Watage Estamation Tables
Kilowatt Hours to Heat Water
| Amount of Water | Temperature Rise (°F) |
|||||||
Cubic |
Gallons |
20° |
40° |
60° |
80° |
100° |
120° |
140° |
Kilowatts to heat in one hour |
||||||||
0.67 |
5 |
0.3 |
0.5 |
0.8 |
1.1 |
1.3 |
1.6 |
1.9 |
1.3 |
10 |
0.5 |
1.1 |
1.6 |
2.2 |
2.7 |
3.2 |
3.8 |
2.0 |
15 |
0.8 |
1.6 |
2.4 |
3.2 |
4.0 |
4.8 |
5.6 |
2.7 |
20 |
1.1 |
2.2 |
3.2 |
4.3 |
5.4 |
6.5 |
7.5 |
3.3 |
25 |
1.3 |
2.7 |
4 |
5.4 |
6.7 |
8.1 |
9.4 |
4.0 |
30 |
1.6 |
3.2 |
4.8 |
6.5 |
8.1 |
9.7 |
11.3 |
5.3 |
40 |
2.2 |
4.3 |
6.5 |
8.6 |
10.8 |
12.9 |
15.1 |
6.7 |
50 |
2.7 |
5.4 |
8.1 |
10.8 |
13.5 |
16.1 |
18.8 |
8.0 |
60 |
3.2 |
6.5 |
9.7 |
12.9 |
16.1 |
19.4 |
22.6 |
9.4 |
70 |
3.8 |
7.5 |
11.3 |
15.1 |
18.8 |
22.6 |
26.4 |
10.7 |
80 |
4.3 |
8.6 |
12.9 |
17.2 |
21.5 |
25.8 |
30.1 |
12.0 |
90 |
4.8 |
9.7 |
14.5 |
19.4 |
24.2 |
29.1 |
33.9 |
13.4 |
100 |
5.4 |
10.8 |
16.1 |
21.5 |
26.9 |
32.3 |
37.7 |
16.7 |
125 |
6.7 |
13.5 |
20.2 |
26.9 |
33.6 |
40.4 |
47.1 |
20.1 |
150 |
8.1 |
16.1 |
24.2 |
32.3 |
40.4 |
48.4 |
56.5 |
23.4 |
175 |
9.4 |
18.8 |
28.2 |
37.7 |
47.1 |
56.5 |
65.9 |
26.7 |
200 |
10.8 |
21.5 |
32.3 |
43 |
53.8 |
64.6 |
75.3 |
33.4 |
250 |
13.5 |
26.9 |
40.4 |
53.8 |
67.3 |
80.7 |
94.2 |
40.1 |
300 |
16.1 |
32.3 |
48.4 |
64.6 |
80.7 |
96.9 |
113.0 |
53.5 |
400 |
21.5 |
43.0 |
64.6 |
86.1 |
107.6 |
129.1 |
150.7 |
66.8 |
500 |
26.9 |
53.8 |
80.7 |
107.6 |
134.5 |
161.4 |
188.3 |
For
Water: |
|
Equation 1 |
|
GPM x Temperature Rise (°F) x .16 |
= KW |
Equation 2 |
|
Gallons x Temperature
Rise (°F) |
= KW |
Note: 10% safety factor is included. |
|
Kilowatt Hours to Heat Oil
| Amount of Oil | Temperature Rise (°F) |
||||||
Cubic |
Gallons |
50° |
100° |
200° |
300° |
400° |
500° |
Kilowatts to heat in one hour |
|||||||
0.67 |
5 |
0.3 |
0.7 |
1.4 |
2.09 |
2.79 |
3.49 |
1.3 |
10 |
0.7 |
1.4 |
2.8 |
4.19 |
5.58 |
6.98 |
2.0 |
15 |
1 |
2.1 |
4.2 |
6.28 |
8.37 |
10.5 |
2.7 |
20 |
1.4 |
2.8 |
5.6 |
8.37 |
11.2 |
14 |
3.3 |
25 |
1.7 |
3.5 |
7 |
10.5 |
14 |
17.4 |
4.0 |
30 |
2.1 |
4.2 |
8.4 |
12.6 |
16.7 |
20.9 |
5.3 |
40 |
2.8 |
5.6 |
11 |
16.7 |
22.3 |
27.9 |
6.7 |
50 |
3.5 |
7 |
14 |
20.9 |
27.9 |
34.9 |
8.0 |
60 |
4.2 |
8.4 |
17 |
25.1 |
33.5 |
41.9 |
9.4 |
70 |
4.9 |
9.8 |
20 |
29.3 |
39.1 |
48.8 |
10.7 |
80 |
5.6 |
11 |
22 |
33.5 |
44.7 |
55.8 |
12.0 |
90 |
6.3 |
13 |
25 |
37.7 |
50.2 |
62.8 |
13.4 |
100 |
7 |
14 |
28 |
41.9 |
55.8 |
69.8 |
16.7 |
125 |
8.7 |
17 |
35 |
52.3 |
69.8 |
87.2 |
20.1 |
150 |
10 |
21 |
42 |
62.8 |
83.7 |
105 |
23.4 |
175 |
12 |
24 |
49 |
73.3 |
97.7 |
122 |
26.7 |
200 |
14 |
28 |
56 |
83.7 |
112 |
140 |
33.4 |
250 |
17 |
35 |
70 |
105 |
140 |
174 |
40.1 |
300 |
21 |
42 |
84 |
126 |
167 |
209 |
53.5 |
400 |
28 |
56 |
112 |
167 |
223 |
279 |
66.8 |
500 |
35 |
70 |
140 |
209 |
279 |
349 |
For Oil :Use equation or table |
|
Gallons x Temperature
Rise (°F) |
= KW |
Note: The above KW values are based on an average specific heat of 0.45 (btu/lb/°F) and a Density of 7.35 lb/gallon plus a 20% safety factor. This table should be used only as a guide; exact wattage requirements can be calculated using the formulas at Heat Requirement Calculations. |
|
Kilowatt Hours to Heat Air
| Amount of Air | Temperature Rise (°F) |
||||||||||
Air CFM |
50 |
100 |
150 |
200 |
250 |
300 |
350 |
400 |
450 |
500 |
600 |
100 |
1.7 |
3.3 |
5 |
6.7 |
8.3 |
10 |
11.7 |
13.3 |
15 |
16.7 |
20 |
200 |
3.3 |
6.7 |
10 |
13.3 |
16.7 |
20 |
23.3 |
26.7 |
30 |
33.3 |
40 |
300 |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
40 |
45 |
50 |
60 |
400 |
6.7 |
13.3 |
20 |
26.7 |
33.3 |
40 |
46.7 |
53.3 |
60 |
66.7 |
80 |
500 |
8.3 |
16.7 |
25 |
33.3 |
41.7 |
50 |
58.3 |
66.7 |
75 |
83.3 |
100 |
600 |
10 |
20 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
100 |
120 |
700 |
11.7 |
23.3 |
35 |
46.7 |
58.3 |
70 |
81.7 |
93.3 |
105 |
116.7 |
140 |
800 |
13.3 |
26.7 |
40 |
53.3 |
66.7 |
80 |
93.3 |
106.7 |
120 |
133.3 |
160 |
900 |
15 |
30 |
45 |
60 |
75 |
90 |
105 |
120 |
135 |
150 |
180 |
1000 |
16.7 |
33.3 |
50 |
66.7 |
83.3 |
100 |
116.7 |
133.3 |
150 |
166.7 |
200 |
1100 |
18.3 |
36.7 |
55 |
73.3 |
91.7 |
110 |
128.3 |
146.7 |
165 |
183.3 |
220 |
1200 |
20 |
40 |
60 |
80 |
100 |
120 |
140 |
160 |
180 |
200 |
240 |
| For free air: Use equation or table |
|
CFM x Temperature Rise
(°F) |
|
Use the maximum anticipated airflow. This equation assumes insulated duct (negligible heat loss) and 70°F inlet air at 14.7 PSIA |
|
For compressed air: |
|
CFM* x Density*(lbs/cu.
ft.) x Temperature rise (°F) |
|
*At heater inlet temperature and pressure |
|
Note: If air flow is given in
CFM at operating temperature and pressure it can be converted to SCFM (Standard Cubic Feet
per Minute) with the following formula. |
|
SCFM = CFM x ( P/14.7 ) x (530/T + 460) |
|
P = operating pressure (gauge pressure + 14.7) |
|
T = operating temperature |
|
SCFM = flow rate in CFM at standard conditions of 70°F and 14.7 PSIA. |