The following tables illustrate conversion factors often needed for thermal calculations.
You will find these tables to be a useful reference when selecting a cold plate, recirculating chiller, cooling system or heat exchanger for your application.
Conversion Factors
| MULTIPLY |
BY |
TO OBTAIN |
| Watts |
3.412 |
BTU/hr |
| Watts/°C |
1.896 |
BTU/hr°F |
| Horsepower |
745 |
Watts |
| CFM (Cubic Feet per Minute) |
0.028 |
m³/min |
| PSI (Pounds per Square Inch) |
0.069 |
Bars |
| PSI (Pounds per Square Inch) |
27.68 |
Inches of Water |
| GPM (Gallons per Minute) |
3.785 |
LPM (Liters per Minute) |
| Ft³ (Cubic Feet) |
7.48 |
Gallons |
| Pressure Head (Feet of Water) |
0.434 |
PSIG |
| Inches of Water |
249 |
Pascals |
| In. (Inches) |
25.4 |
mm (millimeters) |
| lbs (Pounds) |
0.454 |
kg (kilograms) |
| Tons of Refrigeration |
12,000 |
BTU/Hr |
| °F (Fahrenheit) |
5/9 (°F-32) |
°C |
| °C (Celsius) |
(1.8 x °C)+32 |
°F |
| Cp (BTU/lb°F) |
4.18 |
J/kg°C |
| Density (lb/ft³) |
16.018 |
kg/m³ |
| ΔT (°C) |
1.8 |
ΔT (°F) |
| Mass Flow (lb/hr) |
0.000126 |
kg/sec |
Temperature Conversion
| °C |
°F |
| -40 |
-40 |
| -30 |
-22 |
| -20 |
-4 |
| -10 |
14 |
| 0 |
32 |
| 10 |
50 |
| 20 |
68 |
| 30 |
86 |
| 40 |
104 |
| 50 |
122 |
| 60 |
140 |
| 70 |
158 |
| 80 |
176 |
| 90 |
194 |
| 100 |
212 |
| 110 |
230 |
| 120 |
248 |
| 130 |
266 |
| 140 |
284 |
| 150 |
302 |
| 160 |
320 |
| 170 |
338 |
| 180 |
356 |