pool is; both in the shallow and in the deep end (if the pool has a shallow and deep end that is). You can then take this sketch to your local pool retailer, who can calculate the volume of the pool for you.

Now that that is out of the way, let’s explore the different styles of pool heaters.

Gas Pool Heaters

Gas pool heaters work by igniting either natural gas or propane within a “combustion chamber” located inside the heater. This burning gas then heats a metal coil. As the pool water flows through the heater, it passes through this coil and is heated. This process continues until the pool water reaches a set temperature, at which point the heater will shut itself off. This temperature can be adjusted manually using the heater’s built-in controls.

Advantages Of Gas Pool Heaters

• Gas pool heaters heat the water very quickly. In fact, a properly sized gas heater can easily increase the water temperature in a pool by 3-4°F per hour. A pool that is 70°F in the morning can be easily heated to 80°F or higher by lunchtime!
• Built-in temperature controls. Most gas heaters also allow you to set an exact temperature for your pool water.

Disadvantages Of Gas Pool Heaters

• They can be costly to install. A good gas heater will set you back $2000 or more. They also require professional installation. While the plumbing installation usually doesn’t cost very much, the gas installation can be pricy depending on where your existing gas hookup is located.
• They can be costly to operate. The running costs of a gas heater are the highest among the three main pool heater options when looked at on a per hour basis.

Heat Pumps

Heat pumps work by drawing in warm air from the outside using a built-in fan. This warm air then passes over the heat pump’s “evaporator coil”, which is filled with a refrigerant. When the warm air combines with the refrigerant, a chemical reaction occurs which produces a warm gas. This gas then heats a metal tube. As the pool water passes through the metal tube, it is heated to the desired temperature, at which point the heater shuts off.

Advantages Of Heat Pumps

• Lower running costs than gas heaters. The per hour cost to run a heat pump is much less than that of a gas heater.
• Temperature controls. Like gas heaters, heat pumps allow you to set an exact temperature for your pool water.

Disadvantages Of Heat Pumps

• Slow to heat the water. Even a properly sized heat pump can usually at best only manage to raise the water temperature by around 1-1.5°F in an hour.
• Heat pumps are costly to purchase. Although not quite as expensive as gas heaters to install (they only require a 220V electrical service and basic plumbing installation), their high purchase cost ($3500+) means that heat pumps have the highest up-front costs of any pool heater.

Solar Pool Heaters

Solar pool heaters use energy from the Sun to heat up your pool. They are by far the simplest pool heaters available. Solar heaters are made up of one or more black plastic or rubber panels. These panels absorb solar heat. Water then passes through the warmed panels and is heated up.

Advantages Of Solar Pool Heaters

• Solar heaters are the cheapest to purchase and install. Since solar heaters do not require electrical or gas hookups, they’re much cheaper to install; often times these installations are done by the pool owner and cost less than $100 in parts. They’re also much cheaper to purchase, although the actual cost varies quite a bit depending on the size of the pool.
• Cheap to run. Although they’re not free to run (your pool pump needs to be on in order for water to pass through the heater) the costs to operate a solar pool heater are far lower than both gas heaters and heat pumps.

Disadvantages Of Solar Pool Heaters

• Solar pool heaters are inconsistent. This is because they can only effectively heat the pool water on hot, sunny days. On cold days, solar heaters can even cool the water! To combat this, most pool owners install shutoff valves in the pool plumbing so that they can bypass the solar heater on colder days.
• No temperature control. Unlike gas heaters and heat pumps, solar pool heaters don’t let you set a temperature. You get what you get.

So Which Type Of Pool Heater Is Best?

So now that you know a little more about the most common types of pool heaters, the question is which one is best? The answer depends on how you plan on using your pool. As you can see, each pool heater has its own advantages and disadvantages. To help you decide which one is best for your pool, here are a few common scenarios.

You Want To Extend Your Swimming Season

The most common reason why people in Ottawa are buying pool heaters is to extend their swimming season. If you’re interested in extending your swimming season, you will want to get either a heat pump or a gas heater. Solar heaters are simply too inconsistent and don’t work well in colder weather.

When looking to extend your swimming season the heater you should ultimately choose should depend on how often you will be using the pool. If you consistently use the pool throughout the week, get a heat pump. If you plan on using the pool less often, a gas heater will ultimately end up being the cheaper option. Why is this? It all comes down to how fast the pool heater is able to heat the water.

You Want A Warm Pool, But Only Use It On Certain Days

If you’re busy and only have the chance to use your pool here and there, a gas heater is likely your best choice. Gas heaters are able to heat the water so quickly, you are able to get the pool water up to your desired temperature within a matter of a few hours, perfect for spontaneous swims!

Although they are more costly to run per hour when compared to a heat pump, since you will only be running the heater for a few hours each week, in this scenario a gas heater will also be less expensive to run than a heat pump. This is because a heat pump typically needs at least 24 hours to properly heat a pool, where the gas heater will only need 2-4 hours.

You Want To Keep Your Pool At A Consistent Temperature

If, on the other hand, your family use your pool consistently throughout the summer and want to make sure that it stays at a consistent temperature, a heat pump is your best choice. Heat pumps are perfect in this scenario as they are able to maintain your desired temperature and are significantly less expensive to run than gas heaters on an hour by hour basis.

You Only Swim When It Is Sunny

If your family is the type that only wants to swim on hot, sunny days, solar heaters are probably the best option for you. Since they are inexpensive to purchase and run, you won’t be overpaying to heat your pool.