weight of pellets for a given volume?

40 lbs per cubic foot

wi-dogfish said:

I would like to take a trailer and fill it full of softwood pellets . It's 5' x 8' x 22" tall. Can someone please tell me how much this load will weigh. Or just how much a cubic foot of pellets will weigh?

Thank you very much.

I've done some searching and couldn't find anything.

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Are you talking about filling it with loose pellets, or 40lb. bags?

The pellets alone in that trailer, if they were loose and filled to the brim, would weigh 1 1/2 tons. Better make sure the Gross trailer weight can handle that plus the weight of the trailer too.

Loose pellets weigh 40 pounds per cubic foot.

"Typical" bagged pellets weigh roughly 32 pounds per cubic foot.

For a rough physical approximation, a ton of pellet will occupy a 4x4x3 space loose, or a 4x4x4 cube bagged.

Joe

According to the Pellet Fuels Institute, PFI graded pellets must weigh a "minimum 40 pounds/cubic foot".

Here's the link to the source: http://www.pelletheat.org/3/industry/index.html

A cubic foot is an Imperial (non-metric) unit of defined volume (equivalent to a cube 1 foot - or .3048 meters - on a side) and does not change based on the container (or lack thereof).

DiggerJim said:

A cubic foot is an Imperial (non-metric) unit of defined volume (equivalent to a cube 1 foot - or .3048 meters - on a side) and does not change based on the container (or lack thereof).

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Bagged pellets take up more space, because there are air gaps between the multiple 40-pound or 15-kg bags (the two most common sizes).

Joe

BrownianHeatingTech said:

Bagged pellets take up more space, because there are air gaps between the multiple 40-pound or 15-kg bags (the two most common sizes).

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Guess I better call my pellet guy - I've got 3 pallets of pellets (Barefoot and Hamer) which are supposed to be 1 ton each and they do have 50 40-lb bags each but they're only 4 ft x 3.5 ft x 43 in. (a hair over 50 cu ft). They must have shorted the bags. Or maybe Stanley shorted my tape measure.

Or maybe under the compressive force of a ton of weight, the bags squeeze into the air gaps and 20% of the space is not air after all. This pellet stuff is *so* confusing.

DiggerJim said:

Guess I better call my pellet guy - I've got 3 pallets of pellets (Barefoot and Hamer) which are supposed to be 1 ton each and they do have 50 40-lb bags each but they're only 4 ft x 3.5 ft x 43 in. (a hair over 50 cu ft). They must have shorted the bags. Or maybe Stanley shorted my tape measure.

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Guess you should. Probably also should check your pellets, as they may be over-dense. I've measured a lot of stacks of pellets, and they've never packed down to the same density as loose pellets - physics prevents it.

DiggerJim said:

Or maybe under the compressive force of a ton of weight, the bags squeeze into the air gaps and 20% of the space is not air after all. This pellet stuff is *so* confusing.

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The compressive force varies with the depth. The top bag is under none. Even the bottom bag is under only the weight of a few bags of pellets (whatever is vertically above it), not one ton of force.

Joe

I guess my tape measure must be off then. Should teach me to trust my own eyes.

Looks like Shortstuff in this thread (https://www.hearth.com/econtent/index.php/forums/viewthread/22987/) has the same problem measuring as his stacks also come out way small for 32lbs/cu ft bagged too. Seems more consistent with the advertised 40lbs/cu ft, but hey, YMMV as they say.