Update on the pool project
*Replaced and Stained 400 LF of 6’ Cedar Fence with 2x6 rot boards
*Installed 11 Little Gem Magnolias
*Placed 14 cubic yards of Rainbow Gravel
*Installed 3 pallets of sod
*Added thermal covers and reel
*Heated up pool
Some fun calculations for pool nerds on the initial pool heat-up. [emoji851][emoji851][emoji851]
THEORETICAL
85,000 Gallons * 8.3454 Pounds/Gallon = 709,359 Pounds of water
Measured Temp Beginning: 59.5 Degrees F
Measured Temp End: 76.6 Degrees F
709,359 * (76.6 – 59.5) = 12,130,039 BTU
Master-temp HD 400K BTU efficiency: 82%
Natural Gas heat factor: 1.030
Theoretical Natural Gas BTU’s required: 12,130,039 / 0.82 = 14,792,730 BTU
Theoretical Natural Gas CF required @ 1,030 BTU/CF: 14,362 CF
ACTUAL
Beginning Meter Read: 47,300 Cubic Foot.
End Meter Read: 65,500 cubic foot
Metered consumption: 18,200 CF
2 pound meter factor: 1.1173
Total Cubic Footage Consumed: 20,335 CF
(Total BTU’s consumed: 20,945,050)
Price per cubic foot: $0.0062352
Price: $126.79
Assumption on difference between theoretical and actual: 6,000,000 BTU energy lost through *Radiant heat loss through cover and equipment
*Heating up pool shell
*Heating the dirt surrounding shell and pipes
Prior to the covers, I was losing between 1/4” and 1/2” of water a day to evaporation in the relatively dry air of a Houston ‘winter.’
That worked out to about 450 gallons a day, or 8,729 BTU/ gallon x 450 gallons ~ 4 MMBTU.
It wasn’t worth trying to heat it as it would cost $31 a day in gas just to counteract the evaporation portion of the heat loss.
I’ll keep an eye on the ongoing gas consumption to maintain swimming temperature water and update later on.