Guest Column - November 2012
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Beat the Heater
Upgrading Aquatic Facility Heaters to Reduce Costs

By Mike Fowler

Choosing a Heater

If you are now faced with a heater that is not operating efficiently and has caused your energy consumption to increase drastically for a reduced output, how do you choose a new heater?

It is important to realize that pool size does matter—as do factors such as whether or not the pool is an indoor or outdoor pool.

To calculate an approximate heater size for a pool:

  1. Determine the desired swimming pool temperature (average is 82 degrees for competitive swimming).
  2. Determine the average temperature for the coldest month of pool use (if the pool is an outdoor pool).
  3. Subtract the average temperature for the coldest month from the desired pool temperature. This will give the temperature rise needed.
  4. Calculate the pool surface area in square feet.
  5. Use the following formula provided by the U.S. Department of Energy:

    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 1 million BTU takes 24 hours to raise the pool temperature 15 degrees.

Additional Benefits

Here are a few additional reasons to upgrade to a new heater:

  • Lower Emissions: Now there are cleaner burning heaters or Low NOx heaters, which have minimal emissions. In most of California, as well as Texas, these are required and have a regulated emission standard. Other states are sure to follow in the coming years.
  • Easier Maintenance: Today's commercial pool heaters face changing conditions as many installers have not been trained in commercial application techniques. Plus, facilities find that pool cleaning staff, lifeguards and facility managers are all adjusting heater settings frequently. So, having a unit that is completely enclosed and ready to go leaves less room for problems caused by facility staff.
  • Sealed Combustion: Many new heaters today have sealed combustion units. These are safer because: Pool heaters installed indoors are frequently located next to stored chemicals—so if they are sealed they are less of a fire hazard (even if chemicals are not present when heater is installed, chemicals maybe present later; and adequate combustion air is guaranteed when outside air is ducted with a sealed combustion unit.

Now you have all the facts for considering an upgrade to a newer, more efficient heater that will immediately reduce your energy bills and monthly operating costs. A new heater upgrade will surely lower an aquatic facility's monthly operating costs, will operate and output improved heated water and will be better for the environment as well.

Mike Fowler is the commercial marketing and sales manager for Pentair Aquatic Systems in Sanford, N.C. He has been with Pentair since 1992, starting his career in the technical services department at Purex Pool Products. Fowler has held many managerial roles within the company, including marketing, accounting and products. For more information, visit