Gas Ventless Fireplace

camiarrobino

Hello -

Wondering if anyone has any thoughts / experiences with natural gas ventless fireplaces? I'm intrigued by the idea for when I finish some of my basement. Almost seems too good to be true - to not have to vent at all despite a fossil fuel being burned? I'm in MA if local laws matter.

Are they an accident waiting to happen, anyone have any experiences good or bad with them, etc?

jesmed1

It is too good to be true. Whatever comes out of the exhaust is going directly into your home. There's no way I would get one of those. Also, one of the main products of combustion is water vapor. All that water vapor ends up inside your house, and goes looking for a cold place to condense into liquid, inside cold walls, etc. Then you have a mold farm waiting to grow.

Spend a little extra and get a direct vent. Direct vent means you can pipe directly through the sidewall. Since you're in the basement, you can't go horizontal right away; the vent would have to go vertical up through the ceiling into the first floor and then go out the sidewall.

camiarrobino

Well, the condensation / water issue is nothing. It could be drained into a nearby condensation pump (which pumps into the slop / laundry sink). I have 2 of them, 1 for the tankless WH, and the other for the central air / dehumidifier.

unfortunately I think that venting may make it just not worth it to me. I'll get numbers for sure when I'm ready, but if it's going to add significantly to the price, I'll just go with a mini-split in the basement for primary HVAC and maybe an electric fireplace to use sparingly just for ambiance, if I really wanted

FWIW, in the back of my house, a significant portion of the basement is above-grade (walkout with a full size door to the backyard and all). Not sure if that would help the venting situation at all

pecmsg

They should be outlawed. 

realliveplumber

The condensation water issue is something. It is a byproduct of combustion, and is not "drained" and collected. Its in the air.

ChrisJ

@Tim McElwain

jesmed1

If you have a walkout basement, you have a perfect setup to vent directly out the back wall. It takes like 2 feet of horizontal pipe, a hole in your wall, and a termination cap. It's not that hard.

But if you don't want a direct vent, then I suggest you forget the whole idea and just get an electric fireplace for ambiance.

Bob Harper

There is not a single building scientist in the US who endorses lung vented fireplaces. They stink, dump a gallon of water every 3 hrs into the home, require maintenance, stink, often are grossly oversized for the space, installed in mismatched climatic zones/ poor construction, they stink, and they generate noxious compounds such as aldehydes and NOx. Did I mention they stink?
Go direct vent or electric.
MASS requires you to choose products approved by the Plumbing Board and lots of documentation. Good luck.

ChrisJ

Bob Harper said:

There is not a single building scientist in the US who endorses lung vented fireplaces. They stink, dump a gallon of water every 3 hrs into the home, require maintenance, stink, often are grossly oversized for the space, installed in mismatched climatic zones/ poor construction, they stink, and they generate noxious compounds such as aldehydes and NOx. Did I mention they stink?
Go direct vent or electric.
MASS requires you to choose products approved by the Plumbing Board and lots of documentation. Good luck.

But do they stink?

EdTheHeaterMan

camiarrobino said:

Well, the condensation / water issue is nothing. It could be drained into a nearby condensation pump (which pumps into the slop / laundry sink). I have 2 of them, 1 for the tankless WH, and the other for the central air / dehumidifier.

You missed the point. This condensation is not forming at an appliance. It's not in a pan at the bottom of the fireplace appliance. It is water vapor in the air of your home that will increase the relative humidity of the air in that room, well over the capacity of your household dehumidifier. This is the humidity that may look for a cold can of beer or glass of ice water on the table next to your easy chair. That is why the Mrs. tells you to use a coaster on the good furniture. The cold window that may drip onto the ledge that will rot out the window frame, the space in the wall where the outlet cover may allow water vapor to condense on the junction box and stay damp behind the wall, How many condensate pumps are you going to use and how are you going to collect all that condensation from all those places.

So that's why I believe you missed that point.

As far as non vented appliances are concerned, there is a minimum size room needed for that appliance and there must be a minimum amount of infiltration in the home to support combustion. They are smaller output appliances. You will not get that large blazing flame that you might expect from a Fireplace that has a chimney. If you read and follow the instructions (which many people don't) Yor are required to open a window to insure adequate combustion air. If you are finishing off your basement to become a recreation room, chances are you will be sealing up the natural draft infiltration places that will provide combustion air for your heating and hot water appliances. Make sure you don’t choke the air needed for those fires in your home.

Yes there are fires in your home when you have gas heat. And those fires need air to burn properly. Cover up all the holes in the house and you cover up the air need for the heat and hot water.

So, knowing all that, there are some non vented heating appliance that are safe when used properly. The problem is that most folks can not be trusted to follow the directions and therefor Fire officials and heating professionals are pretty much in agreement that non vented gas appliances are not the best idea. But it is your home, so do the research and consider who might be using that appliance in the future. Teenagers are known to be smarter than their parents for at least 6 out of those 7 years.