Air Heater Basics Part Three: Choosing an Air Source

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.
Recommended reading in this series:

• Air Heater Basics Part One: Air Heaters Defined
• Sizing your Heater and Blower: The Relationship between Air Flow and Temperature
• Air Heater Basics Part Two: Elements
• Understanding Blowers as part of a System

Choosing an Air Source

Element type should be taken into consideration when choosing an air source.  Generally, a centrifugal blower is chosen for open element heaters; the higher pressures of a regenerative blower are not required because of the lower pressure drop across the heater. Read our article about Understanding Blowers as Part of a System for more information about pressure drop.

Regenerative blowers are often chosen for fully supported element heaters because they are capable of providing more air flow at higher operating pressures, which is necessary to compensate for the pressure drop through the heater. Although centrifugal blowers often have a much higher volumetric output capacity, a regenerative blower will generally result in a higher volumetric flow for the system as a whole when used with a high pressure drop heater. The pressure required from the blower depends strongly on the configuration of the element as the pressure drop can vary considerably from heater to heater.

Besides element type, blower choice depends on other downstream connections to the heater that might contribute to the cumulative pressure of a system as well as the specific application. For more information, download our whitepaper on blowers.

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 Four: Hot Air Blowers vs. Air Heaters