Find Reliable Heating Solutions for garages, workshops, warehouses, and large indoor spaces with this selection of gas unit heaters. The table below summarizes key model types to help you compare coverage, fuel type, and notable features at a glance.
| Model | Fuel Type | BTU / Coverage | Notable Feature |
|---|---|---|---|
| Mr. Heater Big Maxx MHU80NG | Natural Gas | 80,000 BTU / ~2000 sq. ft. coverage | Category 1/3 venting options |
| Mr. Heater MHU80LP Propane Unit | Propane | 80,000 BTU / up to 1000 sq. ft. | Spark ignition with self-diagnostic module |
| Dyna-Glo IR30NMDG-1 | Natural Gas | 30,000 BTU / up to 1,000 sq. ft. | Infrared radiative heating |
| Modine Hot Dawg 75K | Propane | 75,000 BTU input | Power-vented, 80% efficiency |
| Mr. Heater Portable Buddy MH9BX | Propane | 4,000–9,000 BTU / up to 225 sq. ft. | Portable, indoor-safe radiant heater |
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Mr. Heater Big Maxx MHU80NG
Purpose-Built For Large Spaces: The Mr. Heater Big Maxx MHU80NG is designed as a fixed natural gas unit heater delivering 80,000 BTU. The manufacturer states coverage for approximately 2,000 sq. ft., making it suited for medium-to-large garages and workshops.
Included with purchase are two angle brackets and a liquid propane conversion kit. The unit requires separate thermostat, hose, and regulator if needed. Physical dimensions are 29.33” L x 15.50” W x 26.37” H and minimum clearance requirements include 8 ft. from floor to base.
Electrical specs list 120 V operation at around 2.3 amps. The unit supports category 1 vertical and category 3 horizontal venting, offering flexible vent configurations. Installation and venting requirements should be confirmed with a qualified installer and local codes.
Mr. Heater Propane Unit MHU80LP
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High Output Propane Option: The MHU80LP provides 80,000 BTU/hr and is targeted at users who prefer propane fuel. Mr. Heater indicates it can heat up to 1,000 square feet, with a spark ignition system and a self-diagnostic control module to simplify troubleshooting.
Mounting is simplified by the inclusion of two angle brackets for ceiling installation. This unit is often chosen where propane is the available or preferred fuel source. As with all gas heaters, proper clearance, venting (if applicable), and fuel supply considerations are essential for safe operation.
Dyna-Glo IR30NMDG-1 Infrared Wall Heater
Radiant Infrared Heating: The Dyna-Glo IR30NMDG-1 uses infrared technology that radiates heat to objects and people rather than primarily heating air. It delivers up to 30,000 BTU/hr and is rated to heat areas up to roughly 1,000 sq. ft.
This model is natural gas ready and does not permit fuel conversion per the product details. Infrared heaters can be efficient in spaces where targeted, direct warmth is preferred—especially in areas with high ceilings or where air circulation reduces convective heating effectiveness.
Modine Hot Dawg Propane Unit Heater
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Commercial-Grade Unit Heater: Modine’s Hot Dawg is a gas-fired unit heater offered for propane with a 75,000 BTU input and reported 80% efficiency. The unit is power-vented, an important installation detail where combustion ventilation must be managed.
Modine units are commonly specified for garages, service bays, and light commercial spaces. The power-venting and efficiency rating imply attention to venting route and blower integration; these should be verified with an HVAC professional for compatibility with your space.
Mr. Heater Portable Buddy MH9BX
Portable Indoor-Safe Radiant Heater: The MH9BX is a compact propane radiant heater offering 4,000 to 9,000 BTU and suitable for up to 225 sq. ft. It uses infrared radiant technology to heat objects directly and includes safety features such as an improved tip-over switch and a durable piezo igniter.
This model is useful for small workshops, garages, or supplemental localized heating where venting or a permanent gas connection is not practical. It operates on small propane cylinders and includes an automatic safety shutoff if tipped over.
Buying Guide: How To Choose A Gas Unit Heater
Fuel Type And Availability: Decide between natural gas and propane based on what fuel is accessible at your site. Natural gas typically offers a continuous supply through utility lines; propane requires tanks and periodic refills.
BTU Output And Coverage: Match the heater’s BTU rating to your space. Higher ceilings and poor insulation increase BTU requirements. Manufacturer coverage estimates provide starting points, but climate, insulation, and space layout should guide final selection.
Heating Method: Choose between forced-air unit heaters and infrared/radiant heaters. Forced-air units move warmed air and work well for whole-space heating. Infrared units warm objects directly and can feel warmer at lower air temperatures, useful for targeted heating and open bays.
Venting And Installation: Confirm venting requirements: power vented, category 1, or category 3 venting may be required depending on the model. Some units need vertical termination; others allow horizontal venting. Local codes and professional installation often apply.
Mounting And Placement: Ceiling-mounted units save floor space and distribute heat broadly. Wall-mounted infrared units focus radiant heat. Portable models offer flexibility but limited coverage. Consider minimum clearances and mounting hardware included with the unit.
Controls And Compatibility: Verify whether the unit supports external thermostats, onboard thermostats, or remote monitoring. Some models include self-diagnostic modules and spark ignition for easier start-up and troubleshooting.
Efficiency And Performance: Look at efficiency ratings and whether the unit cycles frequently. Higher efficiency reduces fuel consumption over time. Consider the unit’s stated amp and voltage requirements to ensure electrical compatibility.
Safety Features: Review built-in safety features such as tip-over shutoff (for portable heaters), flame failure protection, overheat limits, and certified safety listings. Proper clearances and CO detection are essential when using gas heaters indoors.
Space-Specific Considerations: For garages with vehicle exhaust or chemicals, ensure ventilation and combustion air are adequate. For workshops with intermittent use, instant-on radiant heaters may be preferable for spot heating rather than maintaining entire volume temperature.
Comparison Perspectives:
- Large Whole-Space Heating: Look for 70,000–80,000 BTU fixed units with proper venting and mounting. (Example: Mr. Heater MHU80 series, Modine Hot Dawg).
- Targeted Or High-Ceiling Areas: Consider infrared units that heat objects directly rather than air (Example: Dyna-Glo IR30NMDG-1).
- Portability And Flexibility: Choose portable, indoor-safe models for temporary or small-area heating (Example: Mr. Heater MH9BX).
- Installation Complexity: Power-vented or vented units often require professional installation and adherence to codes, while portable models need minimal setup.
Final Selection Tips: Measure the space, review local code requirements, confirm fuel availability, and consult an HVAC professional for vent sizing and installation safety. Prioritize units with clear venting specifications and appropriate safety certifications for indoor use.
Tips for Getting the Best HVAC Prices
- Prioritize Quality Over Cost
The most critical factor in any HVAC project is the quality of the installation. Don’t compromise on contractor expertise just to save money. - Check for Rebates
Always research current rebates and incentives — they can significantly reduce your overall cost. - Compare Multiple Quotes
Request at least three estimates before making your choice. You can click here to get three free quotes from local professionals. These quotes include available rebates and tax credits and automatically exclude unqualified contractors. - Negotiate Smartly
Once you've chosen a contractor, use the proven strategies from our guide — How Homeowners Can Negotiate with HVAC Dealers — to get the best possible final price.