I apologize for the lengh of thi, I'm just trying to explain as much as possible.
Okay, so the house was built in 1929. I'm not sure if this is the ORIGINAL configuration, but it's been this way since at LEAST '94.
I don't know all the terminology here, so you'll have to forgive my ignorance:
We have a chimney with 3 separate holes up to the top; 1 is the fireplace on the 1st floor (not part of the issue here), 1 is the furnace, and 1 is the downstairs (basement) fireplace. The furnace has a stovepipe-type pipe that goes from the top (the outside protuberance at the top of the chimney) down through the actual brick enclosure, and then comes out the side of the brick enclosure in the basement to connect to the pipe coming out of the furnace. Here is a view of the fireplace and furnace; you can see the steps on the other side of the furnace:
Here's a picture of the big chimney column on the furnace side; you can't see the fireplace, but it is on the left chimney wall behind the furnace. The water heater is on the right (you can see it and its pipe behind the stairs):
And continuing past the water heater and then looking back at it, you see this (the chimney wall that continues to the right is the opposite side of the chimney column from the furnace; around the corner and to the left is the fireplace):
So here are my questions, and I hope someone can help me:
1) How can we vent this water heater the right way, with its own compartment or something, such that we don't have to move the water heater? I hypothesized to a chimney sweeper (expertise not so great, it seemed, but of course I know much less) that perhaps we could just connect a long stovepipe-type deal to the water heate'rs vent inside the same shared fireplace chimney, thus sort of faking a separate chimney, even though it's really just a pipe going up the firepace's chimney. He said that the chimney hole for the fireplace was probably too narrow to do that, and it would constrict the opening too much, such that the smoke wouldn't have enough room to go up, and it would probably be coming out the fireplace due to insufficient air flow straight up. Plus, I was worried about the heat on the pipe, and of course sweeping the fireplace chimneny would probably be difficult to impossible. The sweeper said he's seen configurations where the pipe coming out to connect to the furnace vent is a "Y," and the water heater would connect into it, and so the water heater and the furnace would share the pipe. However, you can see from the configuration here that we can't run the water heater vent pipe to where the furnace vent pipe is; it would have to go around the stairs, and would surely not be an upward angle, either. In fact, it would actually have to go downhill, so that's out. Any ideas here?2) If we DO have to move the water heater (a serious pain, because we'd have to completely change the gas lines and the copper pipe of the water intake and output), the water heater is taller than where the current furnace vent goes into the chimney; so how could we arrange that? Are we talking about knoecking a high-up hole in the chimney and re-piping everything, and sealing up the old hole? Is there anything less drastic we could do?
3) I've heard of these "ventless" water heaters that need no venting into the outside, they just sit in the basement and are safe somehow. However, we JUST bought this water heater, and the ventless ones are hugely expensive. I'd like to try and resolve this issue a different way.Sorry about the place being a mess in the pics, and I would REALLY appreciate any advice on this.
Thanks very much for reading, and in advance for any input.