I'd like to install a gas fireplace insert and ventless seems like a good choice and would be the easiest DYI project but most fireplace stores seem to really push vented over ventless. I can see a financial incentive for companies pushing the more expensive vented inserts and I want the best system possible for my budget. I can probably easily install the insert and tie it to my gas line but I'm not comfortable cutting holes in the side of my house or roof for a vented gas fireplace insert. So what are the pros and cons for a ventless gas insert compared to vented?

Pro: easier to install.

Con: emits dangerous and unhealthy gasses into your family's living space. The worst of both, uses O2 from your house and replaces with noxious gasses.

I'd never put anything that burns NG or propane as an unvented device in my home. OP, if you aren't comfortable or have the know-how or tools to cut a hole in your exterior wall, hire someone who does.

If you're gonna have one, I vote wood-burning Fireplace Insert.

Quadra-Fire --> https://www.quadrafire.com/bro...inserts/wood-inserts

quote:

Originally posted by PASig:
I'd never put anything that burns NG or propane as an unvented device in my home. OP, if you aren't comfortable or have the know-how or tools to cut a hole in your exterior wall, hire someone who does.

This.

quote:

Originally posted by nhracecraft:
If you're gonna have one, I vote wood-burning Fireplace Insert.

Quadra-Fire --> https://www.quadrafire.com/bro...inserts/wood-inserts

Thanks for the suggestion but wood or electric aren't a consideration at this time.

Vented, no question. As said, you don't want the combustion products in your air.
I've had a vented gas fireplace for almost 30 years; the vent pipe isn't that big.

quote:

Originally posted by PASig:
I'd never put anything that burns NG or propane as an unvented device in my home. OP, if you aren't comfortable or have the know-how or tools to cut a hole in your exterior wall, hire someone who does.

If I go with vented I'd definitely hire someone to vent the unit

Long story short - I have zero desire to have a ventless gas fireplace. I'm in oil & gas so I have read way too many asphyxiation incident reports and don't want to become one.

Long story long - I had a vented gas fireplace in Alaska. We had a particularly nasty cold snap and I flipped on the gas fireplace one Saturday morning to take the chill off the living room. Then, I went upstairs to do something for several minutes. As I was coming back downstairs, I notice the cats were walking unsteady, and when I get to the bottom of the stairs there was a distinct lack of oxygen. There was a 1/2 bath next to the room with the fireplace so I ran over to it and flipped on the exhaust fan. Then, ran over to the sliding glass door and opened it to provide fresh air. Then, shut turned off the fireplace.

Unbeknownst to me the gas fireplaces vent froze shut turning it into a ventless fireplace.

Afterwards, I bought a plug-in CO detector with a digital display to put in the room with the fireplace. I've kept this practice in my place in Can-eh-duh and now here in Texas.

So it looks like the consensus is to go with a vented insert.

My relatives have a ventless. Being in FL, I can tell you that it NEVER gets used, because it throws sooooo much heat into the living area. Way too much heat.

We have a vented in our new home. The one time I have turned it on, it was nice and pleasant but I did not feel like we were cooking.

And they add to moisture inside the house FWIW.

quote:

Originally posted by tatortodd:
Long story short - I have zero desire to have a ventless gas fireplace. I'm in oil & gas so I have read way too many asphyxiation incident reports and don't want to become one.

Long story long - I had a vented gas fireplace in Alaska. We had a particularly nasty cold snap and I flipped on the gas fireplace one Saturday morning to take the chill off the living room. Then, I went upstairs to do something for several minutes. As I was coming back downstairs, I notice the cats were walking unsteady, and when I get to the bottom of the stairs there was a distinct lack of oxygen. There was a 1/2 bath next to the room with the fireplace so I ran over to it and flipped on the exhaust fan. Then, ran over to the sliding glass door and opened it to provide fresh air. Then, shut turned off the fireplace.

Unbeknownst to me the gas fireplaces vent froze shut turning it into a ventless fireplace.

Afterwards, I bought a plug-in CO detector with a digital display to put in the room with the fireplace. I've kept this practice in my place in Can-eh-duh and now here in Texas.

Good Lord. Smart.

This is one of the few things I actually know something about and so here goes:

"no one has ever been harmed or killed by a properly installed, operated and maintained ventless appliance:

This is a true statement... if you actually read the operating instructions you are supposed to open a window or door before operating the ventless appliance.... It actually goes down hill from there.

To cut to the chase... if you are looking at a gas fireplace the way to go is a high quality Direct Vent Unit. One that is what I call a listed heat producing unit.... it will show how much heat comes out for how much gas you burn.

If you must have one, vented.

Vented all the way…

I once rented an apartment with a ventless gas fireplace. Completely useless. Every time it turned on I got a headache and the place filled with fumes. As everyone has said above vented is the only safe way to do it.

We’ve had two places with ventless and never used either. We’re not really a gas fireplace kind of family to begin with, but in both houses the ventless would quickly set off the smoke detectors. As a result we never turned them on. Really sucked during snowpocalypse 2021 as I didn’t dare turn the fireplace on when the power was out.

Our current place is vented and as a result we’ve actually used it a few times.

Sounds like several of ya'll have had old/malfunctioning/poor quality ventless fireplaces...

Both my prior house and my current house came with ventless natural gas fireplaces. I didn't use them daily for long stretches, but I've used both on semi-regular occasions over the past 15 years, with no ill effects. Neither one ever caused headaches. And my carbon monoxide detectors in either house never went off.

They aren't intended to be a primary heat source that's run constantly, but act as supplemental heat when desired, like a space heater. I mainly use mine for an hour or so first thing in the morning to take the chill off with my morning coffee, or on and off throughout really bitterly cold days. Plus it's nice to have a gas heater like that as backup for our semi-frequent power outages from stuff like ice storms.

Yes, ventless fireplaces produce small amounts of carbon monoxide, but they are (necessarily) designed to combust more efficiently than vented units, so a properly functioning ventless unit shouldn't be pumping out large enough quantities of CO to be dangerous if used with even a little moderation. It's not the same as running a vented fireplace with a blocked vent.

And yes, they emit water vapor as a byproduct of their combustion, but considering that winter air is exceedingly dry anyway, you're not likely to run into issues with excessive humidity/moisture under normal circumstances. (Again, if the unit is working properly, and you're not running them 24/7.)


Were I installing a gas fireplace from the get-go, like with a new construction custom home, I'd probably go with vented. But I'm not going to tear out my properly functioning ventless unit to replace it with a vented unit.

However, those of ya'll whose ventless units cause headaches and set off smoke/CO detectors definitely need to get them repaired/replaced/removed ASAP! You'd do the same if you had a gas stove that caused headaches and set off smoke/CO detectors every time you turned on a burner, right...?

I have a small free-standing ventless fireplace in our home. We use it almost daily in the winter to supplement the furnace. Biggest drawback for us would be condensation on windows if it’s super cold outside.