Gas companies charge by the cubic meter (2.77 m3) (which is equivalent to 100,000 BTUs); therefore, knowing it will take 9.8 hours to raise the pool water temperature, the cost can be calculated by multiplying the heat up time (hours) by the heater’s BTU input, then dividing by 100,000 and multiplying by the cost per cubic meter.
9.8 x 400,000 = 3,920,000 (total BTUs)
3,920,000 / 100,000 = 108.8 m3 used
Using the Ontario Energy Board’s online bill calculator, if the cost of gas is 17.9 cents/cubic meter (factoring in customer, delivery, supply charges, and taxes), the approximate cost would be $61.45.
(or $61.45 to raise the water temperature in a 75,708-L [20,000-gal] pool by 20 degrees in 9.8 hours)
Using a five- to seven-year-old 400,000 BTU heater that was rated 78 per cent efficient, but is now only operating at 65 per cent, the heater output would only be 260,000 BTUs.
3,332,000 BTUs required / 260,000 = 12.8 hours
12.8 x 400,000 = 5,120,000 BTUs
5,120,000 BTUs / 100,000 = 142.1 m3 used
Again, using the Ontario Energy Board’s online bill calculator, if the cost of gas is 17.9 cents/cubic meter (factoring in customer, delivery, supply charges, and taxes), the approximate cost would be $75.59.
This means it would cost the aquatic facility 23 per cent more to heat the same body of water using an older heater.
| Five reasons to install a new heater |
|---|
| 1. Lower energy costs as they have much higher efficiencies (between 85 and 96 per cent) than older models (between 60 and 78 per cent). |
| 2. Smaller and take up less space. |
| 3. Lower emissions, making them better for the environment. |
| 4. Much easier to maintain (plug-and-play). |
| 5. Quiet operation, reducing noise levels at commercial aquatic facilities. |
Choosing a heater for a commercial pool
To select the appropriate heater for a commercial pool, its size and location (indoor or outdoor) must be considered. To calculate the approximate heater size for a pool, facility managers need to:
- Determine the desired pool water temperature (the average is [27.7 C] 82 F for competitive swimming);
- Determine the average temperature for the coldest month of pool use (for outdoor facilities);
- Subtract the average temperature for the coldest month from the desired pool temperature. This will give the temperature rise needed;
- Calculate the pool surface area in square metres (square feet); and
- Determine the BTU/hour output required using the following formula: pool area x temperature rise x 12 = the BTU/ hour output required.
To clarify, heaters are sized based on a 24-hour temperature rise. So, a heater with a one million BTU takes 24 hours to raise the pool water temperature 15 degrees. Based on this information, a facility manager can determine which heater is appropriate for the commercial pool he/she operates.
