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A Guide to Natural Gas Garage Heaters

natural gas garage heater

The garage is one of the few areas of the house that is not as well-insulated as the rest of the home. Garage heating may be important if you have a workshop, storage space, or simply want a more comfortable environment when getting into and out of your vehicle.

In this article, we explore natural gas garage heaters, and what to look for when choosing one for your garage.

What is a Natural Gas Garage Heater?

As the name suggests, garage heaters are heating devices specifically designed to warm your indoor garage. 

There are three power sources for garage heaters: electric, propane and natural gas. 

Natural gas garage heaters are fueled by natural gas, a clean-burning fossil fuel that is piped into homes. These garage heaters are designed to efficiently convert natural gas into heat, providing warmth to the designated space.

The Different Types of Natural Gas Garage Heaters

Vented heaters

Vented gas heaters can heat spaces from 300 square feet to 3000+ square feet. While they tend to cost more, they are often a one-and-done solution. They come in different mounting models such as wall or space heaters.

Ventless heaters

As the name suggests, ventless or vent-free heaters don’t need a vent to the outside. They can usually service about 200 to 1000 square feet of space, with the option of choosing between blue flame and infrared or radiant heat

Blue flame

A blue flame heater functions by ultimately warming the air in the room where it is installed. Ideal for insulated spaces, blue flame heaters may take slightly longer to heat the entire space. These economical units typically operate around 99.9% efficiency. They can use a blower to help spread the warm air throughout the space and heat it up more quickly and evenly.

Infrared or Radiant

In contrast to blue flame heaters, infrared heaters use electromagnetic radiation to heat objects in the garage. The heat is directly transferred to surrounding objects, allowing for quicker warmth. However, they require additional safety precautions. Nearby items and stored boxes in the garage need to have a safe distance from the heater itself, especially in the case of a malfunction.

What are the Benefits of a Natural Gas Garage Heater?

✓ Cost-effective

Natural gas tends to be cheaper than propane and electricity in many areas. This makes NG heaters more cost-effective in the long run, especially if you have access to a reliable natural gas supply.

✓ Efficient

Natural gas garage heaters are more efficient than many electric heaters, meaning they can produce more heat with less energy input. This equates to lower energy bills compared to electric heaters.

✓ Convenient

Natural gas heaters are typically connected directly to a gas line, doing away with propane tanks or nearby power outlets. This can be more convenient, especially if you have access to a natural gas line.

✓ Environmental impact

While natural gas is a fossil fuel and does produce carbon emissions when burned, it generally produces fewer emissions compared to propane. Natural gas is also  considered cleaner than electricity generated from fossil fuels. Additionally, advancements in natural gas technology, such as condensing heaters, can further reduce such emissions.

✓ Reliability

Natural gas garage heaters are often considered more reliable than electric heaters, especially in areas prone to power outages. As long as you have a steady supply of natural gas, someheaters can operate even during power disruptions.

✓ Heat output

Natural gas heaters typically provide high heat output, making them suitable for larger garage spaces or areas that require rapid heating.

Propane and natural gas garage heaters are very cost-efficient, but require more space and maintenance. Electric garage heaters are less efficient, but come in a compact size and require less cleaning and maintenance.

What are the Drawbacks of Natural Gas Garage Heaters?

Carbon monoxide production

Natural gas garage heaters produce carbon monoxide (CO) as a byproduct of combustion, which can be hazardous in enclosed spaces. Installing CO detectors in the garage and adjacent living areas is essential for early detection of CO leaks. It is also important to have the unit professionally installed to insure proper venting if required by the heater. 

Fire safety

Proper installation, maintenance, and operation of natural gas garage heaters are crucial for preventing fire hazards. Keep flammable materials away from the heater, maintain clearances as per manufacturer instructions, and avoid using the heater for drying clothes or other purposes.

Area restrictions

Vent-free gas garage heaters are not legal in some states such as California. Check what type of garage heater is allowed in your local area. Always check your local codes when searching for a heating product.

When Should I Use a Natural Gas Garage Heater?

Natural gas garage heaters are ideal for:

  • Larger garages
  • Garages with a higher ceiling over the standard 8-foot height
  • Homes with a natural gas service
  • Colder climates

Choosing a Natural Gas Garage Heater

Here’s what to consider when choosing a natural gas garage heater for your home:

  1. Heating capacity

Natural gas garage heaters typically range from 10,000 to 400,000 BTUs. To determine the BTU capacity needed for your garage space, contact us for assistance.

  1. Efficiency

Natural gas garage heaters come with energy efficiency ratings that indicate their performance and fuel utilization efficiency.

These are measured by:

Annual Fuel Utilization Efficiency (AFUE):

AFUE represents the efficiency of a heating appliance in converting fuel to energy over the course of a typical year. It is expressed as a percentage and takes into account factors such as heat loss through the chimney and other inefficiencies in the heating process. The higher the AFUE ratings, the more efficient the gas heater is.

Thermal Efficiency:

Thermal efficiency measures how effectively a heater converts the energy in the fuel to usable heat. It is also expressed as a percentage and accounts for losses in the combustion process and heat distribution. Like AFUE, higher thermal efficiency ratings equate to better performance.

In general, modern gas garage heaters are more efficient than older models. High-efficiency models can have AFUE ratings ranging from 80% to over 95%. Similarly, thermal efficiency ratings may range from 70% to 90% or higher.

  1. Safety

Look for these safety features in a gas garage heater:

Overheating protection – ensures the heater doesn’t burn itself out, by using a sensor to detect dangerous temperatures.

Auto shutoff – this automatically switches the unit off in case the heater gets knocked over (applicable only to portable models) or suffers a short in the system.

Cool-touch exterior – typically found in portable and wall-mounted garage heaters. The heater body is made of fiberglass or plastic, making it safe to touch even during extended operation.

  1. Programmable thermostat

This allows the user to set a specific temperature via controler or electronic keypad. This makes the heater more efficient by only activating to maintain the desired temperature instead of working full-blast all the time.

  1. Oscillating vents

If you have a larger garage, oscillating louvers change the direction of the heat flow and help distribute the heated air more evenly across the space. Such louvers are usually capable of up to 180 degrees of rotation.

Installing a Gas Garage Heater

☑ Location

Both propane and natural gas garage heaters follow the same installation process. Start by choosing a location for the heater. Ideally, it should be placed where the heater’s fan can counteract the most heat loss in the garage. This way it’s able to warm the whole garage space more evenly.

Since heat rises, the thermostat should be placed about 4-5 feet off the ground to provide the most accurate reading.

☑ Gas supply

Next, choose the proper gas pipe, connection, and joint compounds. As you lay down pipe, ensure the connections are secure, and not placed where foot traffic or household objects stored in the garage may dislodge or damage the piping.

☑ Power

Some heaters will require power while others do not. If the heater has a fan or blower it will need power. Be sure to check the specifications of the heater you are considering to see its power requirements. Ventilation

Proper ventilation is crucial when installing a natural gas garage heater to ensure the safe combustion of fuel and the release of combustion byproducts. Ventilation requirements vary depending on the heater type and local building codes.

Maintenance & Care of Your Gas Garage Heater

Follow this checklist to ensure smooth operation of your gas garage heater year-round.

Regular Inspections

Routine inspections of the heater can help identify and address potential issues before they escalate. This should be conducted at least once a year by a qualified technician. The inspection should include:

  • Burner
  • Igniter
  • Thermostat
  • Ventilation system


Over time dust and debris can accumulate and affect the heater’s performance. They can also be a fire risk. Regular cleaning of the heater components, including the burner assembly and ventilation ducts for vented garage heaters, is essential for safe and efficient operation.

Our Recommended Gas Garage Heaters

Budget gas garage heater:

HearthRite HRW18MN 18000 BTU Infrared/Radiant Vent Free Gas Heater – Natural Gas

The Hearthrite vent-free heater uses radiant or infrared energy to warm up the garage. As a ventless heater, it is 99.9% efficient, and capable of up to 18,000 BTUs of heat.

It includes an Oxygen Depletion Sensor (ODS) that will shut off the heater if the oxygen levels drop to an unsafe level. Standard installation is wall mounting, but an optional floor stand and blower are each available separately. Other optional features are a blower for circulating the warm air throughout the space, and thermostatic controls (available with model HRW18TN).

Professional installation by a certified gas technician is required. Note that this vent-free heater cannot be shipped to California.

HearthRite HRW18MN 18000 BTU Infrared/Radiant Vent Free Gas Heater - Natural Gas
Price: $372.00 HearthRite HRW18MN 18000 BTU Infrared/Radiant Vent Free Gas Heater - Natural Gas

The Hearthrite vent free heater with 18,000 BTUs will warm up your room like sun coming in from a window. A radiant or infrared heater adds warmth to the room a...

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Vented gas garage heater:

Reznor UDX-60 60,000 BTU Power Vented Gas Fired Unit Heater

Offering an industry leading 82% thermal efficiency and a variety of different BTUs, the UDX series of heaters offer exceptional heat performance for areas both large and small. The UDX60 with 60,000 BTUs is ideal for medium spaces.

Features include Reznor’s patented TCore² titanium stabilized aluminized steel heat exchanger, as well as the  “G” terminal to the strip and a newly designed circuit board, which allows for fan-only operation without adding relays. 

Outwardly, Reznor has developed a sleeker design that shows no front or bottom hardware. The newly designed cabinet has external status indicating LED lights, a hinged door for easy access to the control panel and a removable front face.

DISCONTINUEDReznor UDX-60 60,000 BTU Power Vented Gas Fired Unit Heater
Price: $1,229.00 DISCONTINUEDReznor UDX-60 60,000 BTU Power Vented Gas Fired Unit Heater

For a long time Reznor has been providing the best heaters for a variety of applications. Reznor has improved their already industry leading technologies with...

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Ventless gas garage heater:

Rinnai FC824 24,000 BTU Vent Free Fan Convector Gas Heater

This vent-free garage heater uses a convection fan that helps to evenly distribute the 22,000 BTUs of warmth throughout your garage. It features modulating technology which includes a modulating gas valve and variable speed blower. This allows the furnace to use only the exact amount of gas needed to produce the heat required for the space. 

Because it is a ventless heater, it does not need to be installed near an exterior wall – you just need to have the gas line located appropriately. Of course you also need to have the appropriate minimum clearances – which are 2 inches all around (top, back and sides) and 30 inches in front of the heater. Another advantage of being vent free is the fact that there is virtually no heat loss with this heater. It provides approximately 99.9% efficiency making it one of the most fuel efficient heating products on the market. It is also extremely quiet, generating just 44dB / 30dB (H/L) of noise levels.

Safety features include a cool-touch exterior, oxygen depletion sensor, overheat switch, tilt and knock sensors, and auto shutoff in the event of power failure.

Rinnai FC824 24,000 BTU Vent Free Fan Convector Gas Heater - Choice of Fuel Type
Price: $1,026.00 Rinnai FC824 24,000 BTU Vent Free Fan Convector Gas Heater - Choice of Fuel Type

You may only know of Rinnai for their tankless hot water heaters but they also have an extremely efficient line of vent free fan convector gas heaters. The FC82...

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Premium gas garage heater:

Sterling HU050A1NS111 Nexus Series 50,000 BTU Gas Fired High Efficiency Condensing Unit Heater

Sterling’s Nexus series boasts the highest efficiency ratings in the unit heater industry, offering ratings from 95% up to 99% efficient. This particular model offers 97% efficiency with its 50,000 BTU input and 48,600 BTU output. 

The heater features a unique tri-metal heat exchanger as well as a state of the art combustion control system. The heat exchanger is constructed of a hybrid combination of stainless steel tubes and brass and aluminum fins for maximum efficiency, enhanced corrosion protection and thermal heat transfer. In addition to the efficiency of these heaters, they include an auto-adjust altitude feature, which, as the name implies, is automatic. Requiring NO Field Adjustments, they automatically adjust the air and fuel mixture with no loss of performance. 

The Nexus Series heaters are field convertible to LP (single orifice kit included) and Separated Combustion operation. Additionally, they are PVC/CPVC vent compatible. Nexus unit heaters can be installed as single units or set up as a multi-unit network. The control board also includes ModBus communication for building automation without requiring additional control modules. 

The heater also comes with both indoor and outdoor air reset modulation. Indoor air reset learns the needs of the space by constant monitoring and modulates accordingly, resulting in less cycling and therefore lower fuel costs. Outdoor air reset functions in much the same manner, automatically adjusting and varying the indoor discharge air temperature based on the outdoor air temperature. Both of these functions offer your occupants a much more comfortable indoor environment while saving you money in the long run. 

Sterling HU050A1NS111 Nexus Series 50,000 BTU Gas Fired High Efficiency Condensing Unit Heater - Convertible Standard or Separated Combustion
Price: $3,369.00 Sterling HU050A1NS111 Nexus Series 50,000 BTU Gas Fired High Efficiency Condensing Unit Heater - Convertible Standard or Separated Combustion

The Sterling HU050A1NS111 is the smallest unit in the NEXUS Series. It offers 97% efficiency rating with its 50,000 BTU input and 48,600 BTU output. The Nexus S...

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Mickey Luongo

Mickey is the resident heating and air conditioning expert with over 15 years of experience in the industry.

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