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MTNG carries many different brands, sizes, and styles of both vented and unvented space heaters. Visit your local office and talk with our experienced sales staff about which space heater best meets your needs. All are sold at affordable, installed prices.
Advantages:
- Excellent back-up heat source during power outages--most units do not require electricity to operate.
- Natural convection action helps to provide even heat throughout room.
- Variety of sizes available to fit most applications.
- Moisture is added to household air in heated spaces.
- Vent-free models are available for many applications.
- Blowers are available to fit most models.
Gas Space Heat Required by Square Footage
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BTUs Required
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Square Feet
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200
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400
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600
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800
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Well Insulated
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6,400
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12,800
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19,200
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25,600
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Average
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10,000
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20,000
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30,000
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40,000
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Poorly Insulated
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12,800
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25,600
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38,400
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51,200
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BTUs Required
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Square Feet
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1,000
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1,200
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1,600
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2,000
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Well Insulated
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32,000
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38,400
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51,200
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64,000
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Average
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50,000
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60,000
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80,000
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100,000
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Poorly Insulated
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64,000
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76,800
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102,400
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128,000
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THIS TABLE IS FOR QUICK REFERENCE ONLY. EVERY APPLICATION IS
DIFFERENT AND THERE ARE MANY FACTORS TO CONSIDER.
Notes:
- This table does not distinguish between vented and unvented heaters.
- It utilizes formulas that have been used by Middle Tennessee Natural Gas employees.
- The "well insulated" rating is figured using 4 BTUs per cubic foot and a ceiling height of 8 feet.
- The "average" rating is figured using 50 BTUs per square foot.
- The "poorly insulated" rating is figured using 8 BTUs per cubic foot and a ceiling height of 8 feet.
Operating Cost Comparison:
Let's say that you have determined from the sizing table that you need 30,000 BTUs per hour to heat your space. In order to provide an output of 30,000 BTUs per hour, a vented gas space heater that is 75% efficient, for example, would need to be sized at 40,000 (40,000 x .75 = 30,000). A vent-free space heater that is 99.9% efficient would need to be sized at 30,030 BTUs per hour (30,030 x .999 = 30,000).
To find the properly sized electric heater, we must remember that 29.3 kWs are required to create 100,000 BTUs. Multiply 29.3 by .3 to get the number of kWs needed to provide 30,000 BTUs per hour. The answer is 8.79 kWh.
For this example, let's use a natural gas cost of $.70 per therm, a propane cost of $1.00 per gallon, and an electricity cost of $.07 per kW. The calculations to get 30,000 BTUs output would look like this: The answer is 8.79 kWh.
You can use the same method for calculating operating costs for any size and efficiency space heater.
- Natural Gas Vented
75% Efficient
- $.70 x 1 x 1.33=$.93 (for 100,000 BTUs output)
$.93 x .3 = $.28
- Natural Gas Vent-Free
99.9% Efficient
- $.70 x 1 x 1.00 = $.70 (for 100,000 BTUs output)
$.70 x .3 = $.21
- Propane Vented
75% Efficient
- $1.00 x 1.1 x 1.33 =$1.46 (for 100,000 BTUs output)
$1.46 x .3 = $.44
- Propane Vent-Free
99.9% Efficient
- $1.00 x 1.1 x 1.00 =$1.10 (for 100,000 BTUs output)
$1.10 x .3 = $.33
- Electric
- $.07 x 8.79 = $.62 (for 30,000 BTUs output)
Selecting a Space Heater:
Natural Convective Heaters:(Standard Vented Space Heaters)
Uses natural circulation created in the room to distribute heated air. As the air is warmed by the heater, it becomes lighter and naturally rises. The rising warm air displaces cooler air at the ceiling and forces it downward where it is heated and the cycle continues.
- Creates even warming throughout the room.
- Can be thermostatically controlled (optional) to automatically maintain comfortable room temperatures.
- No electricity required.
Forced Convective Heaters:(Standard Vented Space Heater with Blower)
Similar to natural convective heaters but with the addition of an electric blower to help with the movement of heated air.
- Creates even warming throughout the room.
- Can be thermostatically controlled (optional) to automatically maintain comfortable room temperatures.
- Requires electricity to operate the blower. Some blowers are thermo-statically controlled so that they only operate when temperatures surrounding the heater require additional air circulation.
Radiant (Infrared) Heaters:(Standard Unvented Space Heater)
The gas flame is used to heat ceramic panels which, in turn, glow bright red. The heat given off by these panels warms objects in its path in much the same way as the sun warms objects. The room air is not heated directly, but the warmth from the heated objects serves to heat the air gradually.
- Most often used as a back-up source of heat.
- Best for heating people and objects that are fairly stationary in the path of the glowing panels.
- Not as useful for heating whole rooms or sections of a house.
- Can be thermostatically controlled to maintain an even temperature in the area of the glowing panels.
- Can be used with a blower to better circulate heated air around room.
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