High Efficiency Natural Gas Garage Heater

We’ve Revealed the High Efficiency Natural Gas Garage Heater!

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Blue Flame” natural gas garage heaters are the highest efficient models among all other gas heaters.

You might be familiar with four different natural gas space heaters,

  • Blue Flame (Example: Mr Heater MHVFB30NGT)
  • Radiant (Example: Mr. Heater F299831)
  • Forced Air (Torpedo) Models (Example: Dyna-Glo RMC-FA150NGDGD)
  • Vented Ceiling Mount Natural Gas Heater (Example: Big Maxx)

So, I’ll explain their efficiency level, step by step calculate the operational cost of each type from the same BTUs and scientifically explain why blue flame wins in terms of energy efficiency.

Additionally, you’ll get a chart of hourly operational costs for 52 different states of the United States.

Let’s dive in. 

Type of High Efficiency Natural Gas Garage Heater

1. Blue Flame (99.98% Efficient): 

These variants transfer heat with the CONVECTION mechanism. In other words, the blue flame raises air temperature, then your room/spaces or garage becomes hot through air circulation.

blue flame natural gas space heater

No catalytic plates or anything else comes in touch between the flame and the air, so the entire heat gets utilized, increasing room temperature. 

Then why it doesn’t provide 100% efficiency? Well, a few amounts of gas (0.015%) remain unburned, and the other 0.005% produces light, which is also a form of energy.

2. Radiant (97% Efficient): 

These models contain a radiator plate that consumes heat produced by burning gas. Then the radiant plate transmits heat as the infrared wave, so air or other mediums aren’t required for heat circulation.

Though it’s slightly inefficient compared to blue flame heaters, people prefer it more.

radiant natural gas space heater

Cause the heat directly penetrates surrounding objects, and unventilated spaces don’t cause an issue to keep yourself warm. 

But the radiant plate absorbs few energies, so the efficiency rate drops to 97%. Frankly, you even won’t be able to notice the operational cost difference between blue flame and radiant variant, so happily, you may pick it.

3. Forced Air or Torpedo (87% Efficient): 

With insane power, forced air models are a great solution to heat larger spaces like garages or workshops. They are crazy powerful but relatively low efficient considering the blue flame or radiant models. Thinking why?

natural gas torpedo heater

Forced air or torpedo, whatever you call it, contains a combustion chamber where compressed air gets mixed with the gas like a jet engine, then electric ignitor sparks to fire it up. As a result, the combustion mechanism forces more amount of gas to be burnt in smaller spaces. 

The increased rate of gas burning decreases the efficiency slightly.

As you’re watching the graphical structure, if you burn 0.01 MCF natural gas inside a one cubic meter compact place, it will produce 10K BTU each hour.

The BTU line climbs with increasing the amount of gas flow. But, at a particular stage, the BTU line starts tilting towards the horizontal axis. So the efficiency starts decreasing.

Thus, the forceful gas burn inside the torpedo combustion barrel decreases the efficiency though it boosts the performance.

4. Big Maxx Garage Heater (83% Efficient): 

If you aren’t familiar with Big MAXX, it’s a vented fan-forced natural gas garage heater, and only Mr. Heater does manufacture it.

These models are entirely vented with exhaust pipeline, and they’re as healthy as electric space heaters; cause there’s no chance of gas emission inside your rooms. That’s why people prefer these for garages.

But, the disadvantage regards their lower efficiency.

Big Maxx has a sealed heat exchanger, and gas fire blows forcefully inside it. So the heat exchanger gets hot, and a fan forcefully passes air through its surroundings, and your garage temperature starts rising by this circulation. 

Though this mechanism is excellent, a good amount of heat goes out through the exhaust line. As a result, the efficiency gets decreased. Mostly they provide around 83% ±3% cost efficiency, which isn’t that bad, though.

Why Blue Flames are the Highest Efficient Natural Gas Garage Heaters?

Before I explain this fact, you’ve to know the reason behind producing the blue flame. 

Fire color changes by temperature. Red flame produces the lowest temperature, and blue has the highest temperature. (orange, red, cherry, yellow, violate, etc., remains between them.)

Here’s the chart of fire color and their temperature

ColorTemperature °CTemperature °F
Blue Flame>1500°C>2732°F
White Flame>1400°C>2552°F
Yellow Flame>1100°C>2012°F
Orange Flame>950°C>1742°F
Cherry Red Flame>800°C>1472°F
Red Flame>600°C>1112°F

The gas nozzle contains an air vent. When the vent remains fully open and allows sufficient air to enter, gas burns with a blue flame. When the vent remains half-open, the fire color becomes violet. A slightly open vent creates a cherry flame, and a fully closed vent creates yellow light.

Here’s an image to demonstrate this fact.

Thus, blue flame heaters produce massive temperatures by burning natural gas with mixed air. However, there’s no obstacle between air and the flame in this convection procedure, as I’ve described above. So the system achieves an insane level of efficiency.

Specific Hourly operational Cost for 52 American States

We’ve calculated the hourly operational cost of Mr. Heater Blue Flame 30K BTU model based on all 52 American States.

Note: In max setup, the model consumes 0.030 MCF gas each hour. But you’ll find it far lower. Cause maintaining the room temperature, the thermostat will be on/off the unit several times, so it won’t remain ON throughout the hours.

Name Of StatePer MCF Cost30K BTU Blue Flame Hourly Cost
New Hampshire16.410.4923
New Jersey10.810.3243
New Mexico10.780.3234
New York14.920.4476
North Carolina16.50.495
North Dakota9.30.279
Rhode Island17.060.5118
South Carolina21.940.6582
South Dakota11.010.3303
West Virginia11.380.3414

How Clean the Efficient Natural Gas Garage Heaters Burn?

Natural gas is mainly 70% – 90% methane and a few amounts of ethene, propane, and butane. Here’s the chemical reaction that happens during you operate the blue flame heater.


CH4 + 2O2==> CO2 + 2H2O + [Energy]


2 C2H6(g) + 7 O2(g) ==> 4 CO2(g) + 6 H2O(g) + [Energy]


C3H8(g)+5O2(g) ==>3CO2(g)+4H2O(g) + [Energy]


2 C4H10 + 13.5 O2 ==>4 CO2 + 5H2O + [Energy]

From the equation we get, if you burn natural gas with sufficient air (mainly oxygen) or in any well-ventilated place that only produces carbon dioxide, which is exactly the gas we breathe out. 

So, burning natural gas is undoubtedly clean in this scenario. But, you have to be careful about sufficient ventilation. 

Well, ventilation allows the gas to be burnt clean and enhances the efficiency level multiple times.

Lack of air causes toxic gas production such as carbon monoxide, and the flame goes yellow. Obviously, then the BTU production decreases, and the efficiency level drops to 60%.

Finally, the ethical definition of energy efficiency that most people hardly understand.

People have a misconception about energy efficiency; that sounds like “the lower the operation cost, the higher the efficiency.” 

Energy efficiency represents producing more output (heat, mechanical activities) using the same amount of resources.

For example, if the 

HEATER X produces 30K BTU per hour utilizing 0.03 MCF gas

HEATER Y produces 29K BTU hourly by consuming 0.03 MCF gas

HEATER X will be considered more energy efficient than HEATER Y. 

People sometimes say natural gas heater is more efficient than kerosene, which isn’t always true. Yes, comparatively, natural gas costs less than kerosene, so the operational cost is relatively low. But that doesn’t have a relation with efficiency.