Good morning everyone , -2 in southern Maine this Am . I've had a Hampton 300 free standing stove for a little over a year now & was wondering if I should be getting longer burn times . The manufacturer says it's a large stove but it only has a 1.7 cubic foot firebox . I have clean , dry firewood but I'm hesitant to close off the air input to much . I have a stack thermometer that runs about 400 to 450 degree's when I reduce the air inlet after the fire is established . I will get about 3 hours of burn time before I need to add more wood . Is this typical for this stove ? Thanks for any help ........