Best Propane Barn Heater Choices for Large and Small Spaces

Choosing the right propane barn heater depends on barn size, ventilation, and whether you need radiant or forced-air heat. The table below summarizes the five propane-capable units covered in this guide, showing their BTU output and typical coverage to help you compare at a glance.

Product	BTU	Typical Coverage	Fuel Type
ProTemp 80,000 BTU LP Convection Heater	80,000	Up To 1,800 Sq Ft	Propane (20 lb Tank)
ProTemp 125,000 BTU LP Forced-Air Heater	125,000	Up To 3,125 Sq Ft	Propane
Mr. Heater 125,000 BTU Forced Air Propane Heater	125,000	Large Warehouses/Barns	Propane
Mr. Heater F260560 Big Maxx (LP Convertible)	80,000	Up To 2,000 Sq Ft	Natural Gas (Includes LP Conversion Kit)
Mr. Heater Portable Buddy MH9BX (4,000–9,000 BTU)	4,000–9,000	Up To 225 Sq Ft	Propane (Portable)

ProTemp 80,000 BTU LP Convection Heater

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This ProTemp convection unit is CSA certified and designed to heat large enclosed spaces such as garages, barns, and workshops. It connects to a standard 20 lb propane tank and is rated to heat up to about 1,800 square feet. The convection design circulates warm air throughout the space without forced-air fans, offering steady ambient warmth.

Key features include CSA safety certification, compatibility with 20 lb LP tanks, and a focus on even heat distribution. Installation typically requires adequate clearance and proper venting per local codes. This model is a practical choice when you want a simple, code-certified convection heater for medium-to-large barn sections without complex ducting.

ProTemp 125,000 BTU LP Forced-Air Heater

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The ProTemp 125,000 BTU model is a forced-air propane heater engineered for larger barns and workshops, with an airflow rating up to 12,000 CFM using matched motors and blades. Its powder-coated steel guards offer corrosion resistance suited to dusty or humid barn environments.

Designed for efficiency, the unit draws low amperage and emphasizes high airflow to distribute heat quickly. This style is appropriate when you need rapid warm-up and wide-area coverage, but it requires careful placement and ventilation planning to direct warmed air where animals or work activities need it most.

Mr. Heater 125,000 BTU Forced Air Propane Heater

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Mr. Heater’s 125,000 BTU forced-air unit focuses on high-output heating for large spaces. It features Quiet Burner Technology for reduced noise compared to standard forced-air heaters and includes a 10-foot hose and regulator for propane connection.

Built-in safety like a high-temperature limit switch helps protect the unit under heavy use. The forced-air approach is well-suited for barns requiring immediate heat and broad air movement. Consider mounting height and ducting or louvers to avoid directing hot air improperly toward animals or feed areas.

Mr. Heater Big Maxx MHU80NG LP Convertible Unit Heater

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The Mr. Heater Big Maxx comes configured for natural gas but includes a liquid propane conversion kit, making it adaptable to propane-fueled barns. It delivers 80,000 BTU and lists coverage up to about 2,000 square feet. The unit dimensions are 29.33” L x 15.50” W x 26.37” H and it operates on standard 120 V.

Note that thermostat, hose, and regulator are not included, and the product requires minimum clearances for safe operation. The unit supports category 1 vertical and category 3 horizontal venting options. This model suits barn owners who want a wall- or ceiling-mounted unit with conversion flexibility.

Mr. Heater Portable Buddy MH9BX Radiant Propane Heater

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The Portable Buddy is an infrared radiant heater offering adjustable output from 4,000 to 9,000 BTU. It’s rated for indoor-safe use in small, ventilated spaces up to roughly 225 sq. ft. making it useful for small tack rooms, individual stalls, or localized spot heating in barns.

Features include an improved tip-over safety switch, a Piezo igniter for matchless startup, and direct radiant heating that warms objects and people rather than air. As a portable solution, it requires a regulated LP connection and is best used where localized, temporary heat is adequate and where venting or permanent installation is impractical.

Buying Guide: How To Choose A Propane Barn Heater

Selecting the right heater involves balancing BTU output, heat type, safety features, and installation constraints. Below are the most important considerations and comparative perspectives to guide your decision.

1. Calculate Required BTU And Coverage

Estimate barn volume (square footage times average ceiling height) and desired temperature rise. Forced-air propane units with higher BTU and airflow are better for rapid heating of large volumes. Convection units work well for moderate-sized barns where steady ambient heat is sufficient. For spot heating of stalls or work areas, small radiant units provide focused warmth with lower fuel use.

2. Choose Heat Delivery Method: Forced-Air vs. Convection vs. Radiant

• Forced-Air: Fast warm-up and broad distribution. Best for large open barns but may require ducting, louvers, or directional louvers to avoid drafts and heat loss.
• Convection: Gentle, even heat that circulates naturally. Good for medium barns with decent insulation.
• Radiant: Heats objects and animals directly. Efficient for stall-level heating or small spaces but not for warming entire large barns.

3. Fuel Supply And Conversion Options

Confirm propane compatibility and tank size. Some units are designed for direct propane use; others are natural gas with an LP conversion kit. Conversion kits must be installed per manufacturer instructions and local codes. Consider whether you prefer connecting to a standard 20 lb tank or a larger bulk propane supply for extended run times.

4. Safety Features And Certifications

Look for CSA or similar safety certifications for certified construction and testing. Important safety features include overheat limit switches, tip-over protection for portable units, flame-failure devices, and proper venting or exhaust management for indoor use. Ensure minimum clearances and follow installation guidelines to minimize fire and CO risks.

5. Venting, Clearance, And Installation

Heater types differ in venting needs. Forced-air and some unit heaters may require combustion air and exhaust venting depending on category. Verify minimum clearances from combustible materials and floor level. Professional installation may be necessary for hardwired units or those requiring permanent venting.

6. Noise, Air Movement, And Animal Comfort

Forced-air systems create airflow and some noise; Quiet Burner or reduced-noise models may be preferable if animals are sensitive. Radiant units are quieter and do not create drafts, which can be important for livestock comfort and health.

7. Durability And Environmental Factors

Barn environments can be dusty, humid, or corrosive. Look for powder-coated guards, sealed motors, and corrosion-resistant components. Units with replaceable filters or accessible maintenance points will last longer in demanding conditions.

8. Cost Of Operation And Efficiency

Compare fuel consumption relative to BTU output and typical run-time. Forced-air units heat faster but may consume more fuel to maintain higher air temperatures. Radiant heaters can be more efficient for targeted heating due to lower heat loss to the environment.

9. Control Options And Thermostats

Some heaters accept external thermostats or include integrated controls. Thermostat compatibility allows better temperature management and fuel savings. Ensure any thermostat used is rated for the heater’s electrical and control signals.

10. Mobility And Use Case

Decide between portable units for temporary or seasonal use and permanently mounted units for continuous barn heating. Portable units are flexible but often lower capacity. Permanently installed units provide higher capacities and integration with fixed propane supplies.

Comparison Perspectives

• Large Barns/Warehouses: Favor 100k+ BTU forced-air heaters (e.g., 125,000 BTU models) for quick, wide-area heating and high airflow capability.
• Medium Barns/Workshops: 70k–90k BTU convection or unit heaters provide even background heat without high airflow disturbances.
• Small Stalls/Tack Rooms: Portable radiant heaters with 4k–9k BTU capacity are economical and targeted for localized comfort.
• Intermittent Use: Portable or smaller convection units on 20 lb tanks are convenient for seasonal operation.

When planning a propane barn heating solution, match the heater type and capacity to barn size, ventilation constraints, and the comfort needs of animals or workers. Always follow manufacturer installation instructions and local codes for safe operation.