Probably going to pick one up after xmas when Lowe's pulls the 50% off.   Basement is unfinished so should be easy to hook up.  Want to place it upstairs (2bd/1ba/800sqft) in the living area which is open with the kitchen and dining room.  Just looking for a way to keep the main heat off and kick something on as soon as I get home for some heating in the area I'll be in most of the night.... I keep a 1K watt space heater on in my room most of the night and that keeps it about 65*.   No real need to have heat in the rest of the house or basement.  

Only bad I have heard about them is they create a lot of moisture.  Right now in the house I'm having nosebleeds and sinus problems due to the lack of moisture, even with a humidifier running at about 3 gallons of water a day.  

I think my total cost should be around $300 installed for a decent unit.  Don't care about the looks.  Floor mounted antique look or the wall mounted one will work for me.  Hoping to recoup my expenses in a year or two.

RUN!!

Sales guys will tell you that they produce no toxins, etc from the combustion but I just don't believe it.  Every one I've ever installed for a customer gets the same complaints.  Supposedly the levels  of CO are nearly unmeasurable and the only substantial by products are CO2 and water vapor.  Based on personal experience I'd say no to installing one.

While NG that is burning correctly [blue flame] produces little to no CO, high humidity can change the flames to yellow [CO]. Water vapor [high humidity levels] contributes to CO production..........see where I am going with this? Also, aldyhydes are produced which many people can smell, others, not so much. Used for a short time [as intended] they work OK, used how many people use them, you can see problems. In a well sealed house, you can deplete the oxygen levels, increase the carbon dioxide levels, and eventually, begin to produce CO.

I'm talking just turning the thing on and off until I hit 60*, then use the electric for the rest.  House is made in the late 50's.  Single story ranch.  Newer windows, but that's it.

I have This One and love it.  It has  a ODS(oxygen depletion sensor) and will turn itself off.  I also have a seperate CO detector just in case.  99.9% efficent.   I only use it during the day as supplement heat.

I put one in my old house. When I turned it on for too long it would give me a splitting headache unless I opened a window.   Kinda defeating the purpose.

I only used it on low from then on out. Mine had an O2 depletion sensor on it too, and would shut itself off if the O2 got too low. Unfortunately I think I needed more O2 than the fireplace did.

Based on my direct personal experience I would not buy one again.

I would not trust a vent-free model.

Kharn

Not a fan of using my house as a chimney.  Even though NG burns clean I would pass.

Considering that everyone who owns and used a gas range is doing the same thing, you'd see more of an issue if it was truly dangerous. Issues arise because people don't use them the way the are supposed to. Heck, some use them to actually heat the house and that is not what they are for.

Not sure I trust them either..   If the house is well insulated, there is only so much oxygen in the house..       I high traffic area where the door gets opened often is one thing,  but not sure I would let one on constantly in a house.    The stove is running for a couple house max.  usually an hour or so.