Gas-Fired Units: Direct vs Indirect

There are some differences between a direct gas-fired unit and an indirect gas-fired unit. Direct gas-fired units provide efficient, reliable makeup air for many high-exhaust/infiltration industrial applications and facilities, such as warehouses and factories. At the same time, a direct gas-fired units has seen little utilization in many commercial applications. Commerical kitchens are likely the most prevailing user. However, with the ever-growing energy costs, gas-fired units might be a smart use for many commercial applications. Let's take a look at some of the differences between these two types of gas-fired units and how their applications can be utilized.


When it comes to gas-fired units, there are two different types: a direct gas-fired units and an indirect gas-fired unit. It is crucial to understand the difference between these two types of units.

Direct Gas-Fired Units

A direct gas-fired AHU (air handling unit) has a gas burner that gets installed directly in the outside makeup-air stream. The products of combustion are then subsequently discharged into the makeup-air stream and then adequately supplied to the building or the process. When it comes to the units, there are non-recirculating direct has fired AHUs and recirculating direct gas-fired AHUs. We will help you choose the correct unit for your needs.

Indirect Gas-Fired Units

An indirect gas-fired AHU has a sealed combustion chamber. This is where all of the products of combustion discharge through. They do so through a flue to the outside environment. No products of combustion are discharged within the makeup air supplied to the building. Many indirect gas-fired units have a system for utilizing 100% outside air. Also, some of the equipment is frequently utilized for recirculating-air applications.

Gas-Fired AHU Supplier

Gas fired unit heaters are an effective and affordable way to heat up large areas. From garages, to warehouses, to industrial buildings, gas-fired units are a great option to use. These propane and natural gas unit heaters are vented and will offer high efficiency ratings. You can also get gas heaters approved for your home, since these heaters offer various BTUs. For more information about the gas heaters in our inventory, please reach out to us today and get an estimate.

Get an Estimate

When you reach out to our office, we can discuss all of the various options with you. Our staff will go over what works best for your given situation and provide you with options to choose from. There are various gas-fired AHUs that will work better in different situations. Once we finish up our consultation, we will help you decide on the best course of action for your heating needs. Many commercial facilities, offices, residential properties and homes in the greater New York City area turn to NorWest for gas-fired unit heaters. On top of heaters, we also supply water source units, which have many great advantages, and heating pumps

NorWest Air Conditioning and Heating Service Co is a full-service company that also performs maintenance, repairs, sales and installation of PTAC units. Over the years, we have become a leader in the NYC area for heating and air conditioning services.