2018-09-27

Air duct electric heater

To design the power of a ducted electric heater, we need to know two parameters:

Air volume of atmospheric pressure fan (cubic meters per hour)

Temperature difference

Then you can use the formula to calculate:

Actual power required = air volume of atmospheric pressure fan * temperature difference / 3600

E.g:

The air volume is 5000 cubic meters per hour, which needs to be increased from minus 10 degrees Celsius to room temperature 18 degrees Celsius, and the temperature difference is 28 degrees. Calculated by the above formula.

Actual power required = 5000 * 28 / 3600 = 38kw

How to measure the air volume

Air volume (Q): The air volume, also known as the volume flow rate, refers to the flow rate of the airflow through the cross-sectional area of the air duct. The method for measuring the wind speed is as follows;

Air outlet of rectangular or square area

First, use an anemometer to measure the average wind speed at each point of the area = m / s (m / s)

Calculate the area of the tuyere = length × width (m2)

Area * average wind speed * 60 = air volume (m / min) Also known as CMM

CMM×35.3146=CFM (cubic feet per minute)

Round air outlet

Same as above, first measure the average wind speed at each point of the area

Calculate the area of the tuyere = πr (π is the pi, r is the radius)

Area * average wind speed * 60 = air volume (m / min) Also known as CMM

CMM×35.3146=CFM (cubic feet per minute)

Unit symbol

Q (air volume) = m / min

V (wind speed) = m / sec

A (cross-sectional area) = m2

Common unit conversion table air volume

1m/min(CMM)=1000 L/min = 35.31 ft3/min(CFM)

Note that after calculating the air volume, calculate the power to be designed for the electric heater in cubic meters per hour!

The above calculation formula is for your reference and I hope to help you.