Scandinavian HWAM fires have a heat sensitive spring that auto regulates the amount of air going into the combustion chamber of the fire, so that you continually get optimised buring of the wood:

• More heat from the same amount of wood
• Less ash
• Less hassle
• Less soot on the glass.

Video that shows the auto system (jump to 1 minute in !).

Above picture of the HWAM I30/55 that has the Nordic Ecolabel. For more info see

http://hwam.com/products/insert+selection/hwam+i+3055

Fire Heat Storage / Thermal Store

Create a thermal mass, with the chimney around the fire, so that post the fire dying out heat is slowly released into the room.

HWAM have a page on their soapstone system at http://hwam.com/hwam+advantages/heat+storage

UK HWAM Distributors:

• http://www.euroheat.co.uk/Wood-Burning-Inserts/Hwam-I-3055-Insert-Wood-Black.html – £2224.00 excl VAT, £2668.80 incl VAT (new build projects get VAT back / don’t pay VAT)
• http://www.stovesandcasts.co.uk/hwam-i-30-55-insert-wood-burner.html
• http://www.woodburningstovesco.co.uk/EZ/wbs/wbs/prod_hwam_i_30_55_6kw.php?PHPSESSID=p7tk1v30mu2i5uvvvqjjr7v9d4&model=38
• http://www.gscstoves.co.uk/index.php?page=shop.product_details&flypage=flypage-ask.tpl&product_id=395&category_id=27&option=com_virtuemart&Itemid=29&vmcchk=1&Itemid=29 for £2,159.52