Living in the country has many wonderful benefits. Peace and quiet. Fresh air! Abundant wildlife! But these benefits are sometimes gained at the loss of convenience. It is generally farther to the nearest Starbucks or Home Depot. Other city or even small-town resources such as water, sewer, and in this case natural gas may not be available where you live.
Cooking or home heating requires some other fuel. Propane or LP gas (Liquid Propane) is the fuel most often used in rural areas. Wood is an alternative form of fuel for heating and is readily available in most rural areas.
What is more efficient, wood stove heat or a propane furnace? A propane furnace is more efficient. When based strictly on cost, wood stove heat is less per season than propane heat. So we will take a look at each form of heat and the efficiency vs. cost of wood and propane.
The Efficiency of Wood Burning Stoves
Wood burning stoves have changed over the past 30 years. They have become more efficient. The popularity of wood stoves increased in the late 1970s and 80s as the “energy crisis” was chocking us out of gas and oil.
Prices for heat were skyrocketing, and reasonable alternative fuel sources were nowhere in sight. Wood stoves were a welcome solution. The early versions would burn one-third less wood and produce four times the heat of a fireplace. There was still quite a bit of heat going up the chimney, but it was better than the high heating costs of the day.
The EPA became involved in the mid-1980s, and the first regulations were imposed by 1988. These regulations required manufacturers to reduce the amount of particles emitted with the smoke from a wood burning stove.
This was a blow to a booming industry. Anyone with a welder and a steel sheer could cut and fabricate wood burning stoves before 1988. The regulations would force the smaller manufacturers out and make the larger companies spend time and money on research and design.
Two main designs emerged and were named catalytic and non-catalytic. Each had its own pros and cons. The end result was a new group of wood stoves that had lower emissions and would operate more efficiently.
The original wood stoves would operate between 45% – 60% efficiency. This means 40% – 55% of the heat was still going up the chimney. Much better than a fireplace that had 80% – 90% of the heat exiting up a chimney.
The newest wood burning stoves (not pellet stoves – covered in a different article) that meet the 2015 EPA standards are up to 70% efficient. This is accomplished by the stove re-burning the smoke in a catalytic or non-catalytic system so that less heat is sent up the chimney and wasted.
Propane Efficiency
Propane furnaces are similar to natural gas furnaces; the newest models are capable of up to 98% efficiency. This means for the fuel that is burnt, in this case, propane, 98% of the heat produced is sent into the home. Only 2% goes up the chimney. That is why new furnace chimneys are actually only an exhaust system composed of plastic, PVC pipe.
Any system that has a rating of over 95% efficient is using the fuel to its maximum value. These furnaces squeeze every last drop of energy (or BTU in this case) out of the propane.
What is a BTU?
BTU or British thermal unit is the unit of measure used in measuring heat output. Technically, one BTU equals the amount of heat to raise one pound of water one degree F. Furnaces are rated in BTU output per hour. This would be how many BTUs per hour the furnace output is in reference to raising the air temperature (in a forced air system) of a home.
When it comes to a wood burning system, the stoves are rated in a similar fashion. Wood stoves are rated in BTU/hour output. The fuel for each is a different story. We will define each of these later.
Efficiency Comparison
It seems like a simple matter, typical propane furnace 95% efficient, typical wood burning stove 70% efficient. Propane wins! But, there are more factors to consider.
A furnace is usually hidden in a basement, utility room, or crawl space. The heat produced is all, or almost all sent out to the home through the air duct system. Some of this heat may be lost if the duct system is in a crawl space or attic. Uninsulated duct pipe will have some heat loss.
A wood stove will typically be placed in a room that is a living space. The heat that radiates from the actual stove and chimney pipe will heat the room and areas around the stove.
Also, the efficient use of a thermal mass can be heated. This area will store heat for hours or even days if it is properly designed.
On pure efficiency, a propane furnace has an advantage, but through planning and design, a wood burner can regain some of the heat that would be lost up the chimney.
BTU Output of Wood
Different types of wood produce different BTU’s of energy. Generally, the harder the wood, the denser it is, the more BTU’s it will produce. This table has a good selection of firewood BTU values.
Choosing White Oak, we have 30,600,000 BTU’s per cord of wood. If we burn three cords in a season, we will have used 91.8 million BTU’s to heat the home. Since the stove is (assuming a good stove) only 70% efficient, it will produce 64.3 million BTU’s over the season. The remainder of the BTU’s or heat is lost up the chimney
| Wood Type | BTU’s |
| Rock Elm | 32,000 |
| Shagbark Hickory | 30,600 |
| White Oak | 30,600 |
| Bitternut Hickory | 29,200 |
| Sugar Maple | 29,000 |
| Beech | 27,800 |
| Red Oak | 27,300 |
| Yellow Birch | 26,200 |
| Red Elm | 25,400 |
| White Ash | 25,000 |
| White Elm | 24,500 |
| Red Maple | 24,000 |
| Tamarack | 24,000 |
| Black Cherry | 23,500 |
| White Birch | 23,400 |
| Black Ash | 22,600 |
| Green Ash | 22,100 |
| Silver Maple | 21,700 |
| Manitoba Maple | 19,300 |
| Hemlock | 17,900 |
| Balsam Poplar | 17,260 |
| White Pine | 17,100 |
| Basswood | 17,000 |
| White Cedar | 16,300 |
| White Spruce | 16,200 |
| Balsam Fir | 15,500 |
BTU Output of Propane
Propane is delivered and measured in gallons. One gallon of propane provides 91,547 BTUs of heat. We will assume an average home of 2,200 sq. ft. with a 95% efficient furnace, heating to 72 degrees for 6 months in the mid-west U.S. We will use approximately 980 gallons per season. That totals 89.7 million BTUs consumed to heat the home. At 95% efficiency, the furnace will produce 85.2 million BTUs over the winter.
Efficiency Conclusion
Propane – 89.7 million BTUs consumed – 85.2 million BTU output
Wood Heat – 87.3 million BTUs consumed – 66.1 million BTU output
The house heating with a wood stove will be a little cooler in the rooms that are away from the stove and warmer in the room where the stove is located. This is typical in homes with wood burners. The other option is the wood heated home will use more wood in a season, and be warmer in every room.
Propane is more efficient on a pure fuel and even heat in a home basis. Now let’s switch gears and look strictly at cost for a season of heat.
Propane
Propane is stored as a liquid, so it is commonly referred to as liquid gas or LPG. It is produced from two sources. It is a byproduct of the crude oil refining process. The majority of LPG today comes from natural gas production. With the large amounts of shale oil deposits located in the northeastern U.S., supplies of LPG are sufficient for the foreseeable future.
Propane Cost
Gas prices have slowly risen since 1990, starting at about $1.00 per gallon in 1990. Since then they rose to approximately $2.50 a gallon in 2008. The price had leveled off with only a slight spike in 2014 when all energy prices took a jump.
This is based on a national average in the U.S. and will vary from location to location and from company to company. As in any industry, buying larger quantities (like a co-op) will earn you a lower price per gallon and smaller qualities will do the inverse (lost more per gallon).
The 2008 shale oil finds in the U.S. and Canada seem to secure a reasonable fixed price for LPG over the next 15-20 years. Of course, as supplies are exhausted during an extreme winter, prices will rise as spring draws closer. This is a typical short term supply and demand. If you use larger quantities of propane, setting a budget with a provider in mid-summer is the best way to assure a lower per gallon price for the entire winter season so if we take the average of $2.50 a gallon for propane and multiply that time the average usage in the Midwest, a 2,200 sq. ft. home uses 980 gallons per season, which equals $2,450.00 per season for propane.
Wood Burner
In the U.S., 2.5 million homes use some source of wood heat as the primary heat source. Another 9 million homes use wood as the secondary heat source. The majority of those are wood burning stoves.
Wood burning stoves started mass production in the early 1980s. The market was ripe for an alternate heat source shortly after the energy crisis of the late 1970s. Wood burning stoves were designed to operate more efficiently by reducing the air flow into the firebox of the stove.
Other innovations were introduced including adding a blower to the stove to circulate heat and push it away from the wood-fired heater. Glass doors were included on most models to allow the large black box to add a bit of ambiance to the room.
Heating the home while watching a fire burn was a great marketing tool for wood burning stoves. Unfortunately, the glass would become stained black with creosote, and other contaminants if proper air flow was not provided to the glass. Regular cleaning of the glass was necessary.
With wood burning stoves capable of burning wood for 8 hours or more, the technology was mainstreamed. By 1990, almost 9% of U.S. homes used wood as a heat source for their home in the cool or cold winter months. Wood for burning has been and still is a plentiful and renewable source of heat.
The sales of wood burning stoves dropped in the late 1990s as the price of abundant natural gas dropped, and the regulations on wood burning stoves tightened.
As sales of the wood burners increased in the mid-1980s, regulations were first imposed by the EPA on the manufactures in 1988. This reduced the manufactures of stoves from around 400 companies to 150 by the early 1990s. The added equipment necessary to meet the EPA regulations along with the increase in production by the lack of manufactures would lead to a sharp increase in price. The regulation was steadily increased and will reach the toughest standard by 2020.
The remaining manufacturers are targeting the 2020 standard, and most have models in production that will meet or exceed those standards by the deadline.
Wood Burner Cost
We can spend hours on the list of items that would add up when cutting our own wood. Chainsaw, parts, sharpening, gas, oil, and the list could go on but needless to say, the more you do yourself, the more you save. Also, the more money you spend on items that make the job easier and faster, the more of your own valuable time is saved.
“On the other hand”, as Tevye says in Fiddler on the Roof, how much is your time worth? That is an equation you will have to work out for yourself.
Doing the least amount of work yourself, a cord of hardwood, delivered, will run around $275.00, more or less, depending on where you live and what type of wood you are purchasing. This would total $1,100.00 and removing all the other factors, including cutting, delivery, and splitting. You still have to stack it and load the wood burner.
If you have access to the wood, a truck, chainsaw, and a log splitter, you can cut this cost to $100.00 for gas and oil, plus your time spent. Again, this is your call!
Cost Conclusions
From a purely cost evaluation, assuming the firewood is purchased and delivered. A season of firewood will cost $1,100.00 vs $2,442.00 for propane. That is a $1,342.00 savings per season.
If you have access to firewood at a reduced cost or possibly for free, that increases the savings significantly, it does, however, increase your time spent on cutting, splitting, stacking, and hauling wood to your home. It is an investment in your savings for that year! Not a permanent investment!
There are also ways to save on propane cost. There are co-ops that share in the bulk cost of purchasing that may reduce the final price per gallon as much as 40%. This would reduce the cost per gallon as low as $1.50 per gallon. The result would be a season total of $1,495.00. Still more than a season of wood purchased but significantly lowers than normal retail.
LPG vs. Wood Heat Labor
When I was in my 20’s, and even my 30’s, the work involved in cutting wood for heat was not an issue. I enjoyed cutting wood. (I had a BIG chainsaw). Splitting wood was a family task (I had a log splitter). The goal was to see how quickly the pile could grow!
Now that I’m 60 years old and the kids are grown and gone, and I’m cutting and splitting by myself, the task goes slower, and I hurt more afterward.
There is a defined and steady amount of labor that is required to burn wood for heat. Some of the tasks can be made easier with the right equipment, but that equipment comes with a cost. Here is a list of equipment that can make cutting wood easier.
- Trailer with a dump box – you still have to load it!
- Bobcat – Which I never owned but would have made moving wood eerier
- 24′ or larger chainsaw
- Vertical log splitter
These are a few of the high-end accessories that make wood burning easier. The question is, after I purchase these items, have I really saved money?
Along with cutting, splitting, stacking, hauling wood, there is an additional list of maintenance required to keep a wood burning system operating efficiently and safely.
Cleaning Ashes
Burning wood leaves a pile of ashes behind. Generally, a good hardwood like oak leaves fewer ashes than most softwood. Regardless of what wood you burn, these will be ashes, and you will need to remove them from the stove. For most stoves, it is not a difficult task, but it must be done once a week or every other week.
The stove will need the temperature reduced and in some cases, extinguished when cleaning out the ashes. Following the manufactures, recommendations are advised.
Safety is the primary concern when cleaning out ashes from the stove. Any remaining hot coals can ignite whatever they land on. My recommendation is always to leave ashes to sit overnight in an ash bucket or, if you are not able, dump them on a garden or some other safe area. Placing them in the garbage is just asking for a fire.
Some stoves have an easy clean ashtray that makes quick work of the task and saves on transferring the ashes to another container for hauling.
Just be aware that cleaning ashes will be a regular, required task if you are purchasing a wood burning stove or a home with one.
Chimney Cleaning
Although you will not see the creosote buildup in the chimney the same as you see ashes build up in the firebox, it is happening. The buildup of creosote in a chimney will happen if you are burning wood at a reduced temperature or if you are burning wood that is not seasoned properly.
By reducing the input of air into the wood burning stove, the efficiency of the stove is increased, at the same time, the smoke exiting the stove is depositing creosote and other particles on the cooler chimney surfaces as it drifts upward.
The newer models of wood burning stoves reduce this by re-burning the smoke and eliminating most of the harmful particles that would stick to the chimney. Some particles still deposit on the walls of the stove and in the chimney.
Any wood burning system should have its chimney inspected on a regular basis. A masonry chimney should be inspected by a masonry professional at least one time each season. The homeowner should also check the chimney system every month if possible, especially if there is a connecting pipe between the stove and the masonry.
A double or triple wall chimney system should also be checked monthly during the burning season to verify it is free of creosote and buildups. The system should be cleaned if any buildups of creosote are visible.
Firing the Stove
Another necessary skill when owning a wood burning stove is the ability to light the stove when it is extinguished. Whether you have to leave home for a weekend in the winter or just put the stove out to clean it, re-lighting is required.
Some wood burning stoves are equipped with a built-in (or attached gas) system to quickly and easily re-light the stove.
The rest of us need a method to quickly and efficiently light the stove. My dad would never approve (he required one match and no paper), but I use a small propane torch to light my wood burner quickly.
Always leaving some coals in the bottom as a base for a fire, I add a pile, 4″ – 6″ of kindling to the coals, then, pile the larger “firewood” on the kindling.
After 9 to 10 minutes of flame directed on the coals, the fire is usually flaming. I will shut the doors about 10 – 15 minutes later, and the stove will be back up to temperature in 2 to 3 hours.
I do not recommend using paper or cardboard when starting a fire in a wood burner. The paper could light, break away, and float up the chimney. This burning paper could get caught on a creosote deposit and start a chimney fire. The only thing you want going up the chimney is smoke!
The list of labor required to supply, operate, and maintain a wood burning stove is not short. I am well aware as I have completed all these tasks for almost 40 years. I do enjoy the heat from my wood burning stove, but there is a significant amount of work associated with burning wood for heat.
Turning up the thermostat on the LPG furnace is much easier. On the other hand, the cost of propane is significantly higher. Again, a personal choice!
Wood Burning Stove Options
Two additional options exist for burning wood as a source of heat for you home.
- Outdoor wood stove – Hydronic Heater
- Pellet Burner
Here is a brief look at each.
Outdoor Wood Stove – Hydronic Heater
Outdoor wood stoves have been around for several years. There are pros and cons to this type of wood heating system.
Outdoor Wood Stove – Pros
The stove sets outside, so the wood does not have to be brought into the home. Firewood will bring in some bugs and dirt, making somewhat of a mess.
The wood can be stacked very near the stove, outside. This makes fueling the fire a short haul for the fueler.
The chimney system, the most common source of fire in a wood stove system, is completely outside and generally far from the house. Much safer!
Heating the home with water can be a more consistent heat than moving air. A forced air system will turn on – off – on – off.
Outdoor Wood Stove – Cons
The heat must transfer from the firebox to water, pump the water to the house then transfer from the water to forced air. The water transfer system is an add on to your existing furnace.
There is a loss of efficiency in the multiple transfers. This generally results in a much larger usage of wood. In some cases 2 to 3 times as much wood. You must be prepared to buy or cut a lot more firewood!
You also do not receive the radiated heat from the wood stove. This is a very warm advantage with an indoor stove. The stove is outside, so you have to go “outdoors” every time you load it, three to four times a day!
Pellet Burners
Pellet burners are a more recent introduction to the market. Pellets are produced from the ground up wood-products such as leftover pieces in a lumber mill, used pallets, and other used wood products.
These wood products are dried to a desired moisture content and then formed under pressure into the ¼” pellets and bagged for sales.
This manufactured product allows for a very consistent burn process, the pellets burn almost 100%, so very little ash is produced in pellet burning systems.
The burn process is also started and controlled by an electronic system that can monitor the temperature output of the stove. This produces a comfortable, consistent heat from the pellet burner.
The dry fuel and controlled burn allow for the exhaust to be much lower than other wood burning systems. The system does not require a high heat chimney as in a typical wood burning stove. The typical output from a pellet stove is 120 – 350 degrees F. This allows for a less expensive and simpler to install a chimney system for the pellet burner.
The fuel of pellets is also available at most home stores throughout the wood burning season at consistent prices.
Conclusion
Although more efficient at burning its fuel, propane is nowhere near as efficient as a wood burning stove when it comes to the out of pocket costs. You can save hundreds or even thousands of dollars by burning wood (depending on your wood source) as opposed to filling your LPG tank.
Burning wood is definitely more labor than a propane furnace. If you have the time and the energy to spare, burning wood is a rewarding home heating alternative that can save you money.
For facts regarding burning wood more efficiently, see my articles, 17 Tips for Burning Wood More Efficiently and Wood Burner vs. Pellet Stove.