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Gas Stoves - Vent Free vs Direct Vent

I want to install a gas (LP) stove in our newly remodeled dining room, which is approx 350 sq ft. The room has three openings into other areas...each opeing with a door...so the room can be closed off completely but ideally I would like some heat to transfer to other areas. It's a two-story farmhouse built in the 1840s. The stove will be used to supplement the current heating system and used only on weekends so will get limited use. And winters can get cold.

The quandry is I cannot decide if I should get a Vent Free or a Rear Direct Vent unit. I'm leaning towards the vent free but have some reservations. Does anyone have a vent free who can offer some practical advice? I keep feeling the sales people at the various stores I've been to aren't being completely up front so I'm hoping you smart folks who vist this website can help me!

Oh, and any advice on brands and BTU/heat output is welcomed as well.


Re: Gas Stoves - Vent Free vs Direct Vent

Avoid the vent-free unit would be my advice. Vent-free is just that.....vent free. That means all the combustion by-products are being dumped into the air you're breathing. Vent-frees are illegal in many jurisdications for just this reason.

Also, consider that LP contains copius amounts of water vapor. All that water-vapor will also be dumped inside the living space. Not a good thing, to say the least.

Re: Gas Stoves - Vent Free vs Direct Vent

I have a vent free LP gas log fireplace that we have been using for years with no problems. Ours is an old house built in 1870. We have insulated and sealed it up as best we can but like most old houses it still leaks.

Caution 1-never use a vent free in a closed room, oxygen deplition is the problem even if it has an oxygen deplition sensor.

Caution 2-is your house is really sealed up it will give off a lot of moisture, usually not a problem during the dry heat winter unless it's run all the time.

Caution 3-Proper maintenance is a must with a vent free fireplace although not a big chore.

Get one that will work without a blower, that way you have heat if the electric is off, but one that has a thermostatic control.

IMHO in your particular case it sounds like a vent free would be fine just don't close the doors.


Re: Gas Stoves - Vent Free vs Direct Vent

I have to agree with goldhiller on this one.

There have been more accidental deaths from carbon monoxide poisoning because of these ventless heaters than you can imagine; any burned fuel from a heater, as goldhiller points out, spews deadly gases into the room & depletes the air of oxygen.

Why take the chance when a 4" double-walled stainless steel side vent or thru the roof vent can be easily installed, even as a diy project.

If I can't convince you to go with a vent system, at least buy a carbon monoxide alarm & keep it in the room while the heater is on.

The problem is particularly dangerous if a couch is in the room; oxygen depeletion makes the occupant drowsy, he then takes a "short nap" & never wakes up.

There is also a much higher risk of fire with these heaters; since they are not firmly attached by a vent to the wall, they are frequently accidently tipped over.

Heating capacity is calculated in BTU's/hour.

Assming 8' ceilings, a back of the hand calculation takes the square footage of the room & multiplies by 30; thus, a 20' X 17.5' room = 350 X 30 = 10,500 btu/hr needed to heat this roo(this is for a room with tight-fitting windows & exterior wall insulation; do the HLC below to be sure).

The heater would have its btu rating printed on its housing.

A more exact heat loss calculation can be obtained by using one of the sites below.

You also didn't mention the type of central heating system you have or your general geographical location; if you have hot water or forced air heating, we can help you plan an extension or a zone setup to heat just the dining room, which will cost lots less to heat than buying a space heater.


Re: Gas Stoves - Vent Free vs Direct Vent

Here in this region these are not allowed by code ... plain and simple ... I agree with goldhiller and JacktheShack having combustion without venting is tricky and dangerous.

Re: Gas Stoves - Vent Free vs Direct Vent

My situation was my father-in-law had a rent house that he passed on to me to spend a lot of time on to continue to rent or not to rent. I chose SHOP! But the heater was the type that looks like a big old TV console and it was old and ran a lot and vented most of the heat straight out the ceiling. I installed a free standing ventless propane heater that cost about $250. The house is not insulated well at all so has an exchange of air and is about 950 s.f. with 8 ft. ceilings and three separate rooms. The heater keeps it plenty warm, carbon monoxide isn't a problem and the propane use has gone way down. It just fits my situation but wouldn't others that are better insulated. The humidity is just about right for our schizophrenic winters here in Arkansas too. I hope your water is good and muddy now.

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