I live in a small 850sf single floor country home in the mountains of WNC with an old fuel oil furnace. Since I have piles of firewood left over after the storm Helen, it was a no-brainer to purchase an install a small wood stove for less than the cost of 200 gallons of fuel oil. The Drolet Spark II fit the bill and heats my whole house now. I'm a retired building contractor who demands quality and superior design and function. Your product has exceeded my expectations and the tech guys were always helpful. I highly recommend Drolet products and the Vortex Double Wall vent pipe is the only way to go. Thanks for a great product and service after the sale.