Choosing The Right Gas Heater For Your Garage means balancing heating power, venting type, installation, and safety. Below is a quick summary of the five gas heaters reviewed in this article to help you compare key specs at a glance.
| Product | Type | BTU | Coverage/Notes |
|---|---|---|---|
| Mr. Heater Big Maxx MHU80NG | Natural Gas Unit Heater | 80,000 BTU | Up To 2,000 Sq. Ft., Conversion Kit Included |
| Modine Hot Dawg HD45AS0111 | Natural Gas Unit Heater | 45,000 BTU | Residential/Commercial Certified, Low Profile |
| Dyna-Glo IR30NMDG-1 | Infrared Wall Heater | 30,000 BTU | Infrared Radiant Heat, Up To 1,000 Sq. Ft. |
| Reznor UDXC-45 | Natural Gas Unit Heater (Indoor) | 45,000 BTU | Ceiling Mount, 83% Thermal Efficiency |
| ProCom MN300TBA-B | Ventless Blue Flame | 30,000 BTU | Thermostat Control, Wall Or Floor Mount |
Mr. Heater Big Maxx MHU80NG Natural Gas Unit Heater
Overview: The Mr. Heater Big Maxx MHU80NG is a high-capacity natural gas unit designed for large garages and workshops. It delivers 80,000 BTU and is rated to cover up to 2,000 sq. ft.
Key Features: Unit includes two angle brackets and a liquid propane conversion kit. Thermostat, hose, and regulator are not included. Electrical specs: 120 V, 2.3 amps. Clearance requirement: minimum 8 ft. from floor to base of unit. Compatible with category 1 vertical and category 3 horizontal venting.
Who It’s For: Suitable for homeowners or small commercial operators needing robust heat output and flexibility for venting orientation. The included conversion kit provides adaptability if fuel source changes.
Modine HD45AS0111 Natural Gas Hot Dawg Garage Heater
Overview: The Modine Hot Dawg HD45AS0111 is a compact natural gas heater rated at 45,000 BTU. It is designed for residential, commercial, and industrial settings and emphasizes quiet operation and a low profile.
Key Features: Certified across multiple use categories, this Hot Dawg model features quiet operation and neutral finish for unobtrusive installation. Its low profile design fits in tighter garage spaces and can be mounted as required for optimal heat distribution.
Who It’s For: Garages where noise level, compact installation footprint, and certified multi-use operation are priorities. Suitable for homeowners wanting a proven bracket-mounted unit with a discreet appearance.
Dyna-Glo IR30NMDG-1 30,000 BTU Infrared Wall Heater
Overview: The Dyna-Glo IR30NMDG-1 is a natural gas infrared wall heater providing up to 30,000 BTU. It uses radiant heating to warm objects and people directly rather than only heating air.
Key Features: Designed for natural gas only (fuel conversion not permitted). Infrared technology radiates heat to surfaces and occupants, improving perceived warmth at lower air temperatures. Rated to heat up to 1,000 sq. ft.
Who It’s For: Garages and workshops where targeted, quick radiant heat is preferred over forced-air circulation. Infrared units can be effective in spaces with high ceilings or intermittent occupancy.
Reznor UDXC-45 Natural Gas Unit Indoor Garage Heater
Overview: The Reznor UDXC-45 indoor gas heater is built for garage, workshop, and light industrial spaces. It offers two heat output levels with high thermal efficiency.
Key Features: Rated output with selectable low and high fire settings (low fire 26,145 BTU / high fire 37,350 BTU per listing) and an 83% thermal efficiency rating. Ceiling mountable with threaded-nut suspension points. Designed for indoor use with quiet forced-air operation and a low static propeller fan.
Who It’s For: Users needing controlled heat levels and energy-efficient operation. Ceiling mounting frees floor space and delivers widespread forced-air warmth suitable for medium-size garages and shops.
ProCom MN300TBA-B Ventless Natural Gas Blue Flame Heater
Overview: The ProCom MN300TBA-B is a ventless blue flame natural gas heater rated at 30,000 BTU. It is intended for direct indoor space heating and includes thermostat control.
Key Features: Produces up to 30,000 BTU and claims coverage up to 1,400 sq. ft. Includes high/medium/low thermostat control and comes with wall mount and base feet for flexible placement. Slim profile for unobtrusive installation.
Who It’s For: Home garages or attached workshops where venting is limited or where a compact, wall-mounted ventless option is preferred. Note that ventless operation requires attention to ventilation and local codes.
Buying Guide: How To Choose The Best Gas Heater For Your Garage
Heat Output (BTU) And Space Size: Match the heater’s BTU rating to the garage volume, not just square footage. Higher ceilings increase volume and may require a higher BTU unit. Use BTU as a guideline: small garages often need 20k–40k BTU, medium 40k–80k BTU, and larger or poorly insulated spaces may need 80k or more.
Heating Method: Choose between forced-air (unit heaters like Modine/Reznor), infrared/radiant (Dyna-Glo), and ventless blue flame (ProCom). Forced-air distributes warmed air; infrared warms objects directly; ventless releases combustion products into the room and relies on room ventilation.
Fuel Type And Conversion: Confirm whether the unit is natural gas or propane. Some models include conversion kits (e.g., Mr. Heater includes an LP conversion kit). Conversion may require specific kits and professional adjustments. Verify compatibility and whether fuel conversion is permitted by the manufacturer.
Venting And Installation: Determine if your garage allows for direct venting (sealed combustion) or requires ventless operation. Unit heaters often require venting (category 1 or 3 configurations) or dedicated flue runs. Ceiling-mount units need proper suspension points; wall-mounted units need clearance and secure mounting.
Efficiency And Operating Modes: Look at thermal efficiency (%) and multi-stage firing. Higher efficiency reduces fuel usage. Multi-stage or modulating units can improve comfort and reduce cycling, which saves energy in variable-temperature environments.
Clearances, Mounting, And Space Constraints: Check manufacturer minimum clearances from walls, ceilings, and floors. Ceiling-mounted units like Reznor free floor space but need secure mounts. Low-profile models like Modine work well where headroom is limited.
Safety Features And Codes: Verify features such as sealed combustion, safety pilot, pressure regulators, and oxygen depletion sensors on ventless units. Ensure compliance with local building codes, particularly for ventless appliances and installations in attached garages.
Noise And Fan Type: For attached garages or workshops, noise can matter. Infrared heaters are typically quieter because they don’t rely on large fans. Forced-air units have fans and blowers; check product specs for noise expectations.
Maintenance And Serviceability: Consider ease of access for pilot and burner maintenance, availability of replacement parts, and local technician familiarity with the brand. Longer service life and ease of repair improve long-term value.
Thermostat And Controls: Integrated thermostats or compatibility with external thermostats improve comfort control and reduce fuel usage. Some units include multi-speed or stage controls for more precise temperature regulation.
Installation Costs And Professional Installation: Gas heater installation often requires a licensed plumber or HVAC technician for gas line connection, venting, and safety compliance. Factor installation, permits, and any structural modifications into your total cost assessment.
Comparison Perspectives: Evaluate based on output vs. efficiency (BTU per square foot vs. thermal efficiency), vented vs. ventless health and safety trade-offs, and installation complexity vs. operational convenience. For example, high-BTU vented units suit large, detached garages, while infrared works well for targeted heat in intermittently used spaces. Ventless units offer easy installation but may be restricted by code and indoor air quality concerns.