Softwood pellets do not burn any faster than hardwood pellets in a pellet heater. Likewise, hardwood pellets do not burn slower or longer than softwood pellets. I’ve mentioned this elsewhere on my website but this view of softwood vs hardwood does not apply to pellet heaters. This conception that hardwood pellets are better or softwood pellets are better doesn’t apply to pellet heaters. If you own a wood heater, than at least in Tasmania you want to burn hardwood and not softwood. But that’s for wood heaters, NOT pellet heaters.
The short version is wood material used to create wood pellets, be it softwood, hardwood or any combination of the two, is compressed during making wood pellets so that a kilogram of softwood pellets contains about the same energy (heat) as hardwood pellets. There may be minor differences between softwood and hardwood pellets in terms of ash left over once burnt, but they basically contain the same heat and thus don’t burn any longer or slower.
Firewood Misconceptions
As I mentioned above, this softwood vs hardwood pellets issue comes from wood heaters. In Australia people burn hardwood because it burns longer and generally doesn’t burn as hot as softwood, which can damage some wood heaters. If you’ve ever owned a wood heater and handled firewood, then you’ll know that the density or weight of firewood will vary depending on the species, even between different types of hardwood. Heavier wood is denser and burns longer. I personally think this is where all this hardwood vs softwood stems from. But it doesn’t apply to pellet heaters.
How Pellets are Made
I’ve written about how wood pellets are made on this site, so read that if you want, otherwise here’s the short version. Waste wood material is screened to remove rocks and other rubbish, it’s crushed down to size, dried so it’s the right moisture content and then compressed into pellets. Once compressed the pellets cool down and then are usually packed in plastic bags. It’s the last step, compressing wood into pellets, which is key here and why old firewood views on softwood vs hardwood don’t apply to pellet heaters.
The density of softwood, hardwood and species within these two types of firewood varies. It’s this density that results in some hardwood burning longer than softwood. However, that only applies to firewood. Wood waste is compressed when making wood pellets and it’s compressed so tight that there’s almost no difference between the two in terms of how much heat or energy they contain. So a 15kg bag of softwood pellets will last just as long as a 15kg bag of hardwood pellets. What will change how long a bag of pellets last is if you run your pellet heater on high, low or medium, not the type of wood used to make them.
So There’s No Difference?
In terms of how long wood pellets last, it won’t matter if you buy hardwood, softwood or a 50/50 mixture of both types of wood that you sometimes see. What you may notice is that there may be slightly more ash or clinkers with one brand instead of another. Is this caused by the pellets being softwood or hardwood? I’ve written about wood pellet clinkers in pellet heaters before and while some people prefer softwood because they have less ash, I don’t think this is something anyone should worry about.
Wood pellet quality is MUCH more important than the type of wood (softwood or hardwood) used to make the wood pellets. I’ve seen hardwood pellets, which some people say don’t burn clean and produce clinkers, burn much better than softwood pellets. The reason for this is he quality of the raw material used to make the wood pellets. So, don’t worry about what type of wood was used to make your pellets, buy pellets that are priced reasonably for you and burn well in your heater.
Summary
Pellet heaters aren’t wood heaters. Softwood pellets do not burn quicker than hardwood and hardwood pellets do not burn slower than softwood pellets. This softwood vs hardwood is a hang over from firewood days but doesn’t apply to pellet heaters. Instead of fussing over the type of wood used and especially if you are looking to buy a pellet heater for the first time, I recommend you burn pellets that are affordable for you and burn well in your heater.
Resources:
Heating values of wood pellets from different species website
