Enter the heat transfer rate, mass flow rate, specific heat capacity, and temperature change into the calculator to determine the missing variable for an air to water heat exchanger.

Air To Water Heat Exchanger Calculator

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Enter any 3 values to calculate the missing variable

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Air To Water Heat Exchanger Formula

The following formula is used to calculate the heat transfer rate for an air to water heat exchanger.

Q = m \cdot c \cdot Delta T

Variables:

  • Q is the heat transfer rate in watts
  • m is the mass flow rate in kilograms per second (kg/s)
  • c is the specific heat capacity in joules per kilogram per degree Celsius (J/(kg·K))
  • ΔT is the temperature change in degrees Celsius (°C)

To calculate the heat transfer rate, multiply the mass flow rate by the specific heat capacity and the temperature change.

Watts to BTU/hr Conversion Table (Heat Transfer Rate, Q)
Watts (W) BTU/hr
100341
200682
3001024
4001365
5001706
6002047
7502559
1,0003,412
1,2004,095
1,5005,118
2,0006,824
2,5008,530
3,00010,236
3,50011,942
4,00013,649
5,00017,061
7,50025,591
10,00034,121
20,00068,243
50,000170,607
1 W ≈ 3.412142 BTU/hr • 1 BTU/hr ≈ 0.293071 W

What is an Air To Water Heat Exchanger?

An air to water heat exchanger is a device that transfers heat from air to water. It is commonly used in heating, ventilation, and air conditioning (HVAC) systems to improve energy efficiency and maintain desired temperatures. The heat exchanger works by passing air over a series of coils or plates that contain water. As the air flows over the coils, heat is transferred from the air to the water, thereby cooling the air and heating the water. This process can be reversed to transfer heat from water to air, depending on the application.

How to Calculate Air To Water Heat Exchanger?

The following steps outline how to calculate the heat transfer rate for an air to water heat exchanger.


  1. First, determine the mass flow rate (m) in kg/s.
  2. Next, determine the specific heat capacity (c) in J/(kg·K).
  3. Next, determine the temperature change (ΔT) in °C.
  4. Finally, calculate the heat transfer rate (Q) using the formula Q = m * c * ΔT.
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Mass flow rate (m) = 2 kg/s

Specific heat capacity (c) = 4186 J/(kg·K)

Temperature change (ΔT) = 10 °C