The Complete Guide to Torpedo Heaters: Everything You Need to Know

Torpedo heaters are powerful, portable heating devices that have become essential tools in construction sites, workshops, warehouses, and other large spaces requiring rapid heat delivery. Also known as salamander heaters or forced-air heaters, these cylindrical heating units combine high BTU output with directional airflow to warm spaces quickly and efficiently.

We have an in-depth look at everything you need to know about torpedo heaters, from how they work to safety considerations and practical applications.

If you’re ready to purchase and want to see our top product recommendations, check out our guide to the best torpedo heaters available today.

Key Takeaways

• Torpedo heaters are high-powered, portable heating devices designed primarily for large, well-ventilated spaces like construction sites and warehouses
• Multiple fuel options are available including propane, kerosene, diesel, natural gas, and electric, each with distinct advantages and use cases
• BTU output ranges from 30,000 to 400,000+ BTUs, with proper sizing critical for efficient heating performance
• Ventilation is essential when using fuel-burning torpedo heaters due to carbon monoxide production and oxygen consumption
• Safety features like automatic shut-off, tip-over protection, and flame-out sensors are crucial for preventing accidents
• Direct-fired models are designed for outdoor or extremely well-ventilated use, while indirect-fired models can be used in more enclosed spaces with proper venting

What Are Torpedo Heaters?

Torpedo heaters are forced-air heating devices that earned their name from their distinctive cylindrical, torpedo-like shape. These portable powerhouses operate by burning fuel or using electricity to generate heat, then employing a built-in fan to blow warm air through a directional nozzle. This design allows them to project heat across considerable distances, making them ideal for warming specific work areas or large open spaces.

The concept originated in the early 1940s when W.L. Scheu developed a high-performance space heater specifically for farmers working in harsh weather conditions. The technology has evolved significantly since then, but the fundamental principle remains unchanged: deliver maximum heat output in a portable, easy-to-deploy package.

The Mythology Behind the Name

Interestingly, the alternative name “salamander heater” comes from medieval folklore, where salamanders were mythical creatures believed to have an affinity with fire. According to legend, these beasts could control flames and even live within fire, as they often emerged from logs when tossed into a blaze. This association led traditional Spanish and Portuguese wood-burning stoves to be called “salamandras,” and the name transferred to these modern heating devices.

How Torpedo Heaters Work

Understanding the mechanics of torpedo heaters helps users operate them safely and effectively. The basic operation follows a straightforward process:

The Heating Cycle:

1. Air intake: Cold air is drawn into the heater through intake vents, typically located at the rear or sides of the unit
2. Fuel combustion or electric heating: The air passes over a heating element (electric models) or through a combustion chamber (fuel-burning models)
3. Heat transfer: In fuel models, the combustion process heats the air rapidly; in electric models, heating coils warm the passing air
4. Forced air distribution: A powerful internal fan propels the heated air through a directional nozzle at high velocity
5. Heat projection: The warm air stream travels outward, warming objects, surfaces, and the surrounding air in its path

The efficiency of this process varies by fuel type and model design. Fuel-burning torpedo heaters can achieve nearly 100% efficiency because all combustion heat (including exhaust gases) is typically released into the heated space in direct-fired models. This high efficiency comes with important safety trade-offs that we’ll discuss later.

Direct-Fired vs. Indirect-Fired Systems

A critical distinction exists between two types of torpedo heaters:

Direct-Fired Heaters blend combustion exhaust directly into the heated air stream. All byproducts of fuel combustion—including carbon monoxide, carbon dioxide, and water vapor—are expelled into the workspace. These units achieve maximum efficiency but are suitable only for outdoor use or spaces with exceptional ventilation.

Indirect-Fired Heaters feature a sealed combustion chamber surrounded by a heat exchanger. Clean air passes over the outside of this heat exchanger while exhaust gases are contained and vented outside through a dedicated flue pipe. This separation ensures clean, dry heated air is delivered indoors, making indirect-fired models the only type appropriate for enclosed occupied spaces.

Types of Torpedo Heaters

Torpedo heaters come in various configurations, each designed for specific applications and fuel availability. Understanding these distinctions helps buyers select the right heater for their needs.

Heater Type	Fuel Source	Typical BTU Range	Primary Advantages	Best Applications
Propane (LP) Torpedo	Liquid propane tanks	35,000-200,000	Portable, clean-burning, readily available fuel	Construction sites, outdoor events, workshops
Kerosene Torpedo	Kerosene	50,000-215,000	Wide coverage area, long burn times, stable fuel	Warehouses, large workshops, agricultural facilities
Diesel Torpedo	Diesel fuel (#1 or #2)	75,000-400,000+	High heat output, fuel readily available, economical for large spaces	Commercial construction, industrial sites, heavy-duty heating
Natural Gas Torpedo	Utility natural gas line	40,000-175,000	Continuous fuel supply, no refueling, cost-effective for permanent installations	Fixed-location workshops, warehouses with gas access
Electric Torpedo	Electricity (110V or 220V)	15,000-60,000	No emissions, quiet operation, safe for enclosed spaces	Indoor workshops, enclosed job sites, sensitive environments

Propane Torpedo Heaters

Propane-powered torpedo heaters rank among the most popular choices for portable heating. They connect to standard propane cylinders ranging from small 20-pound tanks to large 100-pound cylinders or even in-ground bulk tanks. The fuel burns cleanly with minimal odor when the heater is properly maintained, though adequate ventilation remains essential. For those interested in propane heating options that don’t require the same ventilation demands, consider exploring ventless propane heaters which use catalytic or infrared technology.

Key Characteristics:

• Quick setup with simple tank connection
• Portable across job sites without fuel spillage concerns
• Clean combustion produces less soot than kerosene or diesel
• Requires carbon monoxide monitoring and ventilation

Kerosene Torpedo Heaters

Kerosene heaters deliver impressive heat coverage across wide areas, making them favorites for large spaces. Kerosene is a stable, safe fuel commonly used in lanterns and lamps, though it requires more careful handling than propane during refueling. If you’re interested in other kerosene heating options beyond torpedo-style forced-air models, our guide to the best kerosene heaters covers radiant and convection models as well.

Key Characteristics:

• Extended burn times on a single fuel tank
• Wide heat distribution pattern
• More maintenance required to prevent odor and soot
• Some models accept diesel fuel as an alternative

Diesel Torpedo Heaters

Built for maximum power, diesel torpedo heaters tackle the toughest heating challenges in commercial and industrial settings. These robust units can pump out tremendous heat, with some models exceeding 400,000 BTUs. Many commercial diesel heaters are trailer-mounted for easy transportation between large job sites.

Key Characteristics:

• Highest BTU outputs available
• Fuel readily available and often already on-site for equipment
• Can typically operate on #1 or #2 diesel, sometimes kerosene
• More expensive initial cost but economical for large-scale heating needs

Natural Gas Torpedo Heaters

Natural gas models connect directly to existing utility gas lines, eliminating refueling entirely. This makes them excellent choices for permanent or semi-permanent installations in workshops and warehouses with gas service.

Key Characteristics:

• Unlimited runtime without refueling
• Lower operating costs compared to bottled fuels
• Requires professional installation for gas line connection
• Less portable than tank-based models

Electric Torpedo Heaters

Electric models use heating coils rather than fuel combustion, making them the safest option for enclosed spaces. They require no ventilation for combustion byproducts and operate nearly silently compared to their fuel-burning counterparts.

Key Characteristics:

• No emissions, fumes, or carbon monoxide
• Safe for poorly ventilated spaces
• Lower BTU output limits their effectiveness in very large areas
• Higher operating costs in areas with expensive electricity
• Requires access to adequate electrical power

Common Applications and Use Cases

Torpedo heaters excel in situations where traditional heating systems are unavailable, impractical, or insufficient. Their portability and high heat output make them versatile tools across numerous industries and applications.

Construction Sites

Construction sites represent the most common application for torpedo heaters. These heaters maintain workable conditions during cold weather, allowing projects to continue year-round. They warm partially enclosed structures, cure concrete in cold conditions, dry out wet materials, and keep workers comfortable in outdoor or unfinished buildings.

On active construction sites, torpedo heaters often work in rotation—warming an area quickly, then being shut off to conserve fuel while the space retains heat. This intermittent operation maximizes efficiency while minimizing fuel consumption and ventilation requirements.

Warehouses and Storage Facilities

Large warehouses and storage facilities present unique heating challenges. Their vast cubic footage, high ceilings, and frequent door openings make conventional heating systems expensive and inefficient. Torpedo heaters provide targeted heating in work areas or loading docks where employees spend most of their time, rather than attempting to heat the entire warehouse uniformly.

Some facilities use multiple torpedo heaters strategically positioned to create comfortable work zones while allowing the majority of the space to remain cooler. This zone heating approach dramatically reduces energy costs compared to whole-building heating.

Workshops and Garages

Home workshops and garages often lack permanent heating systems, making torpedo heaters attractive for hobbyists and professionals who need warmth while working on projects. A properly sized torpedo heater can transform a frigid garage into a comfortable workspace in 20-30 minutes, allowing projects to continue through winter months.

Workshop users often combine torpedo heaters with radiant or convection heaters—using the torpedo heater for rapid initial warm-up, then switching to a quieter, more economical heater to maintain temperature once the space reaches comfort levels.

Agricultural Facilities

Farms and ranches deploy torpedo heaters for numerous applications: warming barns during livestock births, heating greenhouses or plant nurseries, drying harvested crops, protecting equipment from freeze damage, and creating comfortable environments for animal care during extreme cold. Hunters also utilize portable heating solutions in similar outdoor applications, with deer blind heaters offering compact alternatives for smaller enclosed spaces.

The portability of torpedo heaters allows farmers to move them between different structures as needed, maximizing utility from a single unit.

Outdoor Events and Temporary Structures

Event organizers use torpedo heaters to warm tents, pavilions, and temporary structures for outdoor gatherings during cold weather. Sports teams utilize them for sideline warming areas, allowing athletes and staff to recover from cold exposure during winter games. High-end professional sports operations sometimes deploy multiple torpedo heaters in combination with heated benches and radiant warmers to create comprehensive warming stations.

Emergency and Disaster Response

Emergency response teams and disaster recovery operations rely on torpedo heaters to provide heat in situations where normal heating infrastructure is damaged or unavailable. These heaters can operate independently of electrical grids (propane, kerosene, and diesel models) and deploy quickly wherever needed.

Understanding BTU Requirements and Sizing

Proper sizing is crucial for torpedo heater performance. An undersized heater struggles to warm the space adequately, while an oversized unit wastes fuel and may create uncomfortable hot zones. The heating capacity of torpedo heaters is measured in British Thermal Units (BTUs) per hour.

Calculating Required BTUs

A standard formula helps determine appropriate heater size:

Cubic Feet of Space × Temperature Difference × 0.133 = BTUs Needed

Example Calculation:

• Space dimensions: 30 feet × 40 feet × 10 feet ceiling = 12,000 cubic feet
• Outdoor temperature: 20°F
• Desired indoor temperature: 65°F
• Temperature difference: 45°F
• Calculation: 12,000 × 45 × 0.133 = 71,820 BTUs

For this example, an 80,000 BTU heater would be appropriate, providing a slight buffer above the calculated requirement.

Factors Affecting BTU Requirements

The basic calculation provides a starting point, but several factors influence actual heating needs:

Insulation Quality: Poorly insulated spaces lose heat rapidly, requiring higher BTU capacity. Well-insulated buildings retain heat better, allowing smaller heaters to maintain comfort.

Air Infiltration: Spaces with gaps, cracks, or frequently opened doors need additional heating capacity to compensate for cold air infiltration.

Ceiling Height: Spaces with exceptionally high ceilings require more BTUs as warm air rises and useful heat accumulates above the occupied zone.

Wind Exposure: Buildings exposed to strong winds experience higher heat loss through walls and roof, necessitating increased heating capacity.

Duration of Heating: Short-term heating (warming a space for a few hours of work) may allow a smaller heater if the space can tolerate some temperature variation. All-day heating requires properly sized equipment to maintain consistent comfort.

Practical BTU Ranges

Space Type	Approximate Heating Capacity Needed	Typical Heater Size
Small Garage (1-car)	30,000-50,000 BTU	35,000-50,000 BTU propane or electric
Medium Garage (2-car)	50,000-80,000 BTU	60,000-80,000 BTU kerosene or propane
Large Workshop	80,000-150,000 BTU	100,000-125,000 BTU diesel or kerosene
Warehouse Zone	150,000-300,000+ BTU	175,000-215,000 BTU diesel
Construction Site	Variable by structure	75,000-200,000 BTU depending on size

Safety Considerations and Best Practices

Torpedo heaters are powerful tools that demand respect and careful operation. Improper use can lead to carbon monoxide poisoning, fires, explosions, or oxygen depletion. Following safety protocols is not optional—it’s essential for protecting lives and property.

The Carbon Monoxide Threat

Carbon monoxide (CO) represents the most serious hazard associated with fuel-burning torpedo heaters. This colorless, odorless gas is produced during combustion and is highly toxic. CO binds to hemoglobin in red blood cells far more readily than oxygen, effectively suffocating victims at the cellular level by preventing oxygen transport to the brain and vital organs.

Symptoms of CO Exposure:

• Headache and dizziness
• Nausea and vomiting
• Confusion and disorientation
• Fatigue and weakness
• Flu-like symptoms without fever
• Loss of consciousness (severe exposure)

The insidious nature of CO poisoning lies in its gradual onset and non-specific symptoms. Many victims mistake early CO poisoning for the flu, delaying recognition of danger until exposure becomes life-threatening.

Ventilation Requirements

Adequate ventilation is absolutely critical when operating fuel-burning torpedo heaters. Ventilation serves two purposes: removing combustion byproducts (including CO) and replacing consumed oxygen.

Minimum Ventilation Guidelines:

• Provide at least 1 square foot of ventilation opening per 100,000 BTUs of heater output
• Ensure cross-ventilation with openings on opposite sides of the space
• Never operate heaters in completely sealed rooms or enclosed spaces
• Increase ventilation if multiple people or fuel-burning equipment share the space
• In marginally ventilated areas, operate heaters intermittently rather than continuously

Even with adequate ventilation on paper, real-world conditions vary. Wind direction, temperature inversions, and building configuration can reduce ventilation effectiveness, making continuous CO monitoring essential.

Essential Safety Equipment

Carbon Monoxide Detectors: Install working CO detectors in any space where torpedo heaters operate. Consumer-grade detectors meeting UL 2034 standards provide basic protection, but commercial-grade monitors with digital readouts offer superior monitoring for job sites. According to OSHA, the maximum permissible exposure limit for carbon monoxide is 35 parts per million (ppm) averaged over an eight-hour work period.

Place detectors at breathing height, not near the ceiling where CO might accumulate. Test detectors regularly and replace batteries as recommended by the manufacturer.

Fire Extinguishers: Keep appropriate fire extinguishers nearby when operating torpedo heaters. Class ABC extinguishers handle most potential fires involving ordinary combustibles, flammable liquids, and electrical equipment.

Clearance Zones: Maintain minimum clearance distances around heaters to prevent ignition of combustible materials. Most manufacturers specify at least 3 feet (and often 5-10 feet) of clearance on all sides. Never place heaters near:

• Lumber, sawdust, or wood shavings
• Paper products or cardboard
• Fabric, curtains, or tarps
• Paint, solvents, or other flammable liquids
• Dust or debris accumulations
• Insulation materials

Built-In Safety Features

Modern torpedo heaters incorporate numerous safety features to reduce risks:

Automatic Shut-Off Systems cut fuel and power if dangerous conditions occur, including flame-out detection (shuts down if flame extinguishes), tip-over switches (shuts down if heater tips beyond safe angle), and low-oxygen sensors (shuts down if oxygen levels drop dangerously low).

Thermostatic Controls prevent overheating by cycling the heater on and off to maintain desired temperature, reducing continuous runtime and associated risks.

Electronic Ignition eliminates open pilot lights, reducing ignition source hazards when the heater isn’t actively heating.

Heavy-Duty Construction includes reinforced frames, stable bases, and protective grilles around hot components to minimize tip-over and burn risks.

Operational Safety Protocols

Pre-Operation Inspection:

• Check fuel lines and connections for leaks or damage
• Verify all safety guards and grilles are in place
• Ensure the heating area has adequate ventilation
• Remove all flammable materials from the clearance zone
• Test CO detectors to confirm they’re functioning

During Operation:

• Never leave operating heaters unattended
• Monitor CO detector readings regularly
• Watch for warning signs like unusual odors, excessive soot, yellow flames (should be blue), or people experiencing headaches or nausea
• Maintain consistent ventilation—don’t close doors or windows that were open during heater startup

Refueling Safety:

• Always shut down and allow the heater to cool completely before refueling
• Refuel outdoors or in extremely well-ventilated areas, never in enclosed spaces
• Wipe up any fuel spills immediately
• Store fuel containers away from heaters and other ignition sources
• Use only the fuel type specified by the manufacturer

Shutdown and Storage:

• Allow heaters to cool completely before moving or storing
• Drain fuel from kerosene and diesel models if storing for extended periods
• Store in dry locations protected from weather
• Keep stored heaters away from living spaces to prevent accidental tip-over or tampering

Indoor Use Considerations

The question “Can you use a torpedo heater indoors?” demands a nuanced answer. Standard direct-fired torpedo heaters are designed for outdoor use or extremely well-ventilated spaces—they are not safe for typical indoor residential use in living spaces, bedrooms, or small workshops.

Limited exceptions exist:

• Indirect-fired models with proper venting can be used in enclosed spaces, similar to permanent heating systems
• Electric torpedo heaters produce no combustion byproducts and are safe for indoor use
• Large, industrial spaces (open warehouses, aircraft hangars) with massive air volumes and active ventilation systems may safely accommodate direct-fired heaters

For typical homeowners wanting to heat a garage or workshop, electric torpedo heaters or properly vented indirect-fired models are the only safe choices for fully enclosed spaces.

Maintenance and Troubleshooting

Regular maintenance extends torpedo heater lifespan and ensures safe, efficient operation. Neglected heaters develop problems that reduce performance and increase safety risks.

Routine Maintenance Tasks

Monthly During Use:

• Clean or replace air filters to maintain proper airflow
• Inspect fuel lines and connections for cracks, wear, or leaks
• Check electrical cords for damage
• Test all safety features including automatic shut-offs
• Clean exterior surfaces of dust and debris

Annually or Before Heating Season:

• Disassemble and thoroughly clean the combustion chamber (fuel models)
• Inspect and clean the burner nozzle
• Check and adjust fuel pump pressure (if applicable)
• Lubricate fan motor bearings according to manufacturer specifications
• Replace worn ignition components
• Verify proper flame color and pattern

Kerosene and Diesel Heaters Specifically:

• Use high-quality fuel and consider fuel additives to prevent gelling in cold weather
• Change fuel filters regularly as they accumulate dirt and water
• Burn off accumulated carbon deposits by running the heater at full output for 15-20 minutes periodically

Common Problems and Solutions

Problem: Heater won’t ignite

• Check fuel level and supply
• Verify electrical connection and test circuit
• Inspect igniter or glow plug for damage
• Ensure adequate fuel pump pressure
• Check for air locks in fuel lines

Problem: Excessive smoke or soot

• Clean clogged burner nozzle
• Adjust air-to-fuel ratio
• Check for water contamination in fuel
• Verify proper fuel type is being used
• Clean combustion chamber of carbon buildup

Problem: Weak heat output

• Clean or replace clogged air filters
• Verify fuel pump is delivering correct pressure
• Check for partially clogged burner nozzle
• Ensure fan motor is running at full speed
• Inspect for exhaust blockages

Problem: Unit shuts down unexpectedly

• Check for activated safety switches
• Verify adequate ventilation (low-oxygen sensor)
• Ensure heater is level (tip-over switch)
• Check for overheating due to blocked airflow
• Inspect flame sensor for dirt or misalignment

Problem: Strong fuel odor

• Tighten all fuel connections
• Check for fuel tank leaks
• Verify proper ventilation to disperse normal combustion odors
• Inspect for incomplete combustion causing unburned fuel odor
• Ensure burner is adjusted correctly

Comparing Torpedo Heaters to Alternative Heating Solutions

Torpedo heaters excel in specific applications but aren’t always the best choice. Understanding alternatives helps make informed decisions.

Radiant Heaters

Radiant (infrared) heaters warm objects and people directly rather than heating air. They work well for spot heating in large spaces where air movement would dissipate forced-air heat.

Advantages over torpedo heaters: Quieter operation, no air movement (less dust circulation), more comfortable in drafty spaces

Disadvantages: Slower whole-space heating, limited range, must be positioned for direct line-of-sight to warming targets

Convection Heaters

Convection heaters warm air through natural circulation rather than forced air. They’re quieter and gentler than torpedo heaters. Oil-filled radiator heaters represent one popular type of convection heater, offering silent operation and safe continuous heating.

Advantages over torpedo heaters: Silent operation, even heat distribution, safe for continuous operation

Disadvantages: Much slower heat delivery, insufficient for rapid warm-up, lower BTU outputs

Permanent Heating Systems

For spaces with regular heating needs, permanent systems (furnaces, boilers, unit heaters) offer superior long-term solutions. Residential alternatives like gas heaters, pellet stoves, or freestanding gas fireplaces provide permanent warmth with better efficiency and safety profiles for home use.

Advantages over torpedo heaters: Lower operating costs, integrated with building systems, better safety, hands-off operation

Disadvantages: High installation costs, lack portability, impractical for temporary heating needs

Frequently Asked Questions

Can torpedo heaters run on multiple fuel types?

Many kerosene torpedo heaters can also burn diesel fuel (#1 or #2), though performance and odor may vary slightly. Some manufacturers explicitly design multi-fuel heaters that accept kerosene, diesel, or fuel oil. However, propane heaters cannot run on liquid fuels, and electric heaters obviously require electricity. Always consult your specific heater’s manual before using alternative fuels, as using incorrect fuel voids warranties and creates safety hazards.

How long will a torpedo heater run on a tank of fuel?

Runtime depends on BTU output, fuel type, and tank size. A 70,000 BTU kerosene heater with a 5-gallon tank typically runs 10-14 hours on a single fill. Propane heaters using a standard 20-pound cylinder at 60,000 BTUs run approximately 10-12 hours.

Diesel heaters often have larger fuel tanks and longer runtimes, sometimes exceeding 15-20 hours for industrial models. Electric heaters run indefinitely while powered. These are estimates—actual runtime varies with thermostat settings and environmental conditions.

Are torpedo heaters safe to use in garages?

Torpedo heaters can be used in garages, but safety requires strict adherence to ventilation guidelines. Open the garage door at least partially to ensure adequate air exchange, install working carbon monoxide detectors, maintain proper clearance from vehicles and stored materials, and never leave the heater unattended or run it overnight.

Electric torpedo heaters are the safest choice for garages with limited ventilation. For fully enclosed garages used frequently, consider investing in a vented indirect-fired heater or permanent heating system instead.

Why does my torpedo heater smell?

Some fuel odor is normal, especially during startup and shutdown as unburned fuel vapors dissipate. However, strong persistent odors indicate problems such as incomplete combustion from a dirty burner, fuel leaks from tank or line connections, poor-quality or contaminated fuel, or inadequate ventilation allowing combustion byproducts to accumulate.

Kerosene and diesel heaters naturally produce more odor than propane models. If odor is excessive, shut down the heater, ventilate the area, and inspect for mechanical issues before restarting.

What’s the difference between a torpedo heater and a salamander heater?

These terms refer to the same type of heater—forced-air heating devices with cylindrical bodies. “Torpedo heater” describes the shape, while “salamander heater” references the folklore association. Some users distinguish between them based on size (salamanders being larger industrial units) or fuel type, but no industry-standard definition separates the two terms. Both names are used interchangeably in most contexts.

Making the Right Choice

Torpedo heaters deliver powerful, portable heating for applications where traditional systems fall short. Their versatility across construction, industrial, agricultural, and emergency applications makes them valuable tools for professionals and homeowners alike.

Success with torpedo heaters requires understanding their capabilities and limitations. Proper sizing ensures adequate heat delivery without wasting fuel. Strict adherence to ventilation and safety protocols prevents the serious hazards these heaters can pose when misused. Regular maintenance keeps heaters running efficiently and safely season after season.

For those looking to purchase a torpedo heater, researching specific models, comparing features, and understanding your particular heating needs are essential steps. If you’re ready to invest in a torpedo heater and want detailed product recommendations, check out our comprehensive guide to the best torpedo heaters on the market today.

Whether you’re a contractor heating a job site, a farmer protecting livestock, a homeowner warming a workshop, or an event organizer creating comfortable spaces, torpedo heaters provide reliable heat when and where you need it most—as long as you use them wisely and safely.