MELBOURNE FLORIDA, AQUA CAL POOL HEATER PERFORMANCE
When the night time temperatures drop into the 40's or God-Forbid, the upper 30's, we turn the pool heater OFF. It becomes almost impossible to keep it hot enough for physical therapy.
This year we turned it OFF in January and did not turn it back ON until February 17, 2022. We carefully watched the forecasts for when nighttime temps would only fall to 55 or higher. Finally we got a clear couple of weeks and turned the Heater ON.
For this sort of warm-up the electric heat-pump will need to run 24-7 so I removed the OFF stop on the mechanical timer which controls the water pump (which in-turn controls the heater).
MEASURING THE WATER TEMPERATURE
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| Note little black box hanging from drum stick = aquarium thermometer |
Temperature probe hangs in the water beneath the thermometer
We found these aquarium thermometer sensors on Amazon. They are more reliable and tested more accurate than any of the so-called pool thermometers we tried (over a dozen models the first couple of years). These aquarium thermometers are not water proof so I suspended it from a drum stick under a protective stool. Mary stores her fins on the lower shelf to keep them away from ants.
THE RESULTS ARE IN
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| Start time = 7:30am, Heater OFF = 4:30pm following day, 33-straight hours running |
On the index card of temperature readings you'll see it says 66-degrees as the starting temp. That is wrong, that was the starting temp on-the-heater display. All the other temperatures on this card are from the thermometer we have in the pool. This means the starting temperature was less than 65.3, I'd guess something like 64.3 since, as we'll see, the heater raises the cold water almost a full degree per hour once the sun is shining and ambient air temperature is mid-70's to low-80's.
HEATING ANALYSIS
The heater was able to raise the pool almost 1-degree per hour during daytime sunlight hours. The sun is all the way down around 6:30 and you can see the rate of increase slowed to a little more than .5-degrees per hour in the 6:30-8:30 time slot. Also keep in mind that the air temperature by 8:30pm is starting to drop and that takes a toll on the warming progress.
8:30pm - 8:30am (12-hour continuous run) = 6+ degrees of temperature increase even with the outdoor air temp dropping to lower 50's.
8:30am to 4:30pm = 8-straight hours of heating in daylight. The heater basically raised the pool water temperature 1-degree/hour. We shut it off at 4:30pm and I finally had my physical therapy session, ahhhhh wonderful warm water.
33-straight hours of running to heat the pool to 90-degrees.
If you compare the energy cost of heating our pool to the cost of physical therapy at a medical center this pool is a bargain and the results have been better than the therapists predicted. As long as I keep lifting weights and swimming I'm able to maintain full range of motion from my once paralyzed right-arm.
POWER USAGE ANALYSIS
I got the regular yearly maintenance done on the pool heater in January this year. Everything checked out well and it was the first time I got a chance to read the amperage since I reworked all the pump plumbing.
Repiping and eliminating right-angle piping inefficiencies lowered the amperage draw from 33-35 down to 26 amps with heater and compressor operating.
240-volts x 26-amps = 6240 watts or 6.24 kWh when heater is heating.
6.24 kWh x .12-cents /kWh = 75-cents per hour heating cost.
33-hours x .75-cents/hour = $24.50 to get the pool back up to 90.
NOW THAT THE POOL IS BACK TO HOT
The heater typically runs from 3:30am-7:30am to maintain temperature of around 88-degrees. During daylight hours with ambient temperature of 80+ degrees the heater can raise the temp to 90 at a rate of 2-hours/degree of increase. We usually like to do physical therapy around 7pm after the chickens are put to bed and all our farm chores are complete. Sometimes we do therapy at around 2pm.
THE POOL IS AWESOME
The swimming pool is our favorite toy. The pool is one of the primary reasons I was able to get my right arm moving again after fracturing my neck in three-places. Doctors and surgeons had no ideas or predictions, only experiments they could perform on me.
My amazing and beautiful partner Mary kept the faith and helped me every day to regain use of my right arm and to write and play some of the best music I've ever created. Her encouragement and help got me into the gym and pool to work on getting my body working again.
Real Love is amazing and more powerful than words!
