Pellets have a certain amount of moisture built into them when manufactured. They tell you to store them in a dry moisture free area. But after being stored for several years in cool dry area, is it possible that the moisture content in the pellets could drop lower than the moisture content at time of manufacturing, and change the way they burn.
Are they burning cooler, or hotter? Only ask because we've been burning 2 yr. old stock stored outside in the woodshed (roofed, and stored at the back & dry, but exposed to outside air), and we've been opening them inside / letting them 'air out' for a few days before roasting.. They've been burning good. Just curious.
I have had some 3-4 yrs old that were stored in a detached garage. I noted condensation on the bags from time to time, but to honest, they burned just the same as when I first bought them.
The moisture content is usually 5% - much dryer than wood can naturally get by air-drying (or "seasoning"). They won't get any dryer but they can absorb moisture and become wet if they come into contact with water. Humidity in the air doesn't seem to affect them.
yea, keep em dry, youre good. You can get a little exfoliation off of the individual pellets, and likely you'll see an increased moisture content, but not likely enough to make a difference. The more moisture there is will eat into the BTU output (it takes BTU's to drive off moisture). I ve a damp basement, and have had pellets have birthdays down there, to no ill effects!
Thanks, will keep them high & dry here LW. Good to know they can celebrate Birthdays w/ no ill effects, I'll buy them a Beer.
We woodworkers know all about this. Google EMC (Equilibrium Moisture Content) Its what makes Aunt Bessy's 200 yr old China Hutch from Arizona have sticky doors when you move it to Florida in the summer. Ambient moisture in the surrounding air causes wood cells to shrink/expand with moisture. The USDA Forest Products Lab has a Book on all things wood. https://www.fpl.fs.fed.us/documnts/fplgtr/fpl_gtr190.pdf In particular Chaper 4. Moisture in wood. I harvest my own turning stock from local standing trees. Logs or timbers have two types of moisture. Free Moisture.....what is contained between the cells of the wood. And, Bound Moisture...what is contained within the cells. Free Moisture flashes off fairly quickly once timber is cut Bound Moisture takes quite a while to dry to ambient. General rule of thumb is 1" per year. The trick to drying timber is you want to do it slowly and evenly to prevent cracks (checking) Pellets being heavily processed sawdust won't suffer much from Free moisture unless they get soaked or submerged. But they will contain Bound moisture as any wood will. The storage of pellets will affect how much ambient moisture they absorb/release. There is also a bit of "Case Hardening" on molded pellets and this will affect the absorption rates. How much I'm not sure. The plastic storage bags will go a long way to reducing quick changes but in long term storage it wont make any difference. Just like the varnish on Aunt Bessy's Cabinet. It basically comes down to surface area exposed. I would guess (My guess) the 1"/year general rule of thumb also applies to bagged pellets The pellet storage bags and the actual pellet surface will determine how much moisture is absorbed/expelled So bagged pellets with several years of damp basement storage will have been affected ~2"-3" on all exposed sides. Perhaps more depending on how tight they are stacked on the pallet. So Back to original question...... Yes, Pellets stored in dry cool basement could have lower moisture content then when they were manufactured. ---Nailer---
My LaCrete have been in the basement for over 2 years now and they are right next to the stove-so very dry in the winter and a bit humid in the summer. No ill effects at all.
I have pellets easily a few years old, they're like a fine wine (or woman).....treat it right and it gets better with age
my skids of pellets are about 10 feet away from our oil furnace that kicks on quite a few times per 24 hrs for domestic hot water. prob helps keep them dry.
