The Direct Gas Fired Make-Up Air package is designed to deliver tempered make-up air for installations requiring frequent air changes. Units are designed for natural and propane gas applications, and for indoor or outdoor installation.
Direct Gas-Fired Heater, for use in tempering make-up air. Packages are certified to the ANSI Z83.4-Second Edition and CSA 3.7-2006 combined safety standards. One size is available with a max BTU rate of 241,290 and 1,800 CFM. Units are designed for natural or propane applications and are rated for indoor/outdoor installations in commercial occupancies. A unique feature is the self-adjusting burner profile plates allowing 2-speed and variable-air-volume applications. The plates ensure proper air velocity and pressure drop across the burner for clean combustion. Spring-loaded profile plates react to the momentum of the fresh air stream, therefore, no motors or actuators are needed to drive them, nor do they need to be manually set to a specific position.
Standard features include intermittent spark ignition system with timed safety lockout, and redundant gas valves. Units consist of a galvanized enclosure with an elevated gas burner which burns directly in the air stream. The burner consists of non-clogging, stainless steel combustion baffles attached to a cast iron gas supply section. The burner is capable of nearly 100% thermal efficiency with a maximum turndown ratio of 15 to 1. The products of combustion mix with the make-up air which is introduced into the heater intake directly from outside the building. The burner module has a standard horizontal inlet and discharge duct connection and is located upstream of the blower. The heater has a standard horizontal inlet designed to accommodate an outside air inlet hood with standard 2” filter and screen.
To satisfy a variety of installation requirements, packages are available in a number of configurations which include additions of filtered intake with easy access door and a trunkline that is used to move the air intake away from the grease laden exhaust air. Screened intakes are used to stop debris from being pulled in to the heater. The screened intake attaches directly to the filtered intake or the trunkline. Combination packages that include both exhaust and supply fans mounted on a single roof curb are also available, please contact your sales representative for more information.
Features & Benefits
- G90 galvanized construction
- Easy access doors
- Pre-wired, pre-piped controls
- Horizontal or down discharge
- Adjustable drive sheaves
- Fully insulated casing
- Stainless steel burner with aluminum casting
- 120 volt control transformer with single point electrical connection
- Redundant gas valves
- Intermittent spark pilot with timed safety lockout
- Electronic flame modulation
- High temperature limit switch
- Airflow proving switch
- Economizer inlet thermostat
- Motor starter
- Disconnect switch
- Burner observation port