GM-IBT - Modular Indirect-Fired Bent Tube Heater

Air Volume: 800-20000 CFM
Maximum SP: 3" wg. @ standard air density

Product Overview

The Modular Indirect Fired Bent Tube Heater is designed to deliver clean air into an indoor environment. Units are designed for indoor or outdoor installation, and can use either Natural or LP gas. The standard unit includes a blower module and the GM-IBT heater module that is approved in the United States and Canada. The unit is listed to the ANSI Z83.8-2006 and CSA 2.6-2006 standards. Each furnace has a 6:1 Turndown Ratio and a maximum Turndown of 28:1 for the entire unit, depending on total required BTU Capacity and number of furnaces in the unit.

Every unit is programmed to start in high fire mode to ensure consistent light-off and is equipped with an electronic, Vernier-type fully-modulating control system. The duct furnaces are all type-409 stainless steel, and certified by the American Gas Association and approved by the Canadian Gas Association. Each model utilizes a single modulating stage, and between zero and three additional ON/OFF stages depending on the required heat output. In addition, the speed of its power-vent blower on the single modulating furnace is varied as the gas flow changes, thereby maintaining a constant 80% combustion efficiency over the entire gas-firing range of the unit.

Features & Benefits
• Bent Tube In-Shot Style Furnace with Type 409 Stainless Steel Heat Exchanger
• 80% Constant Efficiency over Entire Gas Firing Range
• 6:1 Turndown per Furnace, 28:1 Max
• Full Electronic Vernier-type Modulation
• Forced High Fire Start
• Variable Speed Power-vent Motor
• Discharge, Space or Building Automation System (BAS) Temperature Control
• Isolated and Insulated Electrical Controls Vestibule
• Natural Gas or Liquid Propane Applications
• Inlet and Manifold Gas Pressure Indicating Gauges
• Electronic Push Button adjustment for the Modulating Gas Valve
• High Temperature Limit Switch
• Flame Rollout Switch with Manual Reset
• LED Indicators for Troubleshooting
• Economizer Inlet Air Thermostat

• 5:1 Turndown for Propane (LP) per Furnace. 23:1 Max
• Up Discharge
• Motorized Intake Damper
• Remote Control Panel
• High and Low Gas Pressure Switch
• Mixing Box
• Variable Air Volume (VAV) Controls
• Double Wall Construction
• Blower on Delay (Heat Exchanger Pre-heat)
• Freeze-stat Option
• Fire-stat Option
• Convenience Outlet
• Extended Drop
• Single Point Electrical Connection
• Control Cabinet Heater
• Dirty Filter Airflow Switch
• Auxiliary Starters
• Roof Curbs
• Indoor Hanging Cradle


The GM-IBT Model has been certified by ITS. This certification mark indicates that the product has been tested to and has met the minimum requirements of a widely recognized (consensus) U.S. products safety standard, that the manufacturing site has been audited, and that the applicant has agreed to a program of periodic factory follow-up inspections to verify continued performance.

Model GM-IBT is ETL Listed under file number 3137380COL-002 and complies with ANSI Z83.8-2006 and CSA 2.6-2006 Standards.