Firewood Facts
Firewood Facts (based on data from Utah State University Forestry Extension)
Species | Weight (lbs./Cord) | Heat per Cord (Million BTUs) | % of Green Ash | Ease of Splitting | Smoke | Sparks | Coals | Fragrance | Overall Quality | |
---|---|---|---|---|---|---|---|---|---|---|
Green | Dry | |||||||||
Apple | 4850 | 3888 | 27.0 | 135 | Medium | Low | Few | Good | Excellent | Excellent |
Ash, Green | 4184 | 2880 | 20.0 | 100 | Easy | Low | Few | Good | Slight | Excellent |
Alder | 2540 | 17.5 | Easy | Moderate | Good | Slight | ||||
Ash, White | 3952 | 3472 | 24.2 | 121 | Medium | Low | Few | Good | Slight | Excellent |
Aspen, Quaking | 2160 | 18.2 | Easy | Few | Good | Slight | ||||
Basswood (Linden) | 4404 | 1984 | 13.8 | 69 | Easy | Medium | Few | Poor | Good | Fair |
Beech | 3760 | 27.5 | Difficult | Few | Excellent | Good | ||||
Birch | 4312 | 2992 | 20.8 | 104 | Medium | Medium | Few | Good | Slight | Fair |
Boxelder | 3589 | 2632 | 18.3 | 92 | Difficult | Medium | Few | Poor | Slight | Fair |
Buckeye, Horsechestnut | 4210 | 1984 | 13.8 | 69 | Medium | Low | Few | Poor | Slight | Fair |
Catalpa | 4560 | 2360 | 16.4 | 82 | Difficult | Medium | Few | Good | Bad | Fair |
Cedar, Red | 2060 | 13.0 | Easy | Low | Many | Poor | slight | Fair | ||
Cherry | 3696 | 2928 | 20.4 | 102 | Easy | Low | Few | Excellent | Excellent | Good |
Chestnut | 18.0 | Good | Good | |||||||
Coffeetree, Kentucky | 3872 | 3112 | 21.6 | 108 | Medium | Low | Few | Good | Good | Good |
Cottonwood | 4640 | 2272 | 15.8 | 79 | Easy | Medium | Few | Good | Slight | Fair |
Dogwood | 4230 | High | Difficult | Few | Fair | |||||
Douglas-fir | 3319 | 2970 | 20.7 | 103 | Easy | High | Few | Fair | Slight | Good |
Elm, American | 4456 | 2872 | 20.0 | 100 | Difficult | Medium | Few | Excellent | Good | Fair |
Elm, Siberian | 3800 | 3020 | 20.9 | 105 | Difficult | Medium | Few | Good | Fair | Fair |
Fir, White | 3585 | 2104 | 14.6 | 73 | Easy | Medium | Few | Poor | Slight | Fair |
Hackberry | 3984 | 3048 | 21.2 | 106 | Easy | Low | Few | Good | Slight | Good |
Hemlock | 2700 | 19.3 | Easy | Many | Poor | Good | ||||
Species | Weight (lbs./Cord) | Heat per Cord (Million BTUs) | % of Green Ash | Ease of Splitting | Smoke | Sparks | Coals | Fragrance | Overall Quality | |
Green | Dry | |||||||||
Honeylocust | 4640 | 3832 | 26.7 | 133 | Easy | Low | Few | Excellent | Slight | Excellent |
Juniper, Rocky Mountain | 3535 | 3150 | 21.8 | 109 | Medium | Medium | Many | Poor | Excellent | Fair |
Larch (Tamarack) | 3330 | 21.8 | Easy-med | Many | fair | Slight | Fair | |||
Locust, Black | 4616 | 4016 | 27.9 | 140 | Difficult | Low | Few | Excellent | Slight | Excellent |
Maple, Other | 4685 | 3680 | 25.5 | 128 | Easy | Low | Few | Excellent | Good | Excellent |
Maple, Silver | 3904 | 2752 | 19.0 | 95 | Medium | Low | Few | Excellent | Good | Fair |
Mulberry | 4712 | 3712 | 25.8 | 129 | Easy | Medium | Many | Excellent | Good | Excellent |
Oak, Bur | 4960 | 3768 | 26.2 | 131 | Easy | Low | Few | Excellent | Good | Excellent |
Oak, Gamble | 30.7 | |||||||||
Oak, Red | 4888 | 3528 | 24.6 | 123 | Medium | Low | Few | Excellent | Good | Excellent |
Oak, White | 5573 | 4200 | 29.1 | 146 | Medium | Low | Few | Excellent | Good | Excellent |
Osage-orange | 5120 | 4728 | 32.9 | 165 | Easy | Low | Many | Excellent | Excellent | Excellent |
Pine, Ponderosa | 3600 | 2336 | 16.2 | 81 | Easy | Medium | Many | Fair | Good | Fair |
Pine, Lodgepole | 2610 | 21.1 | Easy | Many | Fair | Good | Fair | |||
Pine, White | 2250 | 15.9 | Easy | Moderate | poor | Good | ||||
Pinon | 3000 | 27.1 | Easy | Many | ||||||
Poplar | 2080 | Low | Easy | Many | Fair | Bitter | ||||
Redcedar, Eastern | 2950 | 2632 | 18.2 | 91 | Medium | Medium | Many | Poor | Excellent | Fair |
Spruce | 2800 | 2240 | 15.5 | 78 | Easy | Medium | Many | Poor | Slight | Fair |
Spruce, Engleman | 2070 | 15.0 | 78 | Easy | Few | Poor | Slight | |||
Sycamore | 5096 | 2808 | 19.5 | 98 | Difficult | Medium | Few | Good | Slight | Good |
Walnut, Black | 4584 | 3192 | 22.2 | 111 | Easy | Low | Few | Good | Good | Excellent |
Willow | 4320 | 2540 | 17.6 | 88 | Easy | Low | Few | Poor | Slight | Poor |
Green weight is the weight of a cord of freshly cut wood before drying. Dry weight is the weight of a cord after air drying. Green firewood may contain 50% or more water by weight. Green wood produces less heat because heat must be used to boil off water before combustion can occur. Green wood also produces more smoke and creosote (material that deposits on inside walls of chimneys and may cause chimney fires) than dry wood. Firewood should therefore always be purchased dry or allowed to dry before burning. Dry wood may cost more than green wood because it produces more heat and is easier to handle.
A wood’s dry weight per volume, or density, is important because denser or heavier wood contains more heat per volume. Osage-orange is a very dense firewood with limited availability in Utah. It’s included here to show what a very dense wood is like. It contains almost twice the heat by volume of cottonwood, one of our lightest woods. In general it is best to buy or gather dense woods such as oak, hard maple, or ash. Hardwoods, or woods from broadleaved trees, tend to be denser than softwoods or woods from conifers. Some firewood dealers sell “mixed hardwood” firewood. This may or may not be desirable, depending on the proportion of low- density hardwoods such as cottonwood that are included.
The amount of heat per cord of dry wood is presented in the table above. Heat content is shown as a percent of dry green ash, a fairly common, dense firewood. Values above 100 signify a higher heat content than green ash and below 100 a lower heat content.
The information above also contains information on other characteristics that determine firewood quality. Ease of splitting is important because larger pieces of wood must usually be split for good drying and burning. Fragrance and tendency to smoke and spark are most important when wood is burned in a fireplace. Woods that spark or pop can throw embers out of an open fireplace and cause a fire danger. Conifers tend to do this more because of their high resin content. Woods that form coals are good to use in wood stoves because they allow a fire to be carried overnight effectively.