Flagro THC-355CDF Ductable Direct Fired Heater
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The Flagro THC-355CDF 330,000 BTU Dual-Fuel Direct-Fired Heater provides powerful temporary heating for construction sites, commercial tents, and temporary structures with proper ventilation. Featuring propane/natural gas compatibility, thermostatic control, and ductable airflow, it is built for commercial heating applications.
Key Specifications:
- Heating: 330,000 BTU/hr
- Fuel: Propane or Natural Gas
- Airflow: Up to 2,600 CFM
- Electrical: 115V / 15A
- Thermostat: Included, 20′ Cord
- Ignition: Direct Spark
- Weight: 345 lbs
- Ducting: Optional 18″ × 12′
Included: 15′ fuel hose and large twin-stage regulator.
Nationwide shipping available. Contact us for pricing and availability.
The Flagro THC-355CDF 330,000 BTU Dual-Fuel Direct-Fired Heater delivers powerful temporary heating for commercial tents, construction sites, temporary structures, and industrial work areas. Designed for demanding applications, this box-style heater combines 330,000 BTU/hr of heating capacity, up to 2,600 CFM airflow, and propane/natural gas compatibility in one ductable heating system.
The THC-355CDF features thermostatic temperature control, direct spark ignition, and a fuel selector valve that allows the heater to be configured for either propane or natural gas according to the manufacturer’s instructions.
A remote thermostat with a 20-foot cord is included, allowing temperature monitoring away from the heater. The unit also includes a 15-foot fuel hose and large twin-stage regulator.
With optional 18-inch high-temperature ducting, the Flagro THC-355CDF can distribute heated air to suitable temporary heating applications.
Key Features of the Flagro THC-355CDF
- 330,000 BTU/hr Heating Capacity: High-output temporary heating for commercial construction and tent applications.
- Dual-Fuel Operation: Compatible with propane or natural gas.
- 2,600 CFM Airflow: High-volume heated-air circulation.
- Direct-Fired Heating: Produces heated airflow without a separate indirect-fired heat exchanger.
- Fuel Selector Valve: Allows the appropriate fuel configuration to be selected.
- Thermostatic Control: Maintains selected temperatures by controlling burner operation.
- Included Remote Thermostat: Features a 20-foot cord for convenient thermostat placement.
- Direct Spark Ignition: Provides automatic burner ignition.
- 115V Electrical Supply: Requires compatible single-phase power.
- 15-Foot Fuel Hose Included: Supplied with the manufacturer’s fuel connection equipment.
- Twin-Stage Regulator Included: Supports the specified fuel installation.
- Fan-Only Mode: Allows air circulation without burner operation.
- Optional 18-Inch Ducting: Supports approved heated-air distribution arrangements.
- Portable Commercial Construction: Designed for temporary heating applications.
- cETLus Listed: Manufacturer-listed safety certification.
Dual-Fuel Heating: Propane or Natural Gas
One of the main advantages of the Flagro THC-355CDF is its ability to operate on either propane or natural gas.
This provides flexibility for commercial contractors working at different locations.
Propane Operation
When configured for propane, the THC-355CDF delivers 330,000 BTU/hr of heating capacity.
Published propane specifications:
- Heating Input: 330,000 BTU/hr
- Fuel Consumption: 16 lbs/hr
- Inlet Pressure: 11–14 inches water column
- Burner Manifold Pressure: 7.75 inches water column
An appropriately sized vapor-propane supply, approved regulator, and compatible hose assembly are required.
Natural Gas Operation
The THC-355CDF can also operate on natural gas.
Published natural gas specifications:
- Heating Input: 330,000 BTU/hr
- Fuel Consumption: 307 cubic feet per hour
- Inlet Pressure: 9–14 inches water column
- Burner Manifold Pressure: 5.5 inches water column
The natural gas supply must provide adequate pressure and flow for the heater.
Fuel selection and connections must follow Flagro’s instructions. Fuel changes should be performed by qualified personnel where required.
Thermostatically Controlled Temporary Heating
The Flagro THC-355CDF includes thermostatic control to help regulate temperatures during temporary heating applications.
The included thermostat features a 20-foot remote cord, allowing it to be positioned in a suitable temperature-monitoring location.
The thermostat controls burner operation based on the selected temperature.
This helps contractors maintain more consistent conditions in compatible temporary structures and construction work areas.
Actual fuel consumption depends on burner operation, thermostat cycling, outdoor temperatures, and heating demand.
Common Applications for the THC-355CDF
Commercial Tent Heating
The THC-355CDF is designed for appropriately ventilated commercial tent heating applications.
Its high heating capacity, remote thermostat, and optional high-temperature ducting make it useful for larger temporary enclosures.
Applications may include:
- Commercial event tents
- Temporary event structures
- Large seasonal enclosures
- Construction tents
- Temporary work shelters
Because this is a direct-fired heater, combustion products enter the heated airflow. Proper ventilation, occupant safety, and applicable fire-code requirements must be addressed before installation.
Construction Site Heating
Construction projects frequently require temporary heat during winter operations and building renovations.
The THC-355CDF provides 330,000 BTU/hr of heating for suitable construction environments.
Common uses include:
- Commercial construction sites
- Temporary work enclosures
- Building renovations
- Winter construction projects
- Maintenance operations
- Temporary heating during HVAC installation
Warehouses and Industrial Work Areas
Large industrial projects and temporary workspaces may need supplemental heat during colder weather.
The THC-355CDF can provide directed heated airflow for suitable, adequately ventilated areas where direct-fired combustion heaters are permitted.
Temporary HVAC Applications
The unit may also support temporary heating during:
- Planned construction projects
- Commercial maintenance
- Temporary structure installations
- HVAC equipment replacement
- Seasonal construction heating
Explore Commercial Heating Applications
Flagro THC-355CDF Technical Specifications
| Specification | Flagro THC-355CDF |
|---|---|
| Model Number | THC-355CDF |
| Equipment Type | Ductable Direct-Fired Heater |
| Heating Capacity | 330,000 BTU/hr |
| Fuel Type | Propane / Natural Gas |
| Maximum Airflow | 2,600 CFM |
| Electrical Supply | 115V / 60Hz / Single Phase |
| Manufacturer-Listed Supply | 15 Amps |
| Propane Consumption | 16 lbs/hr |
| Natural Gas Consumption | 307 CFH |
| Propane Inlet Pressure | 11–14″ W.C. |
| Natural Gas Inlet Pressure | 9–14″ W.C. |
| Propane Manifold Pressure | 7.75″ W.C. |
| Natural Gas Manifold Pressure | 5.5″ W.C. |
| Ignition | Direct Spark |
| Thermostat | Included |
| Thermostat Cord | 20 Feet |
| Fuel Hose | 15 Feet, Included |
| Regulator | Large Twin-Stage, Included |
| Fan-Only Operation | Yes |
| Optional Duct | 18″ × 12′ |
| Length | 47″ |
| Width | 32″ |
| Height | 42″ |
| Net Weight | 345 lbs |
| Shipping Weight | Approximately 390 lbs |
| Certification | cETLus |
Specifications reflect Flagro’s published THC-355CDF product information. The manufacturer’s operating manual lists 2,400 CFM for an earlier configuration, while the current catalogue lists 2,600 CFM. Confirm the supplied equipment’s nameplate and manual before installation.
Electrical Requirements
The Flagro THC-355CDF requires 115V / 60Hz single-phase power for its blower, ignition system, and operating controls.
Flagro lists a 15-amp electrical supply requirement.
The manufacturer also identifies a grounded electrical connection and power supply indicator designed to alert operators to certain wiring problems.
The unit must be connected to a properly rated, grounded electrical circuit.
Confirm the actual equipment nameplate and electrical installation requirements before operation.
Optional Ducting and Accessories
Flagro offers ducting accessories specifically designed for the THC-355CDF.
THCP-WD18 — 18-Inch High-Temperature Duct
The THCP-WD18 is the manufacturer-specified heated-air duct for this heater.
Specifications:
- Diameter: 18 inches
- Length: 12 feet
- Construction: Manufacturer-specified high-temperature duct
- Application: Compatible heated-air distribution
Important: Flagro’s operating manual limits the THC-355CDF to a maximum of 12 feet of approved ducting. Do not use additional lengths or substitute ordinary HVAC ducting without manufacturer approval.
THCP-DA18 — Duct Adapter
The THCP-DA18 is the manufacturer-listed duct adapter for the THC-355CDF.
It supports appropriate installation of compatible heated-air ducting.
THCP-DD18 — Duct Diffuser
The THCP-DD18 is a compatible heated-air diffuser for the THC-355CDF ducting arrangement.
It helps distribute warm air through suitable temporary heating installations.
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Fan-Only Air Circulation Mode
The THC-355CDF includes a fan-only operating mode.
This allows the blower to circulate air without activating the gas burner.
Operators can switch between heating and air circulation using the heater’s controls.
The fan-only function is useful when airflow is needed without additional heat.
Safety and Ventilation Requirements
The Flagro THC-355CDF is a direct-fired gas heater intended for approved temporary heating applications.
Unlike indirect-fired heaters, direct-fired equipment releases combustion products into the heated airflow.
The heater must not be operated in a closed or inadequately ventilated space.
Important safety considerations include:
- Provide adequate fresh-air ventilation.
- Install the heater on a level surface.
- Use only approved propane or natural gas connections.
- Confirm correct inlet pressure and fuel selection.
- Maintain required clearances from combustible materials.
- Keep fuel cylinders an appropriate distance from the heater.
- Do not obstruct combustion air or heated-air discharge.
- Use only manufacturer-approved high-temperature ducting.
- Do not operate in spaces containing flammable vapors or combustible airborne materials.
- Follow the manufacturer’s operating manual and all applicable regulations.
Manufacturer-Listed Combustible Clearances
| Location | Minimum Clearance |
|---|---|
| Above Heater | 5 Feet |
| Front | 2 Feet |
| Sides | 1 Foot |
| Rear | 2 Feet |
Installation must follow the latest manufacturer instructions and the requirements of the authority having jurisdiction.
Why Choose the Flagro THC-355CDF?
The Flagro THC-355CDF combines 330,000 BTU/hr of direct-fired heating with propane/natural gas flexibility, thermostatic control, and high-volume airflow.
Its included remote thermostat, fuel hose, regulator, and optional ducting accessories make it useful for temporary construction and commercial tent heating applications.
For customers needing a smaller dual-fuel option, the Flagro THC-175DF provides 175,000 BTU/hr of heating.
Compare Other Flagro Direct-Fired Heaters
Climate Control Solutions supplies additional Flagro temporary heating equipment:
- Flagro THC-85P: 85,000 BTU propane direct-fired heater.
- Flagro THC-175DF: 175,000 BTU dual-fuel direct-fired heater.
- Flagro THC-355CDF: 330,000 BTU dual-fuel direct-fired heater.
Explore Commercial Heating Solutions
Frequently Asked Questions About the Flagro THC-355CDF
How much heat does the THC-355CDF produce?
The Flagro THC-355CDF provides 330,000 BTU/hr of heating capacity.
Is the THC-355CDF dual-fuel?
Yes. The heater can operate on propane or natural gas when configured according to Flagro’s instructions.
How much propane does the THC-355CDF consume?
The manufacturer lists approximately 16 pounds of propane per hour at rated operation.
How much natural gas does it consume?
Flagro lists approximately 307 cubic feet per hour at rated operation.
Does the THC-355CDF include a thermostat?
Yes. A remote thermostat with a 20-foot cord is included.
Does it include a fuel hose and regulator?
Yes. Flagro lists a 15-foot fuel hose and large twin-stage regulator as included equipment.
How much airflow does the heater provide?
The current manufacturer product listing identifies up to 2,600 CFM.
What electrical service is required?
The heater requires 115V / 60Hz single-phase power with a manufacturer-listed 15-amp supply.
What size ducting does it use?
Flagro specifies 18-inch high-temperature ducting, part number THCP-WD18.
How long can the ducting be?
The operating manual limits the heater to a maximum of 12 feet of approved ducting.
Can it run as a fan without heating?
Yes. The heater includes a fan-only circulation mode.
Can the THC-355CDF be used in enclosed structures?
Only where the installation is approved and sufficient fresh-air ventilation is provided. Direct-fired combustion products enter the heated airflow.
Request a Quote for the Flagro THC-355CDF
Climate Control Solutions supplies Flagro direct-fired heaters, ductable tent heaters, and commercial temporary heating equipment nationwide.
Whether you need one THC-355CDF for a temporary structure or multiple heaters for a construction project, our team can assist with fuel requirements, compatible ducting, equipment selection, and freight arrangements.
Contact Climate Control Solutions for current pricing and availability.
Phone: (800) 633-8711
Email: [email protected]
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