Re: Energy Kinetics System 2000 - Water Heating Question

The 121,000 BTU comes from the side of an EK1, when it burns 1 gallon of oil per hour. You can also get it from http://www.energykinetics.com/pdf/OilHeat.pdf

The 9000W comes from the Rheem site which says two 4500W elements. A watt-hour is 3.41 BTU/h (from Wikipedia), which is why I got 30690 BTUs for the electric. They claim 21 gallons at a 90 degree rise.

The recovery rate is basically how much heat the system can put into the water during an hour. If you have colder incoming water you need to input more heat than with warmer incoming water (say the difference between NH in the winter and FL in the "winter"). So the 90 degree rise is how much they are assuming you want to increase the temperature of the water (Energy Kinetics bases it off 77 degrees instead).

1 BTU raises 1 pound of water 1 degree, so you need 8.3 BTUs to raise a gallon of water 1 degree. Lets assume we want to raise the water 90 degrees. That means we need 747 BTUs per gallon of water (8.3 * 90) we want to heat. For the System 2000 that means we have 121,000/747 = 161 gallons of new hot water in an hour. For the electric we have 30690/747 = 41 gallons, but that is assuming perfect efficiency for electric. The manufacturers must know that not all of the electricity is getting converted into heated water (or it can't really use 9000W) in their calculations (which is why they have a lower number than 41 gallons).

Originally posted by

**kwfrancis**View PostThe 9000W comes from the Rheem site which says two 4500W elements. A watt-hour is 3.41 BTU/h (from Wikipedia), which is why I got 30690 BTUs for the electric. They claim 21 gallons at a 90 degree rise.

The recovery rate is basically how much heat the system can put into the water during an hour. If you have colder incoming water you need to input more heat than with warmer incoming water (say the difference between NH in the winter and FL in the "winter"). So the 90 degree rise is how much they are assuming you want to increase the temperature of the water (Energy Kinetics bases it off 77 degrees instead).

1 BTU raises 1 pound of water 1 degree, so you need 8.3 BTUs to raise a gallon of water 1 degree. Lets assume we want to raise the water 90 degrees. That means we need 747 BTUs per gallon of water (8.3 * 90) we want to heat. For the System 2000 that means we have 121,000/747 = 161 gallons of new hot water in an hour. For the electric we have 30690/747 = 41 gallons, but that is assuming perfect efficiency for electric. The manufacturers must know that not all of the electricity is getting converted into heated water (or it can't really use 9000W) in their calculations (which is why they have a lower number than 41 gallons).

## Comment