1. TEMPERATURE DIFFERENTIAL
Determine the temperature differential (DT) to be maintained by
subtracting the ambient temperature (T
A
) from the fluid tempera
-
ture (T
F
) to be maintained (DT=T
F
-T
A
). Typically, for pipe freeze
protection applications, the pipe temperature should be main-
tained at 40°F. Pipe temperatures should be maintained at 110°F
for grease disposal lines and 40°F for fuel lines.
2. HEAT LOSS
Use Table 1 to look up the heat loss associated with the pipe
diameter and thickness of insulation. If a rigid insulation such as
calcium silicate is used, the pipe heat loss should be increased to
that associated with the next larger size. Insulation should also be
oversized when using any cable other than the standard self-reg-
ulating TSR, without overjacket. This will compensate for the space
of the heating cable. As an example, you would use 2-inch pipe
diameter heat losses for 1
1
/2 inch pipe heating application if rigid
insulation were used. heat loss figures from Table 1 include a 10%
safety factor.
3. ADJUSTMENTS TO HEAT LOSS VALUES
The heat losses in
Table 1
are based on glass fiber insulation. If
other insulations are used, multiply the heat loss value by the cor-
rection factor (shown in
Table 2
) for your insulation.
Heat losses are based on outdoor applications with 20 mph
wind. If piping is used indoors, multiply heat loss values by 0.9.
4. DETERMINE CABLE P0WER
Using heat loss determined above, select appropriate cable
from Performance and Rating Data chart. For heat loss in excess
of 10 W/ft, use multiple cables. For example, for heat loss of 13
W/ft, use two 8 W/ft cables. Cable power may exceed heat loss
by up to 50%.
It is also possible to spiral cable on pipe such that the power ap-
plied to the pipe exactly matches the pipe heat loss. For exam
-
ple, for heat loss of 13 W/ft, a 10 W/ft cable can be spiraled on
the pipe such that 1.3 feet of cable are wound on every foot of
pipe, resulting in exactly 13 W/ft being applied to the pipe.
however, spiraling requires significant extra labor to install and
significant clearance around the pipe. For this reason, we do
not recommend spiraling. For further information on spiraling,
contact Easy Heat.
Insulation
∆
T
IPS
1
/
2
3
/
4
1
1
1
/
4
1
1
/
2
2
2
1
/
2
3
4
5
8
10
12
Thickness (°F) Tubing
3
/
4
1
1
1
/
4
1
1
/
2
2
1.0"
10
0.3
0.4
0.4
0.5
0.6
0.7
0.8
0.9
1.1
1.5
1.9
2.4
2.7
(25mm) 50
1.7
1.9
2.2
2.5
2.8
3.3
3.8
4.4
5.4
7.5
9.5
11.5
13.5
100
3.5
3.9
4.5
5.3
5.8
6.8
7.9
9.2
11.3
15.7
19.8
24.5
28.2
150
5.4
6.2
7.1
8.3
9.1
10.7
12.4
14.4
17.5
24.6
31.0
37.8
44.2
200
7.5
8.6
9.9
11.5
12.6
14.9
17.2
20.0
24.5
34.2
43.2
52.6
61.5
250
9.8
11.2
12.8
15.0
16.5
19.4
22.4
26.0
31.9
44.6
56.1
68.4
80.0
1.5"
10
0.3
0.3
0.4
0.4
0.4
0.5
0.6
0.7
0.8
1.1
1.4
1.6
1.9
(38mm) 50
1.3
1.5
1.7
1.9
2.1
2.5
2.8
3.2
3l9
5.3
6.7
8.1
9.4
100
2.8
3.1
3.5
4.1
4.4
5.1
5.9
6.8
8.2
11.2
14.0
16.9
19.7
150
4.4
4.9
5.5
6.4
6.9
8.1
9.2
10.6
12.8
17.6
21.9
26.5
30.8
200
6.1
6.8
7.7
8.9
9.7
11.2
12.8
14.7
17.8
24.4
30.5
36.9
42.9
250
7.9
8.9
10.0
11.6
12.6
14.6
16.7
19.2
23.2
31.8
39.6
48.0
55.8
2.0"
10
0.2
0.3
0.3
0.4
0.4
0.4
0.65
0.5
0.6
0.9
1.1
1.3
1.5
(50mm) 50
1.2
1.3
1.4
1.6
1.7
2.0
2.3
2.6
3.1
4.2
5.2
6.3
7.3
100
2.4
2.7
3.0
3.4
3.7
4.3
4.8
5.5
6.6
8.9
11.0
13.2
15.3
150
5.4
6.2
7.1
8.3
9.1
10.7
12.4
14.4
17.5
24.6
31.0
37.8
44.2
200
5.3
5.9
6.6
7.5
8.1
9.3
10.5
12.0
14.4
19.4
24.0
28.8
33.4
250
6.9
7.7
8.6
9.8
10.67
12.1
13.7
15.6
18.7
25.3
31.2
37.5
43.5
2.5"
10
0.2
0.2
0.3
0.3
0.3
0.4
0.4
0.5
0.5
0.7
0.9
1.1
1.2
(63mm) 50
1.0
1.2
1.3
1.4
1.6
1.8
2.0
2.3
2.7
3.6
4.4
5.2
6.0
100
2.2
2.4
2.7
3.0
3.3
3.7
4.2
4.7
5.6
7.5
9.2
11.0
12.7
150
3.4
3.8
4.2
4.8
5.1
5.8
6.6
7.4
8.8
11.7
14.4
17.2
19.9
200
4.8
5.3
5.9
6.6
7.1
9.1
9.1
10.3
12.3
16.3
20.0
24.0
27.6
250
6.2
6.9
7.6
8.6
9.3
10.6
11.9
13.5
16.0
21.3
26.1
31.2
36.0
3.0"
10
0.2
0.2
0.3
0.3
0.3
0.3
0.4
0.4
0.5
0.6
0.8
0.9
1.1
(75mm) 50
1.0
1.1
1.2
1.3
1.4
1.6
1.8
2.0
2.4
3.1
3.8
4.5
5.2
100
2.0
2.2
2.5
2.8
3.0
3.4
3.7
4.2
5.0
6.5
8.0
9.5
10.9
150
3.2
3.5
3.9
4.3
4.6
5.3
5.9
6.6
7.8
10.3
12.5
14.9
17.1
200
4.4
4.9
5.4
6.0
6.5
6.7
8.2
9.2
10.8
14.3
17.4
20.7
23.8
250
5.8
6.3
7.0
7.8
8.4
9.5
10.6
12.0
14.1
18.6
22.6
26.9
30.9
Table 1 – Pipe Heat Loss, W/FT
contact easy heat for larger sizes.
©2009 Easy Heat
www.easyheat.com