We are under contract to buy a new place that has a ventless fireplace. We are not familiar with them at all and are reading mixed reviews about them. It is not a make or break deal on the place, but we do want to go in with appropriate expectations. The fireplace is actually set in a build out wall that is about 6’x3’ and the fireplace is only operational/viewable on the living room side. The wall goes up to 22’ ceilings so has the potential to be quite dramatic and we are thinking about two things - 1) removing the current inset and putting in a two-sided or three-sided fireplace with glass doors AND 2) tiling or putting stone all the way up to the ceiling so it would become ‘the’ focal point of the place. But we are reading about how the fireplaces can only be run for a couple to three hours at one time and how vital it is to always have working carbon monoxide detectors (which we already do anyway). Our inspector didn’t seem to alarmed about the prospect of having a ventless fireplace, but it sort of took us back, mostly because we are just not familiar with them. Like I said, it won’t be a make or break deal, but we want to know what to expect and how to get the most out of it. It seems sort of sad to have such a dramatic focus if you can’t really use it like we’d like to. We currently have gas logs with a standard chimney flue so this is what we’re used to.
We have a gas fireplace…and we love it. Its not any different than having a ventless gas stove…and all of the gas stoves are ventless. Think about that.
How often do you think you would want to run this thing for more than three hours at a time? Not often, I’ll bet. We use ours on holidays, and even then, we seldom have it running continuously for more than 3 hours.
I think you will love it.
Plus, ventless, you will actually get some heat from it into your rooms…and not mostly up the chimney!
We do get ours checked annually.
ETA…we have the ventless downstairs in our house…and gas logs only (vented) in our family room…so we have experience with both.
Teri, I am surprised that the builder chose to put in a ventless fireplace. My major concern would be the amount of moisture it would put in the air inside the house when it burns properly. Is there a possibility the builder can retrofit it with an outside vent?
Ventless fireplaces are not a good idea. Yes, builders like them because they are easy. Unfortunately, most builders aren’t educated in building science.
“Its not any different than having a ventless gas stove…and all of the gas stoves are ventless. Think about that.”
Not correct. (i) You stove is equipped with an exhaust hood and, most importantly, (ii) the amount of gas used to cook a typical meal is much less than what a fireplace can burn through in 2 hours.
BB, my exhaust hood is not on all the time when I cook.
Honestly, these ventless fireplaces are not meant to be used like a wood burning one…or a vented one. They are for occasional use.
And usually they are put in places where venting to the outside is not possible.
Also, this is a condo…I’m betting changing the venting situation would not be permitted. It didn’t sound like new construction.
“BB, my exhaust hood is not on all the time when I cook.”
See (ii).
CH4 + 2 O2 --> CO2 + 2 H2O
^^ think about that.
Ah, “new” is like “new to Teri,” not new construction. 
I know the chemistry. My house isn’t totally encased in plastic. There is plenty of outside air. We have. co2 detector in three locations. It has never gone off. There has never been moisture or condensation anywhere. Like I said, we get the system checked annually…and that is what everyone should do, in my opinion.
Then again…we use the ventless recreationally…and never longer than a couple of hours. To be honest, it would get too hot in the room if we did.
The new owner needs to understand the limits of a ventless system. If they want to burn for 10 hours at a time, they need something very different.
What you have is a CO detector. I agree that if used infrequently, the fireplace would be ok. I would be concerned if it is used for more than 2 hrs daily (which is what the intended use seems to be). We opted for vented fp for that particular reason.
Agreed. These are not intended for use continuously day after day after day. Yes, we have three CO2 detectors.
But these ventless fireplaces were not designed to use for hours on end like a wood burning fireplace, or vented gas log. That is not their intended use.
Yes, new to us, but the building is actually 135 years old and was gutted for condos about 15 years ago, so occasionally limited in what they could alter. Also on National Register of Historical Places so I’m sure that has something to do with what they were allowed to alter when redeveloping these buildings and what they weren’t. (worse than the ventless fireplace is that we have a second story unit and no elevator! But the historic and unique nature is what drew us to the community). It’s not a make or break deal and I have no intention of judging a builder based on decisions they made 15 years ago on a 135 year-old building… just wanting to know what to expect.
Funny thing is, if I think back over last winter, we probably had a fire in our fireplace a dozen times or less; I’m sure half of those was when D2 was home for the holidays for less than a week. She will be the one who has to adapt to shorter burning times more than H and I.
^^ Thanks… about an hour after I wrote this, H found an article about them in the newspaper he was reading today. I never paid any attention to ventless fireplaces and two days after I learn ours will be one, I know a LOT more!
It really is just for show, right? I agree you won’t use it much anyway. We have a real wood fireplace, I think we light it on xmas day. I can’t be bothered to invest in the cost of the gas insert, I would rather just block it altogether and stop the inefficiency. Burning wood is horrible for indoor air quality and poses significant health risks so like a ventless fireplace, it is more show than blow. Our house has pretty efficient gas central heating.
Wood burning appliances vary by type, quality and installation, so the notion that it’s “horrible” is not universally applicable. Some are safe and proper.
In an attached condo, I don’t think I’d be thrilled about having wood burning fireplaces. At all.
I agree…this will give you the feel of a fireplace on Christmas Eve and the like. It will be nice.
Teri, your H can do some calculations using the actual BTU of the actual fp… If our paper napkin math is correct, a typical fireplace (depending on its BTU) would be equivalent to evaporation of 3-5 pounds of water into the air per hour. In my neck of the woods, where folks freak out about mold, any extra moisture is undesirable. YMMV. We axed the idea of ventless and went with vented. Vented fp lose 20-25% heat compared to ventless, so for folks like us who sometimes have to use them for the whole house heat during windstorms and other power outages, the small tradeoff in efficiency was worth it. CO is easy to deal with by monitoring and proper maintenance. Extra moisture is theinevitable result of natural gas burn and can condense on the windows, ruin the wood, and lead to mold problems. It looks like our approximations were close:
http://www.ehow.com/info_12140163_amount-water-natural-gas-propane-ventless-heaters.html
Another thing to consider. Does the house have other gas appliances and therefor by code did it require a whole house vent? Ours is all gas (appliances where heating is involved except the ovens and D/W), and by codes it was required to have a whole house ventilation in place (it is run on a timer built into the furnace and is wired into the fan in the downstairs laundry room).
Anyway… Congrats!!! It sounds like an awesome place. One more piece of advice from these folks who have a 2-story high ceilings in the living room: a fan is really nice to have. Hot air rises to the top… It is a good idea to whirl it around. 
I think we have to accept that you and I live in very, very different climates. Remember, around here, we ADD humidifiers to our furnace to ADD moisture to the very dry, cold, heated winter air, which can cause damage to wood as well, if it’s too dry. I know, I know… not a problem you have in your neck of the woods. 
There is a ceiling fan already, so I’m sure that will be running continuously, not only to move the hot air back down where we are, but there is also a loft and we are told it gets warm in non-winter months, so we will likely need it to move air up there, too. You did give me food for thought, though… another question I’m going to ask - how often do people in this community lose power? Where we used to live before this house, we lost it several times a year because power lines were all above ground. In our current house, we rarely lose power as power lines are buried. Thankfully outside walls in new place are about 2’ thick, so well-insulated if we do lose power either during the summer when air is on, or winter when heat is on. Of course this is all speculation… we won’t know until we get in and live there for a while. Our inspector did tell us that these fireplaces provide excellent heat when they are on, but we’ll just have to remember not to have it on for too long… is what I’m learning.
Oh, and yes, all other appliances (stove/oven, hot water heater, furnace) are gas.
Thanks for the article link - good to know this stuff. We don’t remember the BTUs of the fireplace from Friday, and don’t know that we’ll be back in the unit again before closing. And there’s still a possibility we may replace the fireplace insert with a two-sided glass door insert so the fireplace can be enjoyed from both the dining room/kitchen and living room. So even if we knew the BTUs now, that may change if we swap it out for another insert!
Good to know the humidity is not going to be an issue (I had no idea if it would or not since I am not familiar with your local climate), but it might be for some folks who are considering this type of a fp and come here to read your thread. Somehow, only CO comes up on the radar, and very rarely folks would consider the impact of other combustion products.
It certainly sounds like a nice place. Fingers crossed!