Best Natural Gas Forced Air Heater for Garages and Workshops

Choosing the right natural gas forced air heater depends on space size, installation, efficiency, and venting options. This guide compares top-rated natural gas unit heaters suitable for garages, shops, warehouses, and job sites, with a quick summary and detailed review of each model to help match features to your needs.

Model	Type	BTU Range	Best For
Reznor UDXC-45	Ceiling/Wall Forced Air Unit	45,000	Small To Medium Garages/Workshops
Reznor UDXC-200	Ceiling Forced Air Unit	200,000	Large Warehouses/Commercial Spaces
Mr. Heater Big Maxx MHU80NG	Natural Gas Unit Heater	80,000	Medium Shops And Garages
L.B. White Tradesman 170N	Portable Forced Air Heater (Direct-Fired)	125,000–170,000	Construction Sites, Outdoor/Well-Ventilated Areas
Comfort Glow 25,000 Direct Vent Wall Heater	Direct Vent Wall Heater (Sealed Burn)	25,000	Small Rooms, Garage Wall Mount

Reznor 45,000 BTU Unit Natural Gas Heater Indoor Use Garage and Shop Heater | UDXC-45

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The Reznor UDXC-45 is a compact forced air natural gas unit heater designed for indoor commercial and residential spaces. It lists a nominal rating of 45,000 BTU with dual output levels (low and high fire) to match varying temperature requirements.

Key features from the product listing include an 83% thermal efficiency rating, two heat output settings (low fire: 26,145 BTU; high fire: 37,350 BTU as listed), and threaded-nut retainers at four suspension points for ceiling or wall mounting. The design emphasizes quiet operation using a low-static propeller fan, making it suitable for garages and workshops where noise is a concern.

Installation flexibility (ceiling mount or wall) and moderate BTU output make this model appropriate for small to medium spaces. Users should confirm required clearances and whether mounting brackets are included, as the product notes that mounting hardware may be sold separately.

Reznor 200,000 BTU Commercial Natural Gas Garage Heater Ceiling Mount | UDXC-200

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The Reznor UDXC-200 is a high-capacity forced air natural gas unit heater for large commercial or industrial spaces. It offers a significant output for heating warehouses, factories, and large shops.

Product features include a 200,000 BTU rating with dual output levels (low fire: 116,200 BTU; high fire: 166,000 BTU as specified), and an 83% thermal efficiency rating. Like other UDXC models, it provides multiple suspension points for ceiling mounting and is built for indoor applications. The listing also references a vertical Category 1 B-vent kit for venting considerations.

This unit is intended for large spaces where high heat load and robust airflow are required. Buyers should plan for professional installation, confirm venting requirements and clearances, and ensure structural support for ceiling mounting due to the unit’s size and weight.

Mr. Heater F260560 Big Maxx MHU80NG Natural Gas Unit Heater, 80,000 BTU

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The Mr. Heater Big Maxx MHU80NG is a compact natural gas unit heater rated at 80,000 BTU. The listing notes a coverage area up to 2,000 sq. ft. and provides hardware such as two angle brackets and a propane conversion kit (LP conversion kit included, though model is specified for natural gas).

Product specifications include dimensions, electrical requirements (120 V / 2.3 amps), and installation notes such as a minimum 8 ft clearance from the floor to the base of the unit. The heater supports Category 1 vertical or Category 3 horizontal venting configurations per the listing.

This model suits medium-sized garages and shops. The listing indicates that thermostat, hose, and regulator are not included, so buyers should plan for compatible controls and fuel connections when budgeting installation.

L.B. White Tradesman 170n Portable Forced Air Heater 125,000-170,000 BTUH

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The L.B. White Tradesman 170N is a high-output, portable direct-fired forced air natural gas heater offering 125,000–170,000 BTU/hr. It’s designed primarily for construction sites and well-ventilated or outdoor work areas.

Notable features in the product description include near 99.97% fuel efficiency due to direct-fired technology, reliable electronic spark ignition, and a built-in diagnostic light for troubleshooting. The unit is constructed with heavy-gauge combustion chamber materials and a protective tri-shield finish for durability in demanding environments.

As a portable, direct-fired heater, the Tradesman 170N provides maximum heat output but requires adequate ventilation because combustion products are exhausted into the heated space. This model fits scenarios where mobility, rugged construction, and high output are primary needs.

Comfort Glow 25,000 BTU Direct Vent Natural Gas Wall Heater, Gray, large

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The Comfort Glow 25,000 BTU unit is a direct vent wall heater with a sealed burn system designed to heat smaller spaces (listed coverage up to 825 sq. ft.). The sealed combustion design reduces indoor air exposure to combustion byproducts.

Product features include Matchless Piezo Ignition, a safety pilot with an internal pressure regulator to stop gas flow if the pilot extinguishes, and a compact wall-mount form factor. The unit emphasizes space-saving installation and safety in confined areas where direct venting can be run to the exterior.

This heater is suitable where venting to the outdoors is possible and a wall-mounted footprint is preferred. The sealed burn system supports indoor air quality considerations compared to direct-fired forced air units.

Buying Guide: How To Choose A Natural Gas Forced Air Heater

Selecting the right natural gas forced air heater requires evaluating the heating load, installation constraints, venting, efficiency, safety, and intended use case. Below are key considerations and comparative perspectives for informed decisions.

1. Heating Capacity And Space Size

• BTU Rating vs. Space: Estimate required BTUs based on square footage, ceiling height, insulation quality, and exposure. Small garages often need 25k–50k BTU; larger shops and warehouses may require 100k–200k BTU or more.
• Two-Stage Output: Models with low/high fire settings (like Reznor UDXC series) provide better modulation across seasons and can improve comfort and efficiency.

2. Forced Air vs. Direct-Fired vs. Infrared

• Forced Air Unit Heaters circulate warm air via fans; suitable for garages and enclosed shops where conditioned air distribution is desired.
• Direct-Fired (Open Combustion) heaters (e.g., portable L.B. White Tradesman) exhaust combustion products into the space and require well-ventilated areas; they deliver high BTU per fuel unit but may not be appropriate for enclosed occupied spaces.
• Infrared/Wall Heaters radiate heat to objects and people, useful for spot heating and smaller areas; direct-vent wall units maintain sealed combustion for better indoor air quality.

3. Venting And Combustion Safety

• Sealed Combustion/Direct Vent units draw combustion air from outside and vent exhaust outdoors; preferred when indoor air quality is a concern.
• Category 1 vs. Category 3 Venting: Check the unit’s venting category; some units support vertical or horizontal vent runs while others require specific B-vent kits.
• Clearances And Mounting: Ceiling-mounted units need structural support and minimum clearances. Confirm manufacturer clearance specs before installation.

4. Efficiency And Operating Costs

• Thermal Efficiency Rating: Higher efficiency (e.g., 83% noted for Reznor models) means more of the fuel’s energy becomes usable heat.
• Direct-Fired Efficiency can approach 100% in terms of fuel-to-heat conversion but may introduce ventilation and air exchange costs for indoor environments.

5. Installation, Controls, And Accessories

• Mounting Options: Ceiling vs. wall vs. portable — choose according to available space and structural capacity.
• Controls And Thermostats: Confirm whether thermostats, regulators, or control modules are included; many unit heaters require separate controls.
• Venting Kits And Brackets: Some listings note vent kits or mounting hardware sold separately; plan for these additional items.

6. Noise, Airflow, And Comfort

• Fan Type: Propeller fans and low-static designs reduce noise. Consider operating noise for spaces where people work nearby.
• Air Distribution: Larger units move more air and can distribute heat faster. For even temperatures, evaluate louvers or ducting options if applicable.

7. Durability And Application Environment

• Construction Quality: For job sites or industrial use, look for heavy-gauge chambers and protective coatings (e.g., tri-shield finishes).
• Portable vs. Fixed: Portables offer flexibility for temporary sites, while fixed ceiling/wall units provide continuous comfort for permanent spaces.

8. Safety Features And Codes

• Safety Pilots And Limit Switches: Features like safety pilots, pressure regulators, and high-temperature limit switches are important for safe operation.
• Local Codes And Permits: Verify compliance with local building codes, venting regulations, and fuel supply requirements; professional installation is often required.

Comparison Perspectives

• Small Enclosed Garage: Consider sealed direct-vent wall heaters (Comfort Glow 25k) or smaller forced-air ceiling units (Reznor UDXC-45) for indoor air quality and space-saving installation.
• Medium Shop (Single-Bay): Mid-range unit heaters like the Mr. Heater Big Maxx 80k offer balance between airflow, coverage, and mounting flexibility.
• Large Warehouse/Commercial: High-capacity ceiling units like the Reznor UDXC-200 deliver the BTU output and airflow needed for large volumes.
• Temporary Or Outdoor Job Sites: Portable direct-fired units such as the L.B. White Tradesman 170N provide maximum output and ruggedness but require ventilation planning.