Overview: This guide compares five gas-powered heaters suitable for garage, workshop, or light industrial ceiling mounting. Below is a quick summary to help narrow choices by heat output, fuel type, and mounting style.
| Product | BTU | Fuel Type | Mount Type |
|---|---|---|---|
| Reznor UDXC-45 | 45,000 | Natural Gas | Ceiling Mount / Hanging |
| Reznor UDXC-60 | 60,000 | Propane (LP) | Ceiling Mount / Hanging |
| Mr. Heater Big Maxx MHU80NG | 80,000 | Natural Gas | Unit Heater (Ceiling/Walls With Brackets) |
| Mr. Heater MH40NG | 40,000 | Natural Gas | Infrared / High-Ceiling Mount |
| Dyna-Glo IR30NMDG-1 | 30,000 | Natural Gas | Wall/Infrared Mount (Suitable For Garages) |
Reznor UDXC-45 45,000 BTU Natural Gas Heater
Key Features: Indoor natural gas heater designed for garages, workshops, warehouses, and similar spaces. Rated at 45,000 BTU with two heat output levels (low fire 26,145 BTU, high fire 37,350 BTU claimed), and an 83% thermal efficiency. Offers threaded-nut retainers at four suspension points for ceiling hanging; mounting brackets sold separately. Quiet forced-air design with a low static propeller fan for air distribution.
This unit is specified for indoor use and intended for ceiling or suspended installation where permitted. The dual fire settings provide flexibility for milder and colder conditions. The listed 83% efficiency indicates a sealed combustion design and reasonable fuel-to-heat conversion for this class of shop heaters.
Reznor UDXC-60 60,000 BTU Propane Heater
Key Features: Propane-fueled indoor gas heater rated at 60,000 BTU with two output levels (low fire 34,860 BTU, high fire 49,800 BTU) and an 83% thermal efficiency. Designed for mounting from four suspension points; mounting hardware sold separately. Quiet forced-air operation with a low static propeller fan is intended to move warm air across larger spaces.
This model is engineered for propane-fueled environments where LP is the available fuel source. The dual-output capability offers staged heating for variable conditions. The product listing emphasizes ceiling mount flexibility and use in commercial or residential workshop spaces where venting and local codes permit indoor LP appliance operation.
Mr. Heater Big Maxx MHU80NG 80,000 BTU Unit Heater
Key Features: Natural gas unit heater with 80,000 BTU performance. Includes two angle brackets and an LP conversion kit. Heater dimensions and electrical specs are listed as 29.33” L x 15.50” W x 26.37” H, 120 V operation, and 2.3 amps. Coverage is cited for up to 2,000 sq. ft.; minimum 8-foot clearance from floor to base of unit is recommended.
The unit supports vertical category 1 venting and horizontal category 3 venting when required. The package mentions that thermostats, hoses, and regulators are not included, and the heater is presented as a commercial-style unit heater adaptable to ceiling or wall installations using provided brackets or optional suspension methods.
Mr. Heater MH40NG 40,000 BTU Infrared Garage Heater
Key Features: Infrared-style natural gas heater delivering 40,000 BTU with efficient radiant heat. Designed for buildings with 12 to 15 ft ceilings. Lists required clearances: Top 36″, Sides & Back 30″, Below 68″. Described as providing cost-effective infrared heat for garages and similar spaces.
Infrared heaters of this design heat objects and people directly rather than primarily warming the air, which can be advantageous in high-ceiling or intermittently occupied spaces. Clearance specifications should be followed for safe installation, and mounting type favors elevated placement compatible with high-ceiling workshop use.
Dyna-Glo IR30NMDG-1 30,000 BTU Infrared Wall Heater
Key Features: Natural gas infrared heater with up to 30,000 BTU output, rated to heat up to approximately 1,000 sq. ft. Uses infrared technology to radiate heat to objects before warming air. The unit is listed as “Natural Gas Ready” with no fuel conversion permitted.
This product is suited to wall-mount applications in garages and shops where radiant heat and rapid localized warmth are desired. Infrared wall units have different distribution characteristics compared to forced-air ceiling heaters; they may be preferable for spot heating or when air mixing is not desired.
Buying Guide: How To Choose A Gas Ceiling Heater
Selecting the right gas ceiling heater requires matching heater type, capacity, fuel, and installation constraints to your space and usage patterns. Below are the primary considerations with multiple comparison perspectives to clarify trade-offs.
Heat Output And Sizing (BTU)
BTU capacity indicates the maximum heat output per hour. Calculate required BTUs using room volume, insulation, and desired temperature rise. A rough starting point for a garage is 30–60 BTU per square foot depending on insulation and climate, but exact needs depend on ceiling height, doors, and air infiltration.
Consider multiple units for very large or irregular spaces to improve distribution rather than relying on a single high-BTU unit. Infrared units (radiant) can feel warmer at lower air temperatures because they heat objects directly, which may allow lower BTU selection for spot heating.
Fuel Type: Natural Gas vs Propane vs Ventless
Natural Gas is common for fixed installations with utility access. Propane (LP) is used where gas mains are unavailable. Some models are dedicated to one fuel, and others include conversion kits; check the manufacturer’s specifications and local code restrictions.
Vented vs Ventless: Vented (direct-vent or power-vented) unit heaters expel combustion products outdoors and are typically preferred for indoor garages and shops. Ventless (blue flame) units release combustion products into the space and are subject to strict local codes and oxygen depletion safety features—often less suitable for tightly sealed or continuously occupied spaces.
Heater Type: Forced-Air Unit Vs Infrared (Radiant)
- Forced-Air Unit Heaters (propeller or blower): Move warm air through a space and mix air; suitable for whole-space heating and spaces with moderate ceilings. Good for heating air for uniform temperature.
- Infrared/Radiant Heaters: Heat objects and people directly; perform well in high-ceiling areas or for spot heating. They typically produce quicker perceived warmth but may not change ambient air temperature as uniformly.
Mounting, Clearances, And Ceiling Height
Ceiling-mounted unit heaters often require suspension hardware and specific clearances from combustible materials, walls, and floors. Infrared models list minimum clearances to maintain safety. For high ceilings, radiant or high-output forced-air units rated for greater throw are more effective.
Verify mounting methods—some units include brackets; others require separate suspension kits. Obstructions like rafters, light fixtures, and door tracks impact airflow and heat distribution, so plan placement accordingly.
Efficiency And Combustion Safety
Thermal efficiency metrics (e.g., 83%) express how effectively fuel converts to heat. Higher efficiency reduces fuel consumption for comparable output. Also confirm safety features such as sealed combustion, pressure regulators, pilot safety, and oxygen depletion sensors (ODS) where applicable.
Direct-vent designs draw outside air for combustion and exhaust outdoors, improving indoor air quality compared to non-vented options. Check listed certifications and compliance with local mechanical codes.
Venting And Installation Requirements
Some heaters require vertical or horizontal venting categories; others are direct-vent or use induced draft exhaust. Venting constraints can determine whether a unit is practical for your building. Installation typically requires a licensed technician, gas line sizing, and sometimes electrical hookup for controls or blowers.
Confirm clearances, vent termination locations, and compliance with local codes before purchase. Permits or inspections may be necessary for new gas appliance installations.
Controls, Thermostats, And Modulation
Consider whether the heater supports a remote thermostat, integrated controls, or multi-stage firing. Units with low/high fire settings or modulating control provide better temperature regulation and can reduce cycling and fuel use. Some industrial units only offer manual or basic heat selection, while others integrate with building thermostats.
Noise, Airflow, And Distribution
Forced-air units rely on fans; fan speed and noise affect comfort in occupied spaces. Look for specifications referencing low-static fans or quiet operation if noise sensitive. Also evaluate recommended mounting height and heater orientation to ensure adequate warm-air throw across workspace.
Durability, Corrosion Resistance, And Maintenance
Shop and garage environments may expose heaters to dust, corrosive aerosols, or high humidity. Choose units with protective finishes, accessible filters, and serviceable parts. Regular maintenance tasks include burner inspection, filter cleaning (if applicable), and vent checks.
Regulatory And Safety Compliance
Verify that units meet ANSI or other regional standards and that installation complies with local building and mechanical codes. Gas appliance placement in attached garages, near flammable storage, or in living spaces can be restricted. Confirm any necessary clearances around doors and windows.
Comparing Multiple Perspectives
- Cost-Efficiency Perspective: Higher efficiency units and staged firing reduce fuel usage but may cost more up front. Balance initial cost, installation complexity, and operating fuel availability.
- Comfort Perspective: Forced-air models provide more uniform air temperature; radiant models offer faster localized warmth. Select based on typical occupancy patterns and ceiling heights.
- Installation Perspective: Units that require venting or specific clearances may need more complex installation. Simple wall-mounted radiant units can be easier but may not suffice for whole-room heating.
- Safety Perspective: Prioritize sealed-combustion or direct-vent units in enclosed spaces. Avoid ventless appliances for continuous occupancy unless codes permit and safety features are robust.
Final Practical Checks Before Purchase
- Confirm available fuel type and any conversion kit limitations.
- Measure ceiling height and plan heater placement for optimal distribution.
- Verify venting options and clearance specifications on the product sheet.
- Plan for professional installation, gas line sizing, and local permits if required.
- Check availability of replacement parts, filters, and service support for the chosen brand.