I burned buckwheat early in the season (oct-nov) and seemed to go through more than I had hoped with warmer temps outside. Once it got cold in December it seemed to burn more efficiently. I changed remainder of my coal order (3 tons) to rice because of my early season experiences with the buckwheat and now wished I hadn't. I seemed to be filling the hopper more with the rice when the outside temps were pretty steady. Next year I am going to try rice in fall and spring and buckwheat though the winter.
Of course i have no scientific evidence to back up my statements, just my experiences.
I am on track to burn 5 ton this year. 2 of buckwheat and 3 of rice (1650 sqft well-insulated raised ranch)
Please show install photos, fellow AK110er.