HEATING YOUR HOME WITH WOOD
More people are heating homes with wood, but most have not evaluated the benefits and costs. Wood heat is not necessarily the cheapest source of heat and it requires more work. It is less convenient than heating with fuels that are fed automatically. Wood is dirty, requires more planning to use, and wood burning systems require more frequent maintenance, however, if the cost of wood is low enough, you will save money. Also, you will enjoy the warm fire and feeling of self-sufficiency. For those who enjoy the work, cutting, splitting, and stacking can be a pleasant form of exercise.
To compare heating costs you must convert costs of different fuels to cost per unit heat. Cord of wood, gallons of oil, kilowatt hours of electricity, therms of natural gas, and cubic feet of L.P. gas must be converted to a common heat content unit for comparison. The heating value of wood, the stove used, and frequently required stove adjustments make wood heating calculation less precise than other fuel sources.
Which Wood Is The Better Buy?
When different woods are available, a value comparison can be made.
| Digger Pine | 20.5 million BTU/cord | $5.37/million BTU $110.00/cord |
| Incense Cedar | 16.0 million BTU/cord | $7.50/million BTU $120.00/cord |
| White Oak | 28.2 million BTU/cord | $4.61/million BTU $130.00/cord |
Compared in this way, it is easy to see that White Oak is the less expensive heat source.
How To Compare Wood With Other Fuels
Compare the value of firewood in the same way you compare woods. Calculate the price you pay for actual heat obtained from conventional fuel by multiplying the following unit numbers by your cost per unit indicated on your bill:
| Units per million BTU Efficent heat |
||
| Natural Gas | 15.4 Therms | |
| LP Gas | 16.5 Gallons | |
| Electricity (Radiant) | 293.1 Kwh | |
| Electricity (Heat jPump) | 147 Kwh | |
| Combustion Efficiency of Typical Heating Units |
||
| Style | Efficiency | |
| Standand Fireplace | up to 10% | |
| Fireplace with metal liners or tube grates | up to 20% | |
| Simple updraft stove (Franklin type) |
up to 30% | |
| Airtight stoves | up to 60% |
Example: Your electricity costs $.08 per Kwh. Is it less expensive to burn white oak at $130.00/cord in your Franklin stove with 25% efficiency?
Electricity gives 1 million BTU's from 293.1 Kwh. Therefore, the cost for 1 million BTU's is $23.45.
White oak contains 28.2 million BTU's per cord. Therefore the cost of 1 million BTU's is $18.44. ($130 divided by 28.2 divided by .25 stove efficiency) Therefore, white oak provides less expensive heat than radiant electricity.