Watlow Heater Catalog

Air Heaters Enclosure Heaters Silicone Rubber Heaters Technical Data

Determining Minimum Wattage Requirements For Enclosures This chart is an excellent guide for determining total wattage requirements for both insulated and uninsulated enclosures, assuming the box is relatively airtight.

For windy conditions, add an additional 50 percent to the wattage requirement listed.

Total Enclosure Surface Area—Square Feet (Square Meters)

2

3

4

5

6

7.5 (0.7)

9

10

15

20

25

30

40

50

(0.2)

(0.3)

(0.4)

(0.5)

(0.6)

(0.8)

(0.9)

(1.4)

(1.9)

(2.3)

(2.8)

(3.7)

(4.7)

30 10 55 15 90 20

40 10 80 20

55 15

70 20

80 20

100

120

135

205

270

335

405 100 805 195

540 130

670 160

20 (11) 40 (22) 60 (33) 80 (44) 100 (56) 120 (67) 140 (78)

25

30

35

50

65

80

110

135

160

200

245

270

405 100 605 145 805 195

540 130 805 195

670 160

1075

1340

30

35

40

50

60

65

260

320

120

160

205

245

300

365

405 100 540 130 670 160 805 195 940 225

1005

1210

1610

2010

30

55

50

60

75

90

240

290

385

480

110

160

215

270

325

400 100 500 125 600 150 700 175

485 115 605 145 725 175 845 205

1075

1340

1610

2145

2680

30

40

55

65

80

260

320

385

515

640

135

200

270

335

405 100 485 115 565 135

1005

1340

1675

2010

2680

3350

35

50

65

80

240

320

400

480

640

800

165

240

320

405 100 470 115

1210

1610

2010

2415

3220

4020

40

60

80

290

385

480

580

770

960

190

280

375

1410

1880

2345

2815

3755

4690 1120

45

70

90

340

450

560

675

900

Temperature Rise from Ambient °F (°C)

Uninsulated boxes

Insulated boxes

Silicone Rubber Enclosure Heaters Offering For a complete list of silicone rubber product offerings available for use as an enclosure heater with a thermostat, please refer to the offerings on page 119.

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