# Useful Formulas and Conversions

###
Temperature Rise Across a Heat Load:

Liquid Cooling Systems

In a liquid cooled system the heat rise of the coolant across a load can be related to its flow rate and the heat load by the general formula:

**
P = F×ΔT×SG×SH×145.7
or
ΔT = P/(F×SG×SH×145.7)
**

Where:

P = Power or heat load, in Watts

F = Flow Rate, GPM

**
Δ
**
T = Temperature rise of the coolant, °F

SG = Specific gravity of the coolant at average coolant temp.

SH = Specific heat of the coolant at average coolant temp., Btu/(lb
m
**
×
**
°F)

If the specific gravity and specific heat of the coolant are not known use "K" from the coolant selection chart , assuming 100°F average coolant temperature, in the following formula:

**
P = F×ΔT×K
or
ΔT = P/(F×K)
**

###
Temperature Rise Across a Heat Load:

Air Cooling Systems

Air temperature rise across a heat load can be related to the air flow rate and the heat load by a similar formula:

**
P = C×ΔT×D×SH×17.58
or
ΔT = P/(C×D×SH×17.58)
**

Where:

P = Power or heat load, in Watts

C = Flow Rate, CFM

**
Δ
**
T = Temperature rise of the air, °F

D = Density of the air at average temp., lb
m
/ft³

SH = Specific heat of the air at average temp., Btu/(lb
m
×°F)

If the density and specific heat of the air are not known use "K" from the coolant selection chart , assuming 70°F average air temperature at sea level, in the following formula:

**
P = C×ΔT×K
or
ΔT = P/(C×K)
**

### Power Conversion Factors

**
1W = 3.413 Btu/hr
1HP = 745.7 W
**

### Flow Conversion Factors

**
1 LPM = .264 GPM
**

### Specific Heat Conversion Factors

**
1kj/(kg × °C) = .23885 Btu/(lb
m
× °F)
**

### Density Conversion Factors

**
1kg/m
^{
3
}
= .062428 lbm/ft
^{
3
}
**

### Pressure Conversion Factors

**
1kPa = .145 psi
1 psi = 2.307 ft head
**

### Temperature Conversion Factors

**
°F = °C × (9/5) + 32
°C = (°F-32) × (5/9)
K = °C + 273.15
**

### Temperature Converter

**
Type a value in any of the fields to convert between temperature measurements:
**

**
Fahrenheit
**

**
Celsius
**

**
Kelvin
**