DC Water Heating Temperatures
How many watts will it take to heat a given amount of water?
Use the handy chart below that our General Manager David McDaris created to figure how many watts per hour you need to heat water using a DC water heating element. Whether it's a stock tank, water for chickens or other animals, fountain or a converted water heater for your home, this chart will help in sizing your water heating element.
If it's overheating you're worried about, make sure you add a thermostat to your setup. To keep water from freezing, add our freeze-stat.
How many watts does it take to heat a gallon of water?
As a general rule of thumb, it requires 2.47 watts of power to raise the temperature of one gallon of water one degree in one hour.
Formula: 2.47 Watts x 1 Gallon x 1°F in 1 Hour
Wattage Chart
| Degrees (°F) | 1 | 5 | 10 | 15 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gallons | Wattage Needed Per 1 Hour | ||||||||||||
| 1 | 2.47 | 12.35 | 24.7 | 37.05 | 49.4 | 74.1 | 98.8 | 123.5 | 148.2 | 172.9 | 197.6 | 222.3 | 247 |
| 5 | 12.35 | 61.75 | 123.5 | 185.25 | 247 | 370.5 | 494 | 617.5 | 741 | 864.5 | 988 | 1111.5 | 1235 |
| 10 | 24.7 | 123.5 | 247 | 370.5 | 494 | 741 | 988 | 1235 | 1482 | 1729 | 1976 | 2223 | 2470 |
| 20 | 49.4 | 247 | 494 | 741 | 988 | 1482 | 1976 | 2470 | 2964 | 3458 | 3952 | 4446 | 4940 |
| 30 | 74.1 | 370.5 | 741 | 1111.5 | 1482 | 2223 | 2964 | 3705 | 4446 | 5187 | 5928 | 6669 | 7410 |
| 40 | 98.8 | 494 | 988 | 1482 | 1976 | 2964 | 3952 | 4940 | 5928 | 6916 | 7904 | 8892 | 9880 |
| 50 | 123.5 | 617.5 | 1235 | 1852.5 | 2470 | 3705 | 4940 | 6175 | 7410 | 8645 | 9880 | 11115 | 12350 |
| 75 | 185.25 | 926.25 | 1852.5 | 2778.75 | 3705 | 5557.5 | 7410 | 9262.5 | 11115 | 12967.5 | 14820 | 16672.5 | 18525 |
| 100 | 247 | 1235 | 2470 | 3705 | 4940 | 7410 | 9880 | 12350 | 14820 | 17290 | 19760 | 22230 | 24700 |
| 200 | 494 | 2470 | 4940 | 7410 | 9880 | 14820 | 19760 | 24700 | 29640 | 34580 | 39520 | 44460 | 49400 |
Source: Missouri Wind and Solar © 2020
Looking for the right DC Water Heating Element?
We have different styles and voltages that are right for the job.