Do some pressed wood products burn hotter or longer than others? Attached is a spreadsheet to help give a rough idea so you can plug in your own favorite/or not supplier and look at the numbers 
I am very skeptical of any claims of BTUs per pound unless I see a real independent analysis of product. Some pressed product claims are dubious or meaningless, politely put. I included a place for this information in my spreadsheet for giggles. There were some recent discussion about Canawick and Northern Idaho Energy products, so I used them for my initial spreadsheet data and discussion here. There are lots of products.
What does "Hotter" mean? It could mean something that contain more BTUs per volume than something else. When I fill up my firebox with pressed wood, I get 1/3 to 2 times the number of BTUs in the same space than with wood chunks. However, somebody else might say that a round log (chunk wood) split into very small pieces. burns hotter than one which is not spit. Here we are talking about how fast the same number of BTUs are released over time. Thus I am always confused when people talk about "hotter", especially when it is a wood product salesperson.
My burn time theory says the less surface area per pound of product the longer the burn time. Burn time is very important in a semi airtight stove or open fireplace. It is less important in stove or furnance where the air to the fire box is controlled automatically. I will let others debate if a faster buring fire is hotter and a slower burning fire colder
Getting an rough compairson of burn times is about the math. The lower the pound to surface area ratio, the longer the burn. I set up a spreadsheet and took two manufactures website analysis, and used their numbers. A Canawick brick (2 lbs) is 2.5 x 3.75 x 6.0 which is 71.25 sq inches of surface area. A Canawick block (6 lb) is 4 x 4x 10.5 or 158 sq. inches. A Northern Idaho Energy Log (8 lbs) is round and 4 inches in diameter by 13 inches in lenghth or 188 sq inches of surface area. I created an imaginary cube (10.5 lbs) 6 x 6 x 6 or 216 sq inches of surface area.
The bricks have a 35.6 sq inches of surface area for each pound, the block ratio is 26.3, the log ratio 23.6. and the cube was 17.1 . While the burn time probably does not have a 1 to 1 relationship to initial surface, I think this ratio will give you a good idea.
I conclude that all things being equal, my imaginary cube, or the NIE log would be my choice for fire place or in a stove where the air is adjusted manually and I wanted to streach out the burn time. For my almost air tight wood gasification boiler, I selected the bricks.
My spreadsheet computed a a ratio of surface area to stated BTUs per pound and multiplied that by 100,000. I did that just because I could. Frankly I don't believe NIE nor Canawick is comparing BUTs "apples to apples". For example last year, a third company shared their independent test results with me which clearly said their product had 6.7% moisture and 8213 BTUs per pound, but they used the Dry Basis of 8803 BTUs on their packaging.
My spreadsheet also looks at density (weight divided by cubic measure). Apparently the Northern Idaho Energy product is .049 and Canawick .036, NIE is more dense by a 1/3 according to these figures.
Recap: how long a wood product burns depends upon a lot of variables involving stoves. Manufacturers (or chunk wood suppliers for that matter) do not post their independent lab analysis of the exact size, weight, moisture content and BTUs in an average sample of their product. Consider this spreadsheet as another brush in your toolbox, when you are tying to paint the ideal fuel for you.
Good luck and be sure to have fun.
I am very skeptical of any claims of BTUs per pound unless I see a real independent analysis of product. Some pressed product claims are dubious or meaningless, politely put. I included a place for this information in my spreadsheet for giggles. There were some recent discussion about Canawick and Northern Idaho Energy products, so I used them for my initial spreadsheet data and discussion here. There are lots of products.
What does "Hotter" mean? It could mean something that contain more BTUs per volume than something else. When I fill up my firebox with pressed wood, I get 1/3 to 2 times the number of BTUs in the same space than with wood chunks. However, somebody else might say that a round log (chunk wood) split into very small pieces. burns hotter than one which is not spit. Here we are talking about how fast the same number of BTUs are released over time. Thus I am always confused when people talk about "hotter", especially when it is a wood product salesperson.
My burn time theory says the less surface area per pound of product the longer the burn time. Burn time is very important in a semi airtight stove or open fireplace. It is less important in stove or furnance where the air to the fire box is controlled automatically. I will let others debate if a faster buring fire is hotter and a slower burning fire colder
Getting an rough compairson of burn times is about the math. The lower the pound to surface area ratio, the longer the burn. I set up a spreadsheet and took two manufactures website analysis, and used their numbers. A Canawick brick (2 lbs) is 2.5 x 3.75 x 6.0 which is 71.25 sq inches of surface area. A Canawick block (6 lb) is 4 x 4x 10.5 or 158 sq. inches. A Northern Idaho Energy Log (8 lbs) is round and 4 inches in diameter by 13 inches in lenghth or 188 sq inches of surface area. I created an imaginary cube (10.5 lbs) 6 x 6 x 6 or 216 sq inches of surface area.
The bricks have a 35.6 sq inches of surface area for each pound, the block ratio is 26.3, the log ratio 23.6. and the cube was 17.1 . While the burn time probably does not have a 1 to 1 relationship to initial surface, I think this ratio will give you a good idea.
I conclude that all things being equal, my imaginary cube, or the NIE log would be my choice for fire place or in a stove where the air is adjusted manually and I wanted to streach out the burn time. For my almost air tight wood gasification boiler, I selected the bricks.
My spreadsheet computed a a ratio of surface area to stated BTUs per pound and multiplied that by 100,000. I did that just because I could. Frankly I don't believe NIE nor Canawick is comparing BUTs "apples to apples". For example last year, a third company shared their independent test results with me which clearly said their product had 6.7% moisture and 8213 BTUs per pound, but they used the Dry Basis of 8803 BTUs on their packaging.
My spreadsheet also looks at density (weight divided by cubic measure). Apparently the Northern Idaho Energy product is .049 and Canawick .036, NIE is more dense by a 1/3 according to these figures.
Recap: how long a wood product burns depends upon a lot of variables involving stoves. Manufacturers (or chunk wood suppliers for that matter) do not post their independent lab analysis of the exact size, weight, moisture content and BTUs in an average sample of their product. Consider this spreadsheet as another brush in your toolbox, when you are tying to paint the ideal fuel for you.
Good luck and be sure to have fun.
