Planning an update for next year

Bought this house new 12 yrs ago with a builder installed Majestic UVC36, NG Non-vented fireplace. The heater works great but there has always been an annoying smell when lit. It sort of smells "sour" and we have been putting up with it since new. Filters cleaned every year per the mfg instructions, logs carefully placed as instructed etc. Last year, I even called the local gas company to come and check it out, his inspection revealed nothing wrong, took sniffer/meter readings, all were well within specks. We have a Co-2 monitor installed, never has alarmed, but I have always had to remove a normal smoke detector in that room to keep the whole house from alarming. After 11 years, changed all the smoke detectors to an "improved version", and within a minute, the SD will alarm. So...I think I would like to change this insert out to a vented version, this summer, hopefully some will be on sale???. The vent is the biggest question to muddle through. On top of this heater is a cove that is the same width as the stove and about 2 feet high, 2 feet deep. Hate to have to run a vent up through the middle of this (to the roof, approx 15') as the wife is giving me the "eye" about it, can run to an outside wall, on a porch and either leave it there??or elbow it up through a 4 ft wide soffit to the roof. In either case, what type vent would I use, double inner/outer (one for input air and one for exhaust)??. Just in the planning stages right now, appreciate any thoughts.

Direct vent (inner/outer tube) can run through the wall, either straight out the back of the stove so no pipe is visible or up out the top and then through the wall (or ceiling)... it depends on the model.

If you vent through the wall there are required clearances from the vent to soffit, windows, etc. This document gives the required clearances for Simpson Duravent pipe.

Tx Fan Man. Finally got thru the document and understand most of it. One option is to come up with the vent and make an immediate 90 degree turn to go thru an outside wall. This wall is on a covered porch where the soffit is 48". Think this might then vent up into the attic and exit thru roof vents. Does that sound like workable idea? or would it be best to do a 90 and take it up thru the soffit and then the roof. Forgot to add, behind the FP is a bathroom.

Top vented stoves may have a minimum amount of vertical pipe before the first elbow. Mine needs at least 24", and that's what I used as any move would put the vent on the outside too close to the soffit. If I understand correctly you want to go through the exterior wall, then back in through the soffit and out the roof? Seems a lot of work.

Thats the question, it seems like I do not have any really good choices that are straight forward. In ref to the picture, you can see that the other option is to go thru the center of the opening above the FP, wife is not supporting that idea :-(

Daksy: I called a local gas/fireplace guy this morning, awaiting his thoughts, but yes will have to choose a compatible FP to allow the vent install that is up to code and is pleasing to the eye.

Question #2. I assuming a couple of things here, vented vrs non vented should not allow any odor etc in the main room? (the main reason I am changing) IF I get a blower for the FP that does not change?? The blower uses air from heat exchanger or sealed shell around the main FP. Sorry lost here.

This may see silly ?? since I am in Central Florida, but there are times that we unfortunately go below freezing here. The present fireplace was able to keep up with the temp without any help from the heat pump, otherwise would not be looking to change. ;-) Something I called "Palmsicle"

Thanks...Great reply. Will post back when the local guy has a look.

The fireplace/Gas guy was here this morning. After some measurements, said that by the time you add a vertical stack to the fireplace then go horizontal thru the wall you would have less than 36" (code) to the soffit. Also could not just exit on the porch because it is considered a closed space living area. It is screened but his past experience was that eventually people want to enclose the screen/porch and therefore (code) will not allow it. Only solution is to go straight up thru the top/attic/roof with about an 18" exposed stack on the roof. Also did not realize that the firebox is larger than the exposed front area and therefore, all the tile will have to be removed, restructure with new tile, and structure around the 6" stack. (approximately a 10" square area) etc. One more note is that an electrical outlet will have to be installed to run the ignition & blower. How do you spell "money pit"?. He is looking at compatible units and will be back in contact.