As garyg points out, one of the combustion products is water vapor and that may play havoc with a tightly sealed (read that as properly built) home nowadays. By going ventless, you could be setting yourself up for mold and mildew issues down the road. IMO, I wouldn't even consider ventless.

We had a ventless log set for 7 years and never had any issues with water vapor, mold, or carbon monoxide. I highly recommend ventless over direct vents (which I currently have in our new home) as their efficiency is far superior. IMHO, the water vapor/mold issue is way overblown and unsupported by any evidence. Plus, you don't hear folks steering you away from whole house humidifiers do you?

We've had one for 10 years now. It has a built in CO2 monitor. If it detects CO2, it shuts the fireplace down. I've also installed an independent CO2 monitor that measures CO2, not just beeps if it is present. We have never had an issue with it. I will agree that you will get some added moisture, but it seems like many homes that I am in are running humidifiers during the winter heating season. Obviously this fire place will not be a primary heat source and if like us you use it for atmosphere, then it will be fine. They do put out a lot of heat. Keep in mind that this isn't going to be a back-up heat source in case your power goes out. They require elecricity to run a blower/fan.

Wow...there is "superchick" and now "superiorgirl2". What's a humble male to do in the presence of super and superior girls?

Garyg-HA! My id name has nothing to do with superiority, I assure you!!! So you can rest easy! :)

I suppose I should have prefaced this question by saying that we live in the very DRY plains and I can't imagine that humidity in the house would be a problem. We literally have 20% or less most days of the year. Right now we have a whole house humidifier and it stays on all year. So surely running a ventless possibly a couple hours a day during the winter wouldn't be an issue.???

I do appreciate the posts from people who have them and like them. I have to say, I REALLY don't want one, but it's either that, or nothing and by golly, I WANT A FIREPLACE!!!!!!!!!! :)

This is a tough decision if you have no other option.
I have to say that I had a very negative experience with 2 new ventless propane inserts
. . The soot generated, permanently stained all the edges of our new light fitted carpets and there was a black film over everything. These things are illegal in many places and now I know why. We installed 3 new vented units and the difference is day and night.

Hold the phone. There is now "usgirl" along with "superchick" and "superiorgirl2"? This is the Fireplaces Forum? I am impressed. You gals rock.

When going ventless do this: Install just a ventless firebox(no factory installed logs) have the gas line pulled into the box, then install a set of logs in it. You'll be fine with it, and I bet you'll love it. Try to keep the run time to 4 hours or less per day, and ask about fresh air returns. Normally direct vent installations are consider code compliant when installed according to the manufacturers directions. These directions give the longest vent run allowed. So you may have some options if DV is what you really want, I'd call the inspector myself and ask about it. Some models run well into the "40' long run" area.

As a gas fireplace repair specialist, I choose not to work on unvented equipment. The margin of safety is sharply reduced with unvented equipment.

IF every person read, understood and followed all the warnings and recommendations packed with unvented equipment, I would expect they would operate safely. But I've never encountered anyone who did that.

Just as an example of the misunderstanding people have, take Superior Girl's post above. She reports that her unvented fireplace has a CO2 monitor built into it. Well, it doesn't. I suppose she is talking about a built in CO (carbon monoxide) monitor, but it doesn't have that either. Unvented equipment has an oxygen depletion sensor which shuts off the equipment if the oxygen in the room gets too low.

But that doesn't detect carbon monoxide caused by dirty burners or logs that aren't arranged according to the manufactuer's specifications.

If you can't install vented equipment in the place you prefer, find another place. Unvented equipment may operate OK, or may cause you problems or kill or injure people. It's not worth the risk in my opinion.

Most direct vent can early vent 20 plus feet, I sell these items every day.

I wanted to go ventless and my budy who is a HVAC contractor and city inspector said no way. He did not feel they were safe enough. They are even banned in Canada? I think thats what I heard. I took his advise and got a direct vent instead.

DISCLAIMER: I am not an employee, seller, or representative of any trade organization, manufacturer or retailer of gas heating appliances. I *am* a concerned consumer who is feverishly trying to educate himself about the pros/cons of direct-vent and vent-free gas fireplaces and their wood-burning counterparts.

That said, I am continually amazed and disturbed by the amount of misinformation/disinformation that is disseminated in so many places on the Net as "advice" and "expert opinion." It's frightening how much of it is little more than hearsay or anecdotal in nature. I don't by any means claim to have all the answers, but in my efforts to educate myself, I've at least managed to come across details of some formal studies that have been done about a number of concerns that people may have regarding vent-free gas appliances. If nothing else, it's interesting reading and provides something more than the "my opinion," "I heard,", or "so-and-so says" type of often-misleading advice that emanates from forums like this.

For one pretty thorough treatment of the subject, check out http://www.ventfree.org/images/stories/files/vf_guide.pdf. Admittedly, it is published by a potentially biased trade organization, but it at least presents the issues in a relatively objective way. If anyone has sources of equally-rational contrary information, I would love to hear of it...

If all you really want is ambience, go electric. It's safer, and you don't have to worry about all the hazards with ventless gas.

Another option would be a ventless gel fireplace which burns alcohol gel, basically a variation of Sterno. These have come a long way and burn very clean. Fuel can be a bit costly but you get real flame ambiance without the CO risks or venting/moisture issues. Many of them come with fairly attractive mantel units to fit a variety of designs.

I would skip the ventless gas fireplace.