Pool heaters are a great investment for any swimming pool because heaters can extend your swimming season. This means you can get the most out of your swimming pool and we would all love to do that. However before you go out looking for pool heaters, it would be wise to educate yourself before diving right in.
Pool heaters come in all sizes and styles and it’s best to know what you will be dealing with. When shopping for a heater make sure you know how many gallons or how big your swimming pool is. This all depends on the BTUs (British Thermal Unit) your heater will be. Heater sizes are measured in the amount of BTUs it puts out.
The chart below tells you how many BTUs it would take to heat your pool by how many degrees:
| Increase In Temp. | Increase In Temp. | Increase In Temp. | Increase In Temp. | Increase In Temp. | |||
| Pool Length (Ft) |
Pool Width (Ft) |
Sq Ft | 20 | 25 | 30 | 35 | 40 |
| 15 | 30 | 450 | 108,000 | 135,000 | 162,000 | 189,000 | 216,000 |
| 16 | 32 | 512 | 122,880 | 153,600 | 184,320 | 215,040 | 245,760 |
| 16 | 36 | 576 | 138,240 | 172,800 | 207,360 | 241,920 | 276,480 |
| 18 | 36 | 648 | 155,520 | 194,400 | 233,280 | 272,160 | 311,040 |
| 18 | 40 | 720 | 172,800 | 216,000 | 259,200 | 302,400 | 345,600 |
| 20 | 40 | 800 | 192,000 | 240,000 | 288,000 | 336,000 | 384,000 |
| 25 | 45 | 1125 | 270,000 | 337,500 | 405,000 | 472,500 | 540,000 |
| 30 | 50 | 1500 | 360,000 | 450,000 | 540,000 | 630,000 | 720,000 |
| 30 | 60 | 1800 | 432,000 | 540,0 | 648,000 | 756,000 | 864,000 |
This next chart is a simple way to figure out what size swimming pool heater you will need for your pool:
| Pool Gallons | Heater Size |
| 1,000 to 10,000 | 100-200 BTU |
| 10,000 to 20,000 | 200-300 BTU |
| 20,000 to 40,000 | 300-400 BTU |
| 40,000 to 80,000 | 400 BTU |
Types of Heaters
Generally there are 3 types of pool heaters, they include:
1. Propane
2. Natural Gas
3. Electric Heat Pump
Gas Pool Heaters
When looking for a typical pool heater you will want to look at Propane and Natural Gas. These types are the most common pool heaters and the good thing is there is no price difference. It depends on what your needs are. If your home doesn’t already have a natural gas hook up you will need to go with propane. This means the propane company will have to install a propane tank in your yard unless you already have one. If you go with natural gas then the gas company would have to come out and run a line to your pool heater. Gas pool heaters for inground pools start out at around $1,000.
Gas Pool heaters come in different BTU sizes including:
100,000 BTUs
200,000 BTUs
300,000 BTUs
400,000 BTUs
Electric Heat Pumps
If you are looking to save money in the long run and don’t mind a hefty up front cost then heat pumps are the way to go. Heat pumps work by capturing the air outside with a fan and turning it into warm air to heat the water that passes through the pump. These come in lower BTUs and cost quite a bit, but over time you will save money because you won’t be using gas to heat your pool. Heat pumps for inground pools start out at around $3,000.
Electric Heat Pumps come in different BTU Sizes including:
100,000 BTUs and 125,000 BTUs
