Go Swimming Pool!

Tamara H asked:


If the price of electrical energy is 0.159 dollars per kilo-watt hour, what is the dollar cost of using electrical energy to heat the water in a swimming pool (11.8 m x 11.4 m x 1.73 m) from 13.0 to 26.7 degrees C?

Armando

2 Responses to “What is the dollar cost of using electrical energy to heat the water in a swimming pool?”

1. lasiy1961 Says:
   January 25th, 2010 at 11:23 pm

   Idalia

   Q=cm(deltaT)

   Specific Heat for Water= 4186J/kg*C

   Cubic Meters of Water = x1000 liters of Water = Mass in Kg
   (11.8×11.4×1.73)= 232.7 m^3 =232700 liters = 232700 kg

   deltaT=(26.7-13.0)= 13.7 C

   4186*232,700*13.7 = 1.33E10 J

   1 kWh = 3.6E6 J

   1.33E10 / 3.6E6 = 3694 kWh

   3694 kWh * 0.159 = $587

   This formula works, I just got it right on my Wiley Plus

2. telovelace Says:
   January 26th, 2010 at 6:09 am

   Davida

   It sounds like you are asking a textbook question as opposed to a real world question. In reality is depends on the outside air temperature, the wind, and the relative humidity to determine how much of the heat that you are putting into the pool is going to the atmosphere. If it is a sunny day there is insolation that will heat the water as well.

   So it depend on whether you are in Las Vegas or Antarctica to know whether the cost is $0 or infinity, because in Antarctica you have too much heat loss to keep the pool from freezing.