I would like to purchase a combination wood/oil furnace. I only have 1 chimney with an 8x13 tile flue. According to yukon/eagle I only need 1 flu for their furnace where as others state that I need two? Why would I only need one for the yukon/eagle but two for other brands of furnaces? Is there a risk of venting through 1 flu? Also, I like the yukon/eagle furnace but have not found any reviews outside of their website? Are they a reliable company? Do you know where I can find reviews about them? Do you know of other combination wood/oil furnace manufacturers that are reputable?