Thanks for your input, Renovator8. That fireplace has been through a few transitions. It was first an Isokern masonry like fireplace but to save some money we changed it to a b-vent on the plans. Once we placed the house on the lot, it became apparent that the b-vent pipe would be viewable from the street, and would have to be fairly high due to the slope of the roof. The initial hope was to hide the b/vent pipe from view behind the upstairs Isokern chimney, but the house is oriented in a way that it is viewable on approach, even though not seen in the front or back yard. We then changed to an direct vent. The whole reason for the direct vent was to not vent to the roof, so I would like to avoid that. We have a couple of options with the Montebello like running them behind a bookshelf in the dead space and then over a boxed bay bumpout, but the pipe is so big it may make it not feasible. I don't think we have enough rise available to run it over the master bedroom tray ceiling above, unfortunately, because that will vent out the side of a house above the a/c in a very inconspicuous place.

"...the Northern region...." and "..cold winters...." are not very specific. To people in Florida, Virginia has cold winters. Additional information about climate and your gas and electric rates would be useful in advising you.

I don't know where the middle window was. Still not sure where the vent is either. The right side of the porch shows 5 windows on that wall. The middle window no longer exists. It's a wall with the range hood on the other side. Directly above it, about four feet from the exterior wall, and about two feet below the ridge, the vent exits the porch roof. (not far from where the triangle shows the roof pitch on the second drawing). But if the sheetrock is up and painted, your ship has sailed, because nobody is going to want to open up the sheetrock and repaint to fix something they don't think needs fixing. If there were a good fix, I'd do it on my dime. It would be worth it to me. The volume of air you exhaust and the relatively low odor of most foods I don't think is an issue. If this wasn't pre-planned to specifically go somewhere (and it appears that it wasn't), I think this is about the best / least intrusive solution This is my first build and probably my last. But, if I ever build again, it will be with the HVAC contractor working with the architect during the design phase. Why this isn't standard I don't know. The architect designed this house with no regard to HVAC at all! Live and learn. It was tricky from the start to vent the hood and I'm not faulting the HVAC contractor. He did his best but I do wish I had been part of the decision. I'm going to leave it where it is. The windows should be tight enough to keep the smell out when closed and they won't be open often. Thanks again. You have all been very helpful.

Actually there is one brand of electric fireplace that looked so real, it fooled even me and that's hard to do. Unfortunately, right now I'm having a senior moment and can't remember the brand but when I do, I will come back and post. In fact the only reason we didn't go with their electric was because it was a linear fireplace and ours called for a rectangular since we were doing a craftsman style house. At the time they didn't have a linear version, but I believe they do now.