Hardwood vs. Softwood: Which Firewood is Better to Burn?

Getting the best possible wood heating experience often comes down to the type of wood heating appliance you buy. But an important (and often overlooked) aspect of wood heating has to do with the kind of firewood you burn in your fire pit, wood stove, or wood furnace.

This topic can get very specific very quickly, as firewood types vary from region to region (and even state to state). In the United States, for example, there are around 90 different species of oak alone. This is why it’s helpful to bunch firewood into two broad categories: hardwoods and softwoods.

You may have heard these terms before. But what do they mean? What are the key differences between them? And which one is better to burn?

Well, at HY-C, we know firewood pretty well. We manufacture EPA-approved forced-air wood furnaces, and getting a wood burning furnace through the EPA testing process requires a deep understanding of cordwood fuel. In this guide, we want to share some of what we’ve learned with you.

We’re going to cover some of the major differences between hardwood and softwood. We’ll take a look at how easy (or difficult) it is to split each type of wood, what it’s like to light each type, how much heat they both tend to put off, and the combustion byproducts each type gives off.

By the time you’re finished here, you’ll know whether or not burning hardwood or softwood is right for your specific wood burning application.

Hardwood and Softwood: General Characteristics

Before diving into the different burning tendencies of hardwoods and softwoods, let’s take a quick look at how each type is categorized in the first place.

While hardwoods tend to be denser than softwoods, surprisingly, that’s not where they get their names. Whether a wood is “hard” or “soft” is determined by whether or not the tree's seeds are angiosperms (seeds with a protective covering) or gymnosperms (seeds that are exposed to the elements).

With that in mind, softwoods come from coniferous trees like evergreens. This means they have needles and pinecones that make them easily identifiable at a quick glance. Softwoods also tend to have a higher resin content than hardwoods.

By contrast, hardwoods come from deciduous trees. These are the kinds of trees that generally shed their leaves every fall. Hardwood tree species tend to grow more slowly than softwood species, making their wood stronger and more durable.

Hardwood vs. Softwood

Now, let’s start looking at hardwood and softwood in terms of what it’s like to use each one for firewood. To do this, we’ll use data from Utah State University to consider some differences between three hardwoods (red oak, cherry, and silver maple) and three softwoods (ponderosa pine, spruce, and white fir).

We’ll compare these hardwoods and softwoods along four fronts:

1. Ease of splitting
2. Ease of lighting
3. Heat output
4. Combustion byproducts

1. Ease of Splitting

So, which is easier to split for firewood — hardwoods or softwoods?

The Utah State University data shows that hardwoods tend to be more difficult to split. This is because they are often denser than softwoods, requiring more effort to cut. Their complex, varied grain patterns also make them tough to split. Hardwood grains are often made up of curly, burled patterns that take a lot of effort to split apart.

Softwoods, on the other hand, tend to have straight (or just slightly wavy) grain patterns. Ax heads tend to follow these grain patterns down the log, reducing resistance and making splitting much easier. Softwoods are also less dense than hardwoods on the whole, making them easy to cut through.

2. Ease of Lighting

When it comes to actually getting the firewood lit, softwood is easier to ignite than hardwood for three reasons: resin, porosity, and density.

Because softwood comes from coniferous trees, it tends to have more resin in it than hardwood. Resin is a very flammable substance, and its presence in softwood makes it much easier to light.

Softwood also tends to be more porous than hardwood — that is, it has many small, open holes throughout it. These holes allow oxygen to flow through the firewood, helping to get (and keep) the fire going.

Finally, softwood is less dense than hardwood. The denser a piece of cordwood is, the more energy it takes to light it on fire. Softwood’s lower density means there’s less material to combust in the first place, making it easier to get alight.

3. Heat Output

Softwood may be easy to split and easy to light, but hardwood puts off more heat than softwood (on the whole). Why is that?

For one, they have more heat energy inside of them to begin with in terms of British Thermal Units (BTUs). Looking back at our species comparison, the hardwoods on the list average 21.3 million BTUs per cord of wood burned. The softwoods, on the other hand, average 15.4 million BTUs per cord.

While hardwood’s higher density is what makes it more difficult to light in the first place, it’s also what allows it to put off more heat. There’s more material there, and when that material is burned, it puts off more heat.

Also, hardwood tends to have a lower moisture content than softwood (especially when the wood is seasoned properly). Moisture in wood saps away heating energy because that energy winds up having to boil the moisture away (rather than being radiated as heat).

4. Combustion Byproducts

From a safety perspective, wood that produces less smoke is better to use, and hardwood typically gives off much less smoke than softwood.

When you’re burning wood in a wood stove or a wood furnace, smoke travels up the chimney flue. As that smoke rises and cools, it can transform into creosote — a sticky, tar-like substance that is highly flammable. Creosote is by far the leading cause of chimney fires.

Softwood produces quite a bit of smoke (especially relative to hardwood species) due to its high resin contents and its comparatively high moisture contents. This means if you’re burning hardwood in a stove or furnace, it’s much more likely to produce smoke (and creosote).

Hardwood vs. Softwood: Which Wood Should You Burn?

We’ve compared hardwood and softwood in terms of their ease of splitting, ease of lighting, heat output, and combustion byproducts. But which of these two wood types should you burn?

If you’re burning an open-air fire (like a campfire or a fire in a backyard fire pit), softwood is a good choice. It’s easy to light, and because the fire is out in the open, its higher smoke yield tends not to be as much of an issue (as long as you don’t breathe it in).

If you’re burning wood in a wood burning furnace or wood stove, though, hardwood is your best option. Not only does it put out more heat, but its low smoke output is much safer to use in an enclosed chimney system, resulting in less creosote and less of a chance of a chimney fire.

Most of the time, though, the wood you use simply comes down to what’s available in your area. To compare different types of firewood, our guide to the best firewood covers several species to help you find the right one to use for your wood burning application.