Wood burning stoves are an excellent choice if you want to save money on your heating bill and provide the most comfortable heat for your home. There are a number of things to know about wood stoves and how they work before you purchase your stove. There are also many tips that can make owning and operating a wood stove easier, more efficient and a better investment. I have built my own stoves, and heated multiple homes with wood burners for over 40 years.
My advice is derived from this experience and research into the subject for just as many years. From buying (or building) a stove, to supplying wood for burning, to operating an efficient burning system, I have some advice and tips for the novice to the long term wood burner. If you have a question about wood stoves and how they operate, the answer is probably somewhere in this article.
The History of Wood Stoves
Heating with fire has been the norm since after the flood of Noah. People have required warmth and a fire was the simplest method to satisfy this need. From a pit outside a simple home to fireplaces with chimneys, the radiant heat from a simple fire is a warmth that everyone that has been outside in the cold can appreciate.
For centuries wood was the simplest fuel to obtain and use. The mining of coal in the 12th century began a slight change in the fuel used for heat but really was not available in larger quantities to the average home until the 18th century. This is when the industrial revolution created the need for large quantities of coal.
The use of wood as the fuel for home heating was still the leading source into the beginning of the 20th century. The vast quantities of trees that were available, the low cost and being a renewable resource made them the heating source of choice for the masses.
Using an open fireplace was also the primary heat source in most if not all homes until the first wood stoves popped up in the late 1700’s. One of the first inventors was none other than Benjamin Franklin. His invention was the Franklin pot belly stove.
Franklins’ stove was able to reduce the draft that a typical fireplace pulled through a house and radiate that heat from the cast iron surface to the room where the stove was placed. This reduced the cool draft that came through other rooms in the house and made the whole house warmer.
How Wood Stoves Work Today
Now let’s skip ahead to the 1980’s. For those who weren’t around for those days I will recap.
Jimmy Carter was elected in 1976. Due to many factors but primarily his incompetence to be a leader, the US was plunged into an “energy shortage”. There were long lines at gas stations and you were only allowed to fill up on alternating days. Schools were closed or combined because of the lack of fuel to heat them in the winter.
The school I attended was actually turned down to 65 degrees and we were instructed to wear our coats to class. Kids don’t even wear their coats to school today. Inflation was in the double digit territory and everybody’s budgets were squeezed tight. OK, that was where we were at that time. Why is that relevant?
People were looking for alternate sources of heat for their homes. Turning up the heat was frowned upon but to most it was very expensive at the time.
There was an abundance of wood available for fires but few people had fireplaces and they were probably the most inefficient means of heating a home. The design of a steel wood stove started to spread across the country.
Some of us built our own. Others found a reputable company such as Buck Stoves and purchased one. The idea was very simple. Contain the fire in a small steel firebox and blow the heat to other areas of the home or just let it radiate from the stove.
Fires burn based on the fire triangle. Three elements are required to allow a fire to burn. Fuel, air and heat. Remove one of these and the fire goes out. Controlling each of these controls the fire. The new stoves that came out in the 1980’s did just that. The primary means of control was the amount of air that was introduced into the fire.
The Birth of the “Air-Tight” Stove
Just as new ideas are, it was simple. Wood stoves with a sealed firebox made of welded steel walls or cast iron began popping up everywhere. They just needed a door that could seal out the free flow of air and a device that could adjust the air flow into the firebox. A simple fiberglass or ceramic rope was the answer to sealing the stove door.
Many methods were employed to restrict and allow the flow of air into the stoves. From gears that would tighten to the stove on threads to simple metal flaps on a rod, any means of adjusting air was the means of controlling the heat from a stove.
With the capability of controlling the fire came the ability to heat a house comfortably. Fireplaces had always created a draft that left rooms away from the hearth cold. With the limited amount of air a wood stove required, this draft was reduced considerably.
In addition, the amount of wood required was reduced by a factor of 3 to 5 depending on the size of a house. With the air-tight stove, the heat could be controlled by adjusting the air in and turning up or down the heat for a room or house. This made the wood stove a reasonable replacement or accompaniment for the home furnace. If an abundant supply of wood was available, a home could easily be fully heated with a wood stove instead of or in tandem with a furnace.
As it turns out, firewood was very available at this time. Farmers were expanding the sizes of their farmland. Woods were being cleared for farm use and the wood was cheap. I filled many pickup loads of wood for $20 during the years when 20 to 40 acre areas were clear cut to make way for farming.
Saving money and heating a home comfortably were the benefits of owning a wood burning stove in the 1980’s. These are the same reasons most people will install one today. As in all things in life, wood stoves changed. They became more efficient, bigger, smaller, easier to operate and morphed with the times. But the biggest change came when they became regulated.
Yes, the government had to get its fingers into even the most simple piece of equipment in a home. The wood stove. Now we will take a look at how that affected wood stoves and how it came about.
What is PM?
PM stands for Particulate Matter. PM is the chemical reaction of large and small particles in smoke caused by the burning wood. These are then carried out of the chimney in smoke. These particles that are an output of a wood stove are now required to be reduced. Currently, there are three systems using a method that re-burns the PM inside of wood burning stoves.
In stoves that do not re-burn the PM, the particles either escape into the air or collect in the chimney. The PM that collects in the chimney becomes creosote. This can be dangerous and we will look closer at creosote later in the article. PM that escapes out through the chimney into the air can be harmful if breathed, as is any smoke.
Regulations in the 90’s
When a new technology takes off and sales increase, the government takes notice. There were several reasons for the intervention of the EPA into the wood stove manufacturing industry. By reducing the air input to the firebox in the new stoves, the output of the stoves increased the amount of particulate matter that polluted the air.
The output of the stoves had changed due to the reduced air flow into the firebox, and the increased use of firewood as a fuel also caused some users to burn wood that was not seasoned properly. Unseasoned wood (we will look at this later in the article) also causes additional PM or particulate matter to be expelled from the stove.
Starting in 1988, the EPA came out with it’s first regulations for wood burning stove manufacturers.
By 1998 those were re-visited, and the regulations were amplified. They were also further defined as to the method of testing. In 2015 the EPA stated that wood burning stoves would only allow an output of 4.5 Grams per hour of PM. This standard will be reduced again in 2020 to 2.0 Grams per hour of PM.
Starting in the 1980’s there were more people using wood burning stoves, and this caused a firewood shortage per say. This in turn caused people to allow for less drying time for the available wood in the mid-1980s.
Wood as a fuel is one of the renewable sources of fuel we have. More trees can be planted and will replace the trees we burn today.
In the US 1.6 billion trees are intentionally planted each year. This does not include the effect of natural reforestation which is when trees drop a seed that grows without human help.
There are more trees being planted every year than are harvested. Together through planting and natural reforestation, the US exceeds the use of trees by 3.3%. This means through natural re-growth and by planting, every year there are more trees than are used for firewood and the construction industry.
All this history on trees and burning to say that the wood stove industry is like any other industry. The supply of wood (or fuel for the stove) is plentiful for the demand and manufacturers will find a way to meet a demand that is marketable.
As of 2023, there are over 100 wood burning stove models that meet the 2015 standard. The guidelines for PM output regulate that no more than 4.5 grams per hour be expelled from a stove. The guidelines that were set to be enforced for 2020 for PM output are 2.0 grams per hour based on testing with cord wood but are still not finalized.
How Manufacturers Meet the Regulations
Two different versions of wood burning systems have been developed by manufacturers to meet the EPA standards. Catalytic stoves and non-catalytic.
A catalytic stove uses a catalytic device much like a vehicle catalytic converter. This device will re-burn the smoke when heated up to temperature and thus lower the PM that is exhausted out the smokestack.
If you have ever climbed under a vehicle after (or while) it has been running a few minutes, you know the intense heat that is generated by the catalytic converter. That catalytic converter in your car burns up most of the harmful gasses that used to be exhausted into the air. In the same way, a catalytic device in a stove burns up the harmful gasses and particles that would be sent into the air.
One of the drawbacks of a catalytic device is the need to bring the stove up to a very high temperature for it to operate at peak efficiency. To get to this point, the catalytic device needs to be bypassed when it is first lit. This allows the smoke to exit the stove without going through the catalytic device. This helps keep it clean and free from blockages.
So besides burning the stove at a higher heat, the stove does need to be “watched” and the owner needs to understand the proper operation and timing of opening and closing the bypass. In addition, the catalytic device should be removed and cleaned at least once a season. It will need to be replaced after about five seasons. This may be a fairly expensive replacement. Prices are typically $100 – $350 each.
Non-Catalytic Stoves
Non-catalytic stoves are the lion’s share of wood stoves in homes and for sale today. A non-catalytic stove uses a secondary baffle above the firebox to re-burn the smoke. Above this baffle, pre-heated air is introduced to the smoke stimulating the secondary burn. This process has a similar effect as the catalytic device.
The first benefit of a non-catalytic stove is the lower price. They are typically lower but this may just be because there are more stoves built and on the market that are this type. The more likely reason for the higher price is the actual cost of the catalytic device.
The second benefit of the non-catalytic stove is the slightly lower temperature that is required during burning. This provides two positive results including burning less wood since the temperature can be reduced. The additional benefit is when you are heating your home in the spring and fall, the stove temp can be reduced without a negative impact to the wood stove.
The third advantage of a non-catalytic stove is the reduced amount of maintenance. The secondary plate does require cleaning, but this is the same as the rest of the stove.
The Third Type
There is another type of stove that is available and is a combination of both stoves. They are called a hybrid stove. This stove combines a catalytic device and the non-catalytic system into one stove. These stoves are the most efficient when it comes to eliminating the PM and burning up the particles that would be exhausted into the air.
The down side of a hybrid stove is the cost. They are the most expensive wood stove on the market. You will still need to monitor the stove to open/close the bypass system when the stove reaches the correct temperature. In addition the catalytic device will require annual cleaning and replacement when it is no longer collecting the PM as required
Current Stoves
Typical wood stoves have not changed dramatically in the past 50 years if you just look at them from the outside and based on their function. The goal is a less expensive option to heat a home and heat it efficiently. Looking at a stove they are typically black steel or cast material that radiate heat into a room. Hundreds of models are available today that look and do just that.
There are also some stove manufacturers that have made the “Look” of their stove stand out from the rest. Vermont Casting stoves come to mind with their red paint option and stylish glass doors. These can be a centerpiece in a family room area.
The real differences are under the skin of most stoves. The catalytic or non-cat stoves. The pellet or corn burning stoves. Stoves that operate as a furnace and can heat up to 2500 sq/ft homes without filling for days. Outdoor boilers have been installed all over the midwest and across the northern tier of the US.
What is the current state and future for these wood stoves? As the regulations may tighten, most manufacturers of wood stoves have invested R&D in this and do have models that will meet the tighter standards. The stoves that are already installed are not affected by these standards. So far only the manufacturers are required to meet the standards.
The issue here is the testing can only be accomplished in a lab environment. Testing in the field is not possible at this point as the PM disperses into the environment and measurements are not possible.
New Stove Versions
Pellet Stoves
Pellet stoves have made a mark in the past 10 years. As the generation of those who started burning in the 1980’s grows older; cutting, splitting, hauling, stacking, stoking wood and cleaning out ashes is taking on a new look. It is getting old just like us.
A pellet stove still needs to be filled but a 50 lb bag of pellets one time a day is much simpler that 3 loads of wood. That wood also had to be cut, split…you get the idea. That was almost fun in my 20’s or 30’s, work in my 40’s and 50’s. Now it is an accomplishment to complete.
The simplicity of the pellet stove is you pour in the pellets, set the thermostat and watch it heat. The pellets are available at a variety of outlets and do not leave the mess that a wood pile does. I have not converted yet but the uncomplicatedness of one is hard to ignore and many have made the switch.
The ease of venting the exhaust is another plus for the pellet stove. A simple 4 inch dual surface vent pipe is all that is required. Just plug it in and the stove controls the lighting and the air flow.
Outdoor Boilers
The other type of wood heater to make a huge mark on the industry is the outdoor wood boiler. The biggest draw of the outdoor wood boiler is the “outdoor” part. The fuel for the heat never has to enter the home and can be cut and stored near the location it will be burnt.
The next positive aspect of the outdoor stove is the consistency of the heat it produces. The heat is transmitted into the house in the form of hot water. This water is then generally used to heat a coil that is inserted into an existing furnace which is used as an air handler to move that heat throughout the house.
By this means, a house receives the same heat that the furnace provided when it was using natural gas or propane to heat the interior. The only difference is the hot water is the heat source within the furnace.
The water is heated within the outdoor wood stove as with a typical boiler. The firebox in the stove is surrounded by a water chamber. This chamber heats the water to between 160 and 180 degrees F. The water is then pumped from the stove to the furnace in insulated pipes. The water returns to the wood stove to complete the flow of the enclosed system.
The additional benefit is that domestic hot water can also be heated by this system to provide hot water for your hot water heater.
There are drawbacks to these types of systems. First the cost is 3 to 10 times the cost of a typical wood stove. The second is the amount of wood required to make this system operate. Since there is a transfer of heat (several times), this system loses some efficiency in that transfer. Because of that inefficiency, outdoor wood boilers require 2 to 4 times the amount of wood as opposed to a typical indoor wood stove. If you do not have a large supply of inexpensive firewood available, and plenty of free time to cut it, then this may not be the system for you.
Choosing a Wood Stove
The next subject to delve into will be the purchase of a wood stove. Seems simple but a few wise words from someone that has made a few mistakes will hopefully help out.
The first step is to choose a stove for your home. What I mean by that is stoves come in a huge variety of types, sizes and styles. I am not going to get into all the versions of stoves available today but step one would be to find a stove that fits well into the type of home you have. The look needs to match the home. A quick google search of wood stove manufacturers will help narrow this down quickly.
Once you have decided on the style and narrowed it down to a few manufacturers, pick an appropriate size. The saying “Why do when you can overdo” will be painful in a wood stove. You will quickly find that a stove that is too large will overheat an area. Attempting to run the stove at a lower temperature than designed for will cause undesired heating output and extra maintenance and/or damage to the stove and its components.
The same can go for a stove that is too small. Either it will not heat the area or you will have to run it too hot and again maintenance issues or damage to the stove could occur.
Stoves are rated to heat a specific area usually in square feet. Know the size of the area you plan to heat and purchase the stove to fit that area. It’s not rocket science, just simple math. Trust the numbers and you will find the correct stove to fit the space you intend to heat.
Installing a Wood Stove
So you want to install your new wood stove yourself. You may find this way out of your ability and decide to have a professional do the complete installation of the stove. If so, you can skip this portion. If you are a full on do-it-yourselfer, then read on as I attempt to cover the basics of a wood stove installation.
Read NFPA 211
If you plan on installing your own wood burning stove system, step 1 should be to read and follow the NFPA211 standards. This is the standard published by the National Fire Prevention Association on chimneys, fireplaces, vents, and solid fuel burning appliances.
A Standard published by NFPA is just that, a standard. A standard is not a law but instead a set of guidelines on fire safety since 1896.
The standards are generally adopted by other organizations, such as OSHA or state and local governments. These guidelines are to be followed as safety regulations or to receive a permit for building or completion.
The NFPA211 standard uses years of data from past experiences and testing. Following this standard ensures the safe construction and installation of a fireplace or solid fuel device (wood burning stove).
Indoor Stove Placement
Placing the stove in the home is critical to how it heats. A few simple guidelines are; heat rises so place the stove in the lowest reasonable location you can. Stoves are heavy. Place the stove where there are strong structural members to support it. Protect surface areas that burn. Following the guidelines in NFPA 211 will help with this. Last, know where your chimney can be installed. Stoves NEED a chimney. It has to go out, to above the roof line. More on this in the next section.
As far as location, sometimes the choice is made for us, like if there is an existing chimney. Other times we have multiple choices. The key is to choose a location that heats well. A blower on the stove will move the heated air away from the stove, but not down. Hot air only moves up.
In my home, I was able to locate the wood burning stove on a wall adjacent to my propane furnace. This allowed me to connect to my heating duct system in the house to blow warm air from the wood stove through the house.
Another option is to place the wood burner near a cool air return vent. Heat from the stove can be directed into the cool air return duct and distributed throughout the home using the existing duct and the furnace fan.
Find a location as near to an entrance as possible. There will be many trips to the outside for wood, the closer to the door the better. Again, at my house, I was able to install a small door in my utility room wall as a pass-through for wood. I have a wood box that sits on the outside of the house on the other side of the door.
Protecting the Floor
The floor under the stove must have a fire/heat resistant surface installed. Brick or a surface that is modular should be used. Many variations are available in different sizes, shapes, and colors.
Make sure the floor in front of the stove is covered several feet out from the door. Hot coals and shooting sparks will fall out in front of the stove when adding wood and when cleaning.
Protecting the Walls
The wall behind or beside if the stove is in a corner should have a protective surface on it. Brick, stone, or a heat resistant material should be installed behind the stove to protect the walls from excessive radiated temperatures.
The required distance from a wall behind and beside the stove is detailed in NFPA211. The stove manufacturer should also provide guidance in the installation manual.
Getting the Stove In
It may sound silly but measure the stove from every angle and then measure your doorway. Yes, I actually built a stove that did not fit through my doorway. I had to take the stove back to the shop and cut the ashtray off the front and make it so it was attachable after it was in the house. Larger stoves may be a problem for some doorways.
Installing a Chimney
The chimney is the most important portion of the wood burning system. A properly installed, safe chimney is important because it is where most wood stove fires occur.
Picking the location of the chimney will limit the type of chimney to use. In an existing home, a masonry chimney could generally only be added on an outside wall.
A masonry chimney is made of a flue inner-liner constructed of clay or glazed tile. Then a layer of block surrounds the flue for stability. The exterior is made of brick or stone for a finished look and seals the chimney from the elements. Topping off the masonry chimney is a crown that seals the top from the weather.
A wood burner can be connected to an existing masonry chimney if the size of the flue meets the requirements of the stove. A chimney insert may be an option, but in either case, the chimney should be inspected by a chimney professional.
A double-wall or triple-wall chimney system is an option if the chimney is installed straight up and through the roof. Both systems require a ceiling support box when installing the system through the ceiling. A single wall pipe connects the stove to the ceiling. From the ceiling to the roof requires double or triple wall pipe.
Roof flashing has to be used to shed water off the roof. Then the chimney pipe should extend at least three feet above the peak of the roof. A cap needs to be installed on the top to keep birds out of the warm chimney and sparks from leaving the chimney when burning.
There are dozens of accessories for double and triple wall chimneys including T’s, clean-outs, collars, wall straps, and roof supports. Purchase these parts and pieces as required. Just plan ahead and have what is needed when installing.
The route of the chimney should be thoughtfully planned out. The proper clearance to any combustible surface should be closely followed.
Safety for Wood Stove Owners
Looking at statistics, the most common cause of fires in homes (according to an NFPA report 2012-2016) was home cooking accidents. The second leading cause at 15% of home fires was home heating appliances. This includes gas and propane furnaces, space heaters, and solid fuel burning appliances (which are wood burning stoves).
Wood burning stoves are only a portion of this statistic, and again the fire is generally found to start in the chimney. Why is this and is there anything that can be done about it?
What makes the chimney the danger zone of a wood burning system?
What we soon found out was that reducing the air flow into the stove had a negative effect on the smoke that left the stove. By reducing the air input to the stove, the smoke that now drifted slowly up in the stove and out the chimney would carry additional Particulate Matter (which we know as PM). At the lower temperatures, the smoke left a residue on the walls of the stove and especially on the chimney wall called creosote.
The tar-like substance would eventually collect and build up to a point where it would clog the chimney. It could reduce the inside diameter of the chimney to a point where the smoke would back up in the wood burning stove and enter the home.
Cleaning a Chimney
At this point the chimney requires cleaning. A do it yourself homeowner can clean the chimney if they can safely get to the top of the stove pipe. You must also have the correct tools such as a ladder, chimney brush (that fits the exact size of your chimney pipe) and fiberglass rods that reach the entire chimney length.
If you are not 100% sure of how to clean and inspect a chimney, my recommendation would be to hire a reputable chimney cleaning company to complete this job for you. As mentioned earlier, the chimney is the primary location for fires in homes with wood burning stoves. Maintaining the chimney correctly is crucial to the safety of the wood burning system and the safety of your home in general.
Best Wood to Burn
Choosing the correct wood to burn and seasoning it properly is one of the simplest ways to keep your wood stove and chimney clean. I had to learn this the hard way back in the 1980’s as there were no forums, chat rooms, or google to query about this (or anything else).
Hardwood
It is always best to burn hardwood when available. Hardwood is denser and heavier in weight and has more volume of matter to burn. When you pick up almost any piece of hardwood, it is obvious by the weight with a few exceptions of softwood that hold large amounts of moisture in the wood.
Once the wood is dry or seasoned, hardwood will stand out as a denser, heavier wood always in comparison to dry softwood. Hardwood also cuts (with a chainsaw) harder and slower than softwood. These qualities also make it a better burning wood. Here are some examples of the best burning hardwoods with their typical weight and BTU rating per cord.
Applewood is an excellent hardwood that not only burns well but has a great smell to the smoke. Applewood is used to make pellets for smokers and chips for standard grills because of this quality. Apple trees are not very large, so the wood generally does not require splitting to burn. It takes several (maybe 10) apple trees to make a cord of apple wood.
White ash was one of my favorite woods to burn until the emerald ash borer wiped out most of the plentiful ash trees in northern Ohio and across the mid-western U.S. over the past 15 years. The large supply of the plentiful and excellent burning white ash trees have almost disappeared from the area. The ash wood would split easily, burn hot, and leave a small number of ashes when burnt.
Cherry wood is similar to apple wood in burn quality and has a nice aroma to the smoke. It is also a small tree and takes up to 10 trees to make a single cord of firewood.
Dogwood is a good choice when available, requiring little splitting because of its small limb size. Dogwood is not plentiful in the midwest, so it is rare to get as firewood.
Black Locust wood is also a great wood to heat with, but it is difficult to split due to its stringy grain. This means the split pieces do not “pop” apart like ash wood. Instead, the wood must be split along the entire piece of wood as it “sticks” together. It does burn well and has a long constant heat.
Maple wood is a marginal hardwood. It is very common and available in the northern US. It splits well and burns well but leaves more ashes than most hardwoods.
Red and White Oak (White oak is readily available in most of the U.S., red oak mostly in the south) are both excellent burning wood. White oak splits second only to white ash, generally very easy with a “pop” when it is struck. White oak is very available to the wood burning general public and leaves the least amount of ash of any wood that I burn.
The wood from Osage orange trees is available but not in large quantities. It has one of the highest BTY ratings of wood available in the northern US of 32.9 million BTU’s per cord of wood.
Black walnut is also an excellent burning hardwood. There are plenty of black walnut trees available and are generally removed from yards because of their annoying large green nuts that are of no value. The dark wood is, on the other hand, desired by woodworkers for crafts and projects.
Hickory is a nut tree that is one of my favorite burning woods. It is not as plentiful as in the late 1900s. It is a medium, easy splitting wood that “pops” when hit correctly but can have knotty areas. It is second in BTU’s only to Osage orange and is slightly hotter burning than white oak.
Hardwood Types
| Species | Green Weight Per cord | Dry Weight Per Cord | Millions BTU’s Per Cord | Ease of Splitting |
| Apple | 4850 | 3890 | 27.0 | Medium |
| Ash, Green | 4180 | 2880 | 20.0 | Easy |
| Ash, White | 3950 | 3470 | 24.2 | Easy |
| Beech | 3760 | 27.5 | Easy | |
| Cherry | 3690 | 2930 | 20.4 | Easy |
| Dogwood | 4230 | 27.0 | Difficult | |
| Hackberry | 3980 | 3048 | 21.2 | Easy |
| Black Locust | 4620 | 4020 | 27.9 | Difficult |
| Maple | 4680 | 3680 | 25.5 | Easy |
| Sugar Maple | 3900 | 2750 | 19.0 | Medium |
| Mullberry | 4710 | 3712 | 25.8 | Easy |
| Red Oak | 4890 | 3528 | 24.6 | Medium |
| White Oak | 5570 | 4200 | 29.1 | Medium |
| Osage Orange | 5120 | 4728 | 32.9 | Easy |
| Black Walnut | 4584 | 3190 | 22.2 | Easy |
| Hickory | 5400 | 4650 | 29.2 | Medium |
Medium Hardwood
The next group of wood species identified is medium wood. This group, in general, has a very high moisture content when cutting but very low moisture content when it is dry or cured. I would typically only burn this group of wood in the early fall or late spring when I do not need as much heat. I would also verify that the wood is dry and seasoned to the 15% to 20% moisture content level.
Plentiful in new growth woods in the midwest is Basswood. Easy to split but heavy on ashes, it is not a great burning wood but will do when you only require 10 to 15 degrees F of heat rise in the spring.
Birch is actually one of the better burning woods in this category at 20.8 million BTU’s/cord. It will dry out fast and eventually burn like paper so don’t let it set too long (3 – 4 years).
Horse chestnut or Buckeye trees in Ohio are also in this category. This wood loses more than half its weight when seasoned. Not the best burning wood but again, okay for early fall.
Cottonwood is very plentiful across the U.S. This tree is considered a nuisance because it constantly drops limbs and the flying “cotton” from the tree in the spring is awful on allergies. It burns better than most in this category when cured, and it splits easy. Cottonwoods are quickly replaced when cut because they grow 20-30 feet in several years.
American Elm is the best burning wood in this group as it comes in at 20.0 million BTU’s/cord. It is a stringy, difficult wood to split. It does add a good fragrance to the smoke.
Silver maple is added to this category with a 19.0 million BTU’s/cord rating. It splits medium and has a good fragrance. I had not mentioned it earlier, but as in the hardwood category, silver maple creates good hot coals after it burns. This promotes a good base to add wood to so the fire continues to burn hot.
Sycamore and willow finish off this category of medium woods. Sycamore is a difficult wood to split and willow an easy splitting wood. Both burn about the same in the upper end of this group of wood types.
Medium Wood Types
| Species | Green Wt. Per Cord | Dry Wt. Per Cord | Millions BTU’s Per Cord | Ease of Splitting |
| Basswood | 4400 | 1980 | 13.8 | Easy |
| Birch | 4310 | 2990 | 20.8 | Medium |
| Horse Chestnut | 4210 | 1980 | 13.8 | Medium |
| Cottonwood | 4640 | 2270 | 15.8 | Easy |
| American Elm | 4460 | 2870 | 20.0 | Difficult |
| Silver Maple | 3900 | 2750 | 19.0 | Medium |
| Sycamore | 5090 | 2800 | 19.5 | Difficult |
| Willow | 4320 | 2540 | 17.6 | Easy |
Softwood
The final category of wood species is softwoods. Burning these is typically a last resort for me. I generally do not waste time or energy on soft wood as the heat that it produces is so minimal it is not worth the effort.
If some are thrown in with a load that was delivered to me, I usually move it to my campfire wood to burn outside. If softwoods are all you have available, then here are some of the types and details of these woods. All of these softwoods split easily.
White fir does make a good kindling wood. This would be used to start a fire quickly. When split into 1″ x 6″ pieces, this will quickly ignite and hardwood can be placed on it to start the real hot fire.
Softwood Types
| Species | Green Wt. Per Cord | Dry Wt. Per Cord | Millions BTU’s Per Cord | Ease of Splitting |
| White Fir | 3580 | 2100 | 14.6 | Easy |
| White Pine | 2900 | 2250 | 15.9 | Easy |
| Spruce | 2800 | 2240 | 15.5 | Easy |
Seasoning Firewood
The step skipped by many people who wait until the last minute to get firewood or do not have room to store it is seasoning. It is one of the most critical steps in burning wood. Properly seasoned wood will burn hotter, cleaner and safer. Let’s look at why this is.
Wood for burning should be dried or seasoned to 15% to 20% moisture content. As you can see by some of the charts, this can reduce the weight of the wood by 1/3 (most hardwoods) to as much as 50% in some softwoods. Allowing the wood to dry and lose its moisture is necessary for the wood to burn properly. Wood that is too “wet” will waste heat as the heat created is used in drying out the wood.
Wood should be cut and split at least six months and preferably 12 months ahead, so it has sufficient time to dry. It should then be stacked in single rows, off the ground to let air move through the wood to dry it thoroughly.
Wood that has been dried to the proper moisture content will provide the maximum BTU’s per cord and will leave the least amount of ashes to be removed from the wood burner.
Properly seasoned wood will also burn “safer” as it will produce less PM or Particulate Matter. These are the contaminants that exit the chimney and stick to the walls of the chimney causing creosote buildup.
Properly seasoning your firewood is an efficiency issue as well as a safety issue. Plan ahead to have your wood supply delivered, cut, and split well in advance of the burning season.
Storing Firewood
It may again seem like a simple thing but storing firewood correctly will make the wood burning process much easier in the long run. Just leaving the wood laying in a pile on the dirt can cause a multitude of issues.
First, keep it up off the ground. Old pallets are a cheap solution or at least a row of old wood that you sacrifice to protect the new wood. The wood draws moisture and bugs from the ground and adding moisture to the wood is not desirable.
Then, your wood should be placed in storage to dry to the proper moisture content and stay dry. You do not necessarily have to move the wood, but It should at least be covered. A simple tarp will do. Just covering the wood with a watertight cover will maintain a consistent moisture content where it is for several years.
A wood shed is an option to dry and then store wood in without moving the wood. A wood shed has a roof to protect the wood from rain and snow but has open (6″ gaps) in the walls to allow air to move through the structure and through the wood.
Storing wood inside an enclosed barn or shed is fine also. I would not recommend this long term. The gaps in wood storage allow mice and other critters to nest in the piles. Having a cat or mouse traps to reduce the population is highly recommended, or the pests will take over. The wood will remain dry for long periods of time but rotating the supply will keep it fresh and disrupt the mouse population.
Where to get Wood
If you have a wood stove already, you may have a source of continuous firewood. If you don’t, here are some ideas on where to find affordable firewood.
The Definition of a Cord
A cord of wood by definition is 4′ x 4′ x 8′. That equals (doing the math) 128 cubic feet of wood. No split, stacked pile of wood will be exactly the same. Split wood is not square and stacks very unevenly; this leaves gaps and air space; less wood is in the pile or cord.
Wood burners do not hold a 4′ long piece of wood other than some outdoor boilers. Generally, the wood is cut into 16″ long pieces; however, nobody cutting wood with a chainsaw is using a tape measure on every cut! The length is approximately 16″.
If you are buying wood, take a tape measure with you (if the seller is offended, too bad)! You are paying; you should check the length, height, and width. Do the math. Make sure you are getting and paying for 128 cubic feet of wood (approximately) per cord of wood.
Suppliers of Cut and Split Wood
The best source of cut and split wood in most communities is tree trimming companies. They will have supplies of hardwood that has been seasoned and is available for inspection.
Most will have wood on racks (that can be measured) ready to be loaded in your truck or trailer.
If you don’t have a truck or trailer or just don’t want to load and unload the wood, ask if they will deliver the wood to your address. Depending on the distance, many companies will deliver a load of wood for free.
The more wood you order, the more likely the supplier will be willing to make a deal, such as three cords of wood for the price of 2 or 2 1/2. That would be a great deal! Just make sure the delivered cords are full cords!
The same goes if you are loading and hauling it yourself. Making a larger purchase may give you a break in the price. It depends on the supplier and the time of year. Supply and demand still determine the market price.
You should also be familiar with the types of wood that are available in your area. You do not want to pay top dollar for softwoods like pine or cottonwood. Softwood is plentiful, and tree trimmers have supplies of it, but it does not burn well
Burning hardwood is preferable because it burns at higher BTU’s (British Thermal Units) than softwood, burns longer, and has less ash to remove. See the section above for advice on wood types.
Learning about different types of wood is not hard; it just takes experience. The grain of the wood, the bark and the smell all tell what type of tree it was. The first and most important test for hardwood is the weight of the piece of wood. Pick up a piece of white oak and the same size piece of white pine. The difference is obvious immediately. The oak weighs three times the pine.
Uncut Wood
I have found uncut wood in many different places in the past. I do this less as my muscles tend to resent the additional work as I age. There is also much less of it available. The companies that sell wood get the better price for cut, split wood in smaller quantities.
Farmer’s Tree Line
Farmers need tree lines cleared. There are many large farmers that farm hundreds to thousands of acres of land. The tree-lines along or between fields need cutting or thinning. Forming relationships with these farmers can pay off.
If you cut and remove the unwanted trees for free, that will save them time and work. Most farmers will be thrilled at the chance to save one or both! You can usually only get into the field in the late fall or winter. That is the best time to cut trees anyway.
Lumber Mills
Some areas of the country have large mills, and other areas of the country have small family run mills. The large mills usually have a source to dispose of or sell the slab wood that is removed from large lumber. Many times the slabs are used to make pellets or other manufactured wood products.
Small lumber mills, on the other hand, make this slab wood available for purchase to the public. They will bundle the slab wood and sell it for firewood. It does have to be cut and will also include a large amount of bark. Tree bark is not the best part of the wood to burn and also leaves a lot of ash to be removed from the stove. It is generally an inexpensive wood source. It is also less work than logs as it does not require splitting; only cutting to size to fit your stove.
Small lumber mills may also be a good contact for cutting in woods. If they own or rent forest land, they may want trees cleared out for better growth. The owner will specify what trees to cut or more likely will only allow downed trees to be cut for firewood.
Clearing out the downed trees will encourage the woods to grow faster and more efficiently for the desired lumber. A cleaned out woods leaves room for new growth, planting, and more space for large hardwood trees to expand.
Pallet Factories
With the recent boom in industry and consumer spending, pallets are in high demand. Pallets are not always re-used, and new pallets are constructed daily by the 1000’s.
A pallet factory near me cuts all its own boards from 6″ x 6″ x 10″ lengths of wood. After the pallet boards are cut the end pieces are left over. These end pieces are waste for the pallet factory. Many of them will sell these pieces of leftover wood for firewood.
The leftover pieces range from 2″ x 2″ x 2″ to 6″ x 6″ x 24″. The smaller pieces make great fire starters or campfire base wood. Most of the wood is oak, which is excellent wood burner firewood and none of it has bark. This means less ash and fewer clean-outs of the wood stove.
The wood for pallets has been dried or cured to some degree. This wood is usually ready to burn from the pallet factory, but a simple test with a moisture meter will provide accurate readings.
This wood will also stack nicely as it is flat cut with no bark. If the wood does require time to dry, do not stack it tightly until it is dry. Tightly packed wood does not get enough air to dry. Leave it in a rough pile until the sun and wind do their job and dry it out.
Cutting Wood
If you cut your own wood, there are some tools you will need to efficiently and safely cut logs into firewood, starting with a good chainsaw. The saw needs to be large enough to cut the size logs you use but not too big to handle for hours at a time. I have found a 20″ – 24″ saw with the horsepower to cut a 16″ log in 20 seconds is an excellent size. I recommend Jonsered, Stihl and Husquvarna. Get the commercial models if you plan on using them regularly. All good brands with years of production behind them.
When cutting in a woods or field always have one or two spare chains. A round file that is designed for the chain you use is handy when you plan a full day of cutting. Touching up the chain with the file saves swapping out a chain. It does take practice to file the proper angle on a cutting tooth.
Safety should always be observed when cutting with a chainsaw. Safety glasses and ear protection should be worn at all times when cutting. Cut in a downward direction with the saw pulling toward the log. When tired, take a break.
How to Heat a Home Efficiently
Heating your home with a wood stove is a great way to save money but getting the most out of that stove takes some thought and effort. There are a number of things you can do to make a stove more efficient and safe. Each one builds on the other. I have already mentioned some of the things you can do such as:
- Choose the best hardwoods to burn
- Season your wood properly
- Store the wood off the ground and under a cover
- Keep the chimney clean and inspected
In addition the following items will help your system burn better and safer.
Removing ashes on a regular basis allows heat from the fire to reach its intended source. Ashes piled on the floor and walls will tend to absorb the heat and deflect it from the air or water chamber it should be heating.
Cleaning the ashes usually takes 30 – 60 minutes and can increase efficiency by 3% – 5%.
Burning hardwood that produces less ash is an efficient way to clean the stove less and allow the wood stove to heat at its maximum proficiency.
Replace the Door Gasket Regularly
The door gasket on a stove can easily be overlooked. They can be easily replaced and avoid allowing too much air into the stove.
The gasket is an integral part of the system that seals the stove and restricts the amount of air that the fire receives. Accurately and consistently controlling the airflow is what makes the stove work so well.
Over time, the creosote will run down the door and make the soft gasket hard. Due to the hardened gasket, the door will not seal as well and will allow additional air to enter the stove, reducing efficiency.
Gasket kits are available that come in a variety of shapes (flat, round), and sizes, and are infused with graphite to keep the gasket lubricated. These kits may also come with the glue required to attach the gasket to the stove or door face.
Replacing the gasket is an inexpensive and simple solution to what could be a major problem for some stoves. Changing the gasket once a season should typically resolve any air leak issues around a wood stove door.
Alternatives
There are several alternative methods that can be instituted to make a wood stove system more efficient. Some are alterations that require planning and installation, and some are simple items that can be purchased and installed in minutes.
Thermal Mass
A thermal mass sounds large because it generally is. A wood stove is usually not a small item, but a thermal mass can take up a large portion of the room around the stove or be part of the floor, walls, basement, or crawl space.
A thermal wall is typically a stove or brick wall, and a floor system that once warmed up will hold the heat for a period of time. This mass can just hold the heat in the area or may have ducts or water pipes running through it to move the heat to the other areas of the home.
The advantage of a thermal mass is it will hold the heat for a long period of time. The disadvantage is how long it takes to bring the mass up to temperature.
Having a system that efficiently stores and distributes heat from a wood burning system requires a well-engineered system. The radiated output of the stove and the heat collection and storage properties of the mass media must be calculated. With a project and installation this large, guessing is not acceptable.
Done properly, a heat mass system can provide long term, consistent heat for an entire home.
Outside Air
Air is one of the three requirements for a fire to burn. The air that feeds the fire is typically drawn from inside the room where the stove is located. If the air for the fire is fed from a single tube, the air can be drawn from outside the home. This reduces the warm air that is pulled out of the home and up the chimney.
A stove that can accomplish this is a much more efficient system. The natural gas systems that are 90%+ efficient draw the air they use to burn their fuel from the outside. Every percentage point that can be gained in efficiency is a little less wood that is cut, split, hauled, stacked, and burnt. My back is feeling better already.
Monitoring the Temperature of the Stove
Probably the least known but best way to make a wood stove more efficient is by knowing what your stove is doing at all times.
Monitoring the temperature of the stove while burning wood is critical to an efficient system. My stove, like 99% of the wood stoves in the world, has had a small, round magnetic thermometer stuck to the face of it for the past 40 years. This thermometer (I have probably only had 2 or 3 of them) has served its purpose and provided the temperature of the stove whenever I was near the stove.
What about the times when you lit the stove, left the door or vents open to get the stove hot quickly, and left the room? You returned to a blazing fire, smoke rolling out of the chimney and maybe even a chimney fire!
There is a temperature sensor available today that will send you an alarm, anywhere, anytime when the stove reaches a pre-set temperature. Not only will it send an alarm, but you can also view the temperature anytime on the free App on your smartphone.
In addition, it is accurate to .1 of a degree so you can know instantly if your stove temperature is rising or dropping. This is critical if you experience a blazing fire as described above. After shutting the doors or vents, knowing if the temperature is still rising or falling can mean the difference between a chimney fire and a quick burn of the inside of the stove.
When it comes to typical burning efficiency, this device will also help you know when the stove cools off too much. A low alarm can also be set, so you are notified when the temperature drops below a pre-set value. This provides you with a consistent temperature rather than the high and low of letting the fire burn out and restarting the stove from cold.
To see the only product of its kind, go to Tempsure.net to view