At its most basic level, an air heater works by passing air across a heated element to elevate the temperature of the air. That hot air can then be used for a variety of applications ranging from heating a space to drying parts and coatings, or from de-flashing plastic components to heating parts in a manufacturing process.
Every air heater is comprised of two main components:
Relationship between Volume of Air Flow and Temperature
There is a direct relationship between volume of air flow and temperature. For a constant heating power in kW, an increase in volume of air flow results in a decrease in the output temperature. Energy is required to increase the temperature of any solid, liquid or gas and the amount required is directly related to the mass of the material being heated. As the volume of flow increases, the mass of air to be heated also increases. There is a lower limit to volume of air flow for any heater, where temperature rises to the point where the components are damaged.
See our article on Sizing your Heater and Blower: The Relationship between Air Flow and Temperature for more information.
Many people make the mistake of choosing a heater/blower combination from a catalogue based on maximum flow or temperature values; in reality, there are many factors that influence the correct equipment choice. When you contact your heater supplier they should ask for details of your application to be sure you are choosing the appropriate equipment. If they don’t, we suggest you consider finding an alternate supplier who can ensure that the equipment you purchase is right for your application.
Continue reading: Air Heater Basics Part Two: Elements