Selecting a compact natural gas heater for a garage requires balancing heat output, ventilation requirements, installation type, and footprint. Below is a concise comparison of five small-to-mid-size natural gas garage heaters well suited to garages, workshops, and small commercial spaces.
| Product | Type | BTU | Coverage |
|---|---|---|---|
| Mr. Heater Big Maxx MHU80NG | Unit Heater (Ceiling/Wall) | 80,000 BTU | Up To 2,000 Sq. Ft. (Manufacturer Spec) |
| Dyna-Glo IR30NMDG-1 | Infrared Wall Heater | 30,000 BTU | Up To 1,000 Sq. Ft. |
| Reznor UDXC-45 | Ceiling Mount Forced Air | 45,000 BTU | Small To Mid Garages / Shops |
| Modine Hot Dawg HD45 | Unit Heater (Low Profile) | 45,000 BTU | Residential/Commercial Use |
| Comfort Glow 17,000 BTU Wall Heater | Direct Vent Wall Heater | 17,000 BTU | Up To 570 Sq. Ft. |
Mr. Heater Big Maxx MHU80NG Natural Gas Unit Heater
This 80,000 BTU natural gas unit heater is a compact forced-air solution designed for garages and larger workshops. The unit ships with two angle brackets and an LP conversion kit, though thermostat, hose, and regulator are not included. Size dimensions are 29.33” L x 15.50” W x 26.37” H, with a manufacturer-stated coverage area up to 2,000 sq. ft.
Installation notes: Requires minimum 8 ft. clearance from floor to base and 120 V power for the blower (amps ~2.3). Venting is available as Category 1 vertical or Category 3 horizontal. This heater is suited for garage ceiling- or wall-mounting where a higher-capacity forced-air heater is needed.
Dyna-Glo IR30NMDG-1 30,000 BTU Natural Gas Infrared Wall Heater
The Dyna-Glo IR30NMDG-1 is a 30,000 BTU infrared wall heater that radiates heat to objects and people rather than only heating air. Infrared operation can feel faster in spot-heating scenarios and is useful when the garage door opens frequently.
Key points: The model is natural-gas-ready with no fuel conversion allowed. Coverage is listed up to 1,000 sq. ft. because infrared warms surfaces and occupants directly. Wall mounting minimizes floor space use, and the radiant approach can be more efficient for intermittent occupancy in a garage or workshop.
Reznor UDXC-45 45,000 BTU Natural Gas Garage Heater
The Reznor UDXC-45 is part of a commercial line offering quiet forced-air heating with a low-static propeller fan. Rated at 45,000 BTU, it supports two firing levels for milder or colder conditions (low fire ~26,145 BTU, high fire ~37,350 BTU as listed) and lists an 83% thermal efficiency.
Mounting flexibility: The unit includes threaded retainers for suspension from the ceiling. It is intended for indoor use in garages, shops, and small warehouses. The forced-air design delivers rapid mixing of warm air throughout the space compared with radiant-only heaters.
Modine Hot Dawg HD45 45,000 BTU Natural Gas Garage Heater
The Modine Hot Dawg HD45 is a 45,000 BTU unit designed for quiet operation with a low-profile form factor. It is certified for residential, commercial, and industrial use, making it a versatile option for attached garages and workshops.
Features to note: The unit emphasizes quiet operation and a neutral appearance that blends into garage ceilings or walls. Forced-air distribution makes it suitable for evenly heating enclosed garage spaces. Modine units often integrate into professional installations and are commonly used where consistent, durable unit heaters are preferred.
Comfort Glow 17,000 BTU Direct Vent Natural Gas Wall Heater
The Comfort Glow wall heater is a 17,000 BTU direct-vent model rated to heat up to 570 sq. ft. It uses a sealed combustion system and matchless piezo ignition. Safety features include a pressure regulator and a sealed burner to stop gas flow if the pilot goes out.
Application: This compact, space-saving wall-mounted heater is useful for smaller garages or as a supplemental zone heater inside attached garages. Because it is a vented unit, it keeps combustion products separate from indoor air, which is often desirable for garage ventilation and safety.
Buying Guide: Choosing A Small Natural Gas Garage Heater
Selecting the right small natural gas heater requires assessing space, ventilation, installation preferences, and usage patterns. Review the following key considerations before purchase.
1. Heat Output And Room Size
Match BTU capacity to garage volume and insulation level. As a rough guide: insulated two-car garages often need 30,000–60,000 BTU for full comfort, while smaller single-car garages may need 15,000–30,000 BTU. Manufacturer coverage estimates vary, so calculate cubic footage and account for cold climates or poor insulation.
2. Heater Type: Forced-Air, Infrared, Or Ventless/Direct Vent
- Forced-Air Unit Heaters: Good for even distribution; models like Mr. Heater, Reznor, and Modine use blowers to mix air. Require electrical power for the fan and adequate clearances.
- Infrared/Radiant Heaters: Radiate heat to objects and occupants; effective for spot heating and garages with frequent door openings. Dyna-Glo is an example.
- Direct Vent: Sealed combustion vents exhaust outdoors and keep combustion byproducts separate from indoor air — a safer choice for attached garages. Comfort Glow is a direct vent example.
3. Venting And Safety Requirements
Confirm venting category and clearances. Direct-vent and Category 1/3 venting options affect where you can locate the unit. Ventless units are typically not recommended for standard garages due to combustion byproducts and safety concerns unless specifically approved for the space.
4. Installation And Mounting
Decide between ceiling-mount, wall-mount, or floor/portable positions. Ceiling-mounted forced-air units free floor space and circulate heat effectively; wall-mounted radiant or direct-vent units save footprint. Verify mounting hardware, clearance from combustible materials, and if electrician or gas-line modifications are needed.
5. Fuel Conversion And Local Codes
Check whether the unit is natural-gas-ready or convertible to propane. Some models prohibit conversion. Always confirm local building and gas codes, including permits and inspections required for gas appliance installations.
6. Efficiency, Controls, And Accessories
Look for thermal efficiency ratings and available controls such as thermostats, multi-stage firing, or timers. Accessories like horizontal/vertical vent kits, hanging brackets, and conversion kits affect overall installation cost and flexibility.
7. Noise And Air Movement
Forced-air units include blowers that create noise and air circulation; infrared and direct-vent units can be quieter. Consider noise tolerance if the garage doubles as workspace or near living spaces.
8. Safety Features
Important features include sealed combustion, safety pilots, pressure regulators, and automatic shutoffs for flame failure. Direct venting reduces indoor combustion exposure; ensure carbon monoxide detection is present in attached homes.
9. Maintenance And Durability
Review serviceability: access to burners, filters (if any), and fan components. Commercial-grade units such as Reznor and Modine are designed for heavier duty and frequent use, while smaller wall units may require less maintenance but have different service needs.
10. Comparison Perspectives
- Small Footprint & Space-Saving: Wall-mounted direct-vent or radiant models like Comfort Glow or Dyna-Glo.
- Even Heat Distribution: Ceiling-mounted forced-air units like Mr. Heater, Reznor, or Modine.
- Intermittent Use / Spot Heating: Infrared radiant heaters that warm occupants and work zones quickly.
- Continuous Use & Commercial Duty: Reznor and Modine models offering higher durability and serviceability.
When choosing, compare BTU output, venting type, mounting options, safety features, and local code compliance. Professional installation is recommended for gas appliances to ensure proper ventilation, safe connections, and adherence to regulations.