Should you worry hardwood vs softwood pellets when it comes to getting the most out your pellet heater? Unlike firewood, wood pellets, regardless of species of wood used generally produce similar amounts of heat. You will find some slight variation in heat (about 10%) as softwood typically burns hotter but for the most part you should worry more about the price of pellets and pellet quality. Both softwood and hardwood pellets can burn poorly and leave large amounts of ash and clinkers if they are made from wood waste that is of poor quality, so focus on quality and not hardwood of softwood. The reason wood pellets produce similar amounts of heat has to do with how they are made.
Here’s the short version on why it doesn’t really matter if you burn hardwood or softwood pellets:
- The process of making pellets results in basically the same amount of “heat” stored within hardwood and softwood pellets.
- Hardwood vs softwood is a spill over from wood heaters and firewood. It is not relevant to pellet heaters or wood pellets.
- Pellets made from wood waste that is impure (lots of bark for example) will burn poorly regardless if its hardwood or softwood.
- Focus on pellet quality and bang for buck. Buy a few bags and see how they burn in your heater and compare costs.
How Wood Pellets are Made and Heat Content
The process of creating wood pellets, also known as the pelletization process of wood pellets, involves several stages that result in a similar heat content regardless of the type of wood used, be it softwood or hardwood. While it’s definitely true that generally speaking softwood does burn hotter overall than hardwood, the difference is minimal due to how pellets are made and the reality is most people probably wouldn’t notice the difference nor be able to tell if the pellets in a pellet heater currently being burnt are hardwood or softwood based on how warm the room was. In fact, the whole hardwood vs softwood stems from wood heater days and firewood and has carried over into pellet heaters.
The process of making hardwood and softwood pellets is the same and begins by breaking down the wood material or waste wood that is used to create pellets into smaller pieces, then filtering it to remove impurities, such as rocks and anything similar that won’t burn. After this, the wood material is dried to bring moisture content down and compressed into pellet form, which gives wood pellets their consistent and reliable heat output. Compare this to firewood where firewood varies greatly in heat output due to the different types of wood people burn and moisture content because some people burn green firewood. The process of pelletization ensures that wood pellets produce consistent heat, regardless of the type of wood used.
Hardwood and Softwood Pellet Quality
When deciding on which wood pellets to buy and burn in your pellet heater, I think it is more important to focus on the quality of the pellets rather than getting caught up in the hardwood versus softwood debate and worrying about which one may or may not burn hotter, cleaner or better. The quality of the wood pellets you burn can have a significant impact on how efficiently your pellet heater runs, the amount of heat it puts out, and ultimately, the cost of operating it.
How well or “clean” wood pellets burn is an important thing to consider when it comes to deciding on which pellets to burn. Pellets that contain impurities, such as waste wood from pallets that weren’t screened properly and contain things like glue or chemical residue, obviously won’t burn as well as well as higher-quality pellets made from sawdust left over from cutting wood into timber. The much higher quality pellet will produce more heat due to containing fewer impurities. Furthermore, wood pellets that contain a lot of impurities will most likely produce much more ash, clinkers and you’ll need to clean your pellet heater and flue more often to keep it running efficiently.
Another thing to be aware of is the length of the wood pellets. Wood pellets that are too short or too long can have a huge impact on how your pellet heater burns. Short pellets are fed into the burn pot faster, creating more heat and you’ll go through a bag of short pellets faster costing you more money. In contrast, long pellets will be fed slower through the auger into the burn pot, which does the opposite and creates a smaller fire, producing less heat and while you’ll burn fewer wood pellets saving money you won’t get a consistent burn and very long pellets can jam in the auger in the pellet heater. You want to avoid long pellets.
What Type of Wood Pellets Can I Burn in My Pellet Heater?
You can burn both hardwood pellets, softwood pellets or a mixture of the two in any pellet heater. You might see that manuals for some pellet heaters recommend burning softwood or hardwood but it doesn’t matter. I know that some people with Piazzetta pellet heaters may prefer to burn pellets with less ash, but you can burn either type of pellet in European luxury heaters or more budget friendly Chinese pellet heaters. However, you should only burn pellets made from hardwood or softwood. Most pellet heaters in Australia are not multi-fuel burners which can burn grain and other type of fuels. Stick with wood pellets only.
Instead of worrying about softwood vs hardwood pellets I strongly recommend you focus on the actual quality of the pellets. Poor quality pellets will, if the heater isn’t cleaned and looked after, cause major problems and restrict airflow in any pellet heater. By that I do mean any brand. It doesn’t matter how much you spent on your pellet heater, if you burn poor quality pellets and do not adjust your cleaning and servicing to deal with this extra ash build up, you will have problems. The same goes for long pellets. Super long pellets can potentially jam the auger in any pellet heater. Expensive European pellet heaters are not immune to auger jams.
How to Check Hardwood and Softwood Quality
While there’s no way to know how good or bad a bag of pellets burns before you actually burn them, here’s a few tips on how to ensure you try and make sure you get the best quality pellet you can. The colour of wood pellets can range from light to dark brown. Softwood pellets are generally lighter in colour then hardwood. However, colour may also vary depending if any binders, like vegetable, were used when making the pellets. Besides colour, check pellet length. All you need to do is look at the bag of pellets. What’s the overall length of pellets visible inside the bag look like? Do they look too short, medium or long in length?
Pellets that all very short will burn faster. This isn’t necessarily bad but something you may need to be aware of. What you are really want to avoid is very long pellets. If all the wood pellets appear to be 4 cm and longer with no short to medium pellets, then it will mean there could be problems with the feed rate of pellets into your burn pot. Again, it doesn’t matter if they are softwood or hardwood pellets. Focus on the length of the pellets and try and avoid bags of pellets that contain only very long ones.
The above becomes second nature after you’ve done it a few times. You’ll know to quickly check pellet length and while pellet colour (light to dark brown) doesn’t always indicate quality it does at least give you an idea of the type (hardwood vs softwood) pellet that you are burning. If a retailer is trying to sell you a bag of 100% softwood pellets but the pellets are dark brown, then it’s possible the pellet mill used a binder or they contain impurities. This means they may burn very well in your heater and may not be worth the higher price softwood pellets usually sell for.
Hardwood and Softwood Pellet Prices
Generally speaking, hardwood and softwood pellet prices vary quite a lot. Hardwood in Tasmania costs about $9.50 a bag and softwood $13.00. This is why I say focus on quality and price because why buy softwood pellets if they are expensive and mean you can’t run your pellet heater as often as you would like. Looking to try some new pellets? Get a few bags and test them out. Keep an eye on pellet length, you don’t want them too short, nor do you want them too long. What you pay for pellets directly impacts how much it costs to run your pellet heater, so it’s worth spending time hunting for the best price on pellets you can find.
Also, when you empty out the burn pot and clean the burn chamber, check to see if you are getting clinkers and how much ash there is. Excessive clinker build-up and ash “may” be an indication of a poor-quality pellet. This isn’t always the case as a pellet heater that hasn’t been looked after, cleaned, and serviced won’t burn properly and can result in clinkers forming, but excessive clinkers and ash is one indication of pellet quality assuming the heater has been serviced and looked after.
Summary
So what’s the verdict? I say don’t worry about the differences, perceived or real, between hardwood vs softwood pellets. Price and quality should be more important, especially for people new to pellet heaters. Remember to check out the wood pellets Australia post if you are trying to find a better price on pellets or are considering buying a pellet heater and want to know what you’ll pay for wood pellets in your area.
Resources
I’m sure some people are screaming at how wrong I am here. I don’t disagree, softwood pellets in a perfect world burn hotter however it is minimal and I still think price and quality is more important. The abstract of the research paper below shows that on average and at most softwood pellets have about 10% more heat than hardwood. Which is why think most people should focus on price and quality before worrying about type of wood their pellets are made from.
Heating values of wood pellets from different species
