You only can run 20' horizontal which is the problem. We are actually above ground (full walkout basement) but if we run to the side we vent right outside french doors and onto a porch which has a masonry patio above. There is a box bay for the guest bedroom immediately to the side so we can't go there. We are just a little too far away to run straight back over the guest bedroom because of 6" stud walls and 3" or so of brick . . . My builder is getting conflicting reports from fireplace salespeople about whether a b vent will work. The Isokern folks say theirs will, but the fireplace store says all the ones we have found (which frankly seem to have similar venting requirements to the isokern but just cost less) won't work. The isokern salesperson is saying something about how their system has less heat or something? I can't find anything about that and frankly it concerns me because the other fireplace store's technical guru is finding problems with the b vent installation . . .

We're planning to put a Montebello See though direct vent on our Deck wall (backing to the interior family room). As renovator said they make an indoor/outdoor one that while pricey, is designed for just that application. There are actually a number of brands that now have this, Heat n Glo, Majestic, Montessan. Speaking from my in person experience of the Montebello showroom model, the outdoor side with the outdoor window kit (which makes this useable on an outside wall) is more for ambience not heating. We could really feel the heat radiating off the ceramic interior face of the FP but when we popped outside to check out the view of it burning didn't feel much heat at all. It hadn't been running too long however. Might still work well for supplying heat to a screened in porch if the area is left open to the interior side of the FP which it sounds like wouldn't be too hard to do in your application.

We have a blower on our DV gas insert, not a Lennox, but we haven't used it yet. At slow speed, it's not too noisy, but I would not want to use it at high speed. A word about using a ceiling fan. Some fans are equipped with a switch that reverses the direction of the turning. In that case, instead of blowing DOWN to cool you in warm weather, it blows UP, so that you don't feel an objectionable breeze in winter, but the warm air is more even distributed throughout the space. As an alternative to a reversible motor, some fans are designed so that the blades can be repositioned (You twist them) so that they achieve the same effect as a motor reversal. Although we haven't used our blower here in North Carolina, I think we probably will try it next winter because these DV unit put out a lot of heat, and you don't want it concentrated in just one area -- you want to distribute it. I would also strongly recommend a hand held remote control thermostat. Once you figure out how best to use it -- where in the room it's best to put it, and what temp setting is best -- you will get a more even, comfortable temperature in your space. Otherwise, you'll be turning it off periodically because they put out heat like a blast furnace, and they can get really hot.

I'm very happy with the Montigo. Ours was just actually hooked up correctly very recently so we've only been using it a couple of weeks. We still don't have our stonework done, so it doesn't look that great. I'm hoping to finalize that stone very soon! Edited to add a picture I had. Again, pretty basic with no stone and just sheetrock but you can see the brick, logset and flame.