However there are some cases where an indirect fired heater is the better choice.
Direct fired heater efficiency.
Direct fired air heaters are typically less expensive and more efficient than indirect fired units as direct firing units converts nearly 100 of the combustion gases used to hot air.
A direct fired heater is a style of heater in which a burner provides hot gasses that transfer their heat energy to a process liquid or gas flowing directly through coils installed inside the heater vessel.
Direct fired gas heating is one of the simplest and most cost effective methods for heating air.
Having a thorough understanding of all of the differences between these two heater types will ensure you choose the optimal solution for each project.
Direct fired heaters may also heat fluid using radiant and convection heating.
Direct fired heaters can utilize radiant and or convection heat transfer sections and can be configured in many different ways depending.
Below is a diagram of a direct fired air heater.
Outside air enters the unit at point c and is either filtered or not.
Direct fired heaters are both more efficient and less expensive than indirect fired heaters.
For example a steam heating coil is supplied by a boiler has a maximum efficiency of 80 percent and experiences distribution piping energy losses.
Because the temperature in both sections is very high an intermediate heat transfer fluid is typically used.
Although the example illustrates the energy savings of direct gas fired vs.
There is a wide variety of heating configurations.
Having a thorough understanding of all of the differences between these two heater types will ensure you choose the optimal solution for each project.
Indirect gas fired ahus direct gas fired ahus are attractive when compared with most other heating sources.
Choice depends on fuel cost thermal efficiency temperature desired size of the heat load.
If desired a quantity of returning room air can be added b to this outside air in a balanced fashion to assure a constant total airflow.
Efficiency direct fired heaters convert 100 of the fuel being used to direct heat which lowers fuel consumption and operating costs easy to transport direct fired heaters are fairly simple pieces of equipment that can be moved to where heat is needed.
However there are some cases where an indirect fired heater is the better choice.