flueless gas fire

The flame is yellow because of glowing carbon particles. This is an indication that carbon monoxide may be being made. It happens by a "reduction" process. CO2 (carbon dioxide) passes through the hot carbon particles and is reduced to CO. Sometimes it gets burnt back to CO2 later in the process but it may be escaping into the room. Do not use until it has been serviced.

The gas fires with a coal/wood yellow flame effect have massive amounts of extra air introduced "above" the flame to ensure CO is converted to CO2. Hence they are very inefficient.

You don't say which you have got. Definitely get a CO alarm. All gas fires are very inefficient by todays standards.

I installed one of these in our previous house in the 1960s. I have a feeling they are now illegal.

Mostly bollocks (with regard to flueless appliances).

Have a look at

Tim

Wrong.

Tim

In article , Stephen writes

You haven't given any indication of the age of the appliance, is it some relic from the 1960s or something more modern?

How about a picture, shared via

Any manufacturer's markings on the body?

Look on the appliance (perhaps behind a control panel) for the appliance's spec plate (there will be one). Read the 'GC' number from there and search using that "GC number " (without quotes) for the maker and model. Download user and installation instructions and go from there.

Actually it is near enough 100% efficient, provided it isn't producing significant CO or soot (which you will soon notice).

CO monitor would be a good idea.

Even if it's not producing CO, it will put a lot of water vapour into the atmosphere in the house, possibly leading to condensation, streaming windows and mould problems.

That was my thought as well, and burning natural gas produces more water than other fuels.

I had one of these and the condensation it caused was terrible. It even made fabrics feel clammy. The only way we could use it was with the windows open.

Bill

What about those gas heaters that are portable with a tank of camping gaz or whatever inside. the main issue I thought with those was lots of water vapour. Brian

So what is the process for forming water then. it obviously cannot be that efficient if a good deal of the energy goes to make H2O after all. I was thinking of getting a gas bottle heater in case of power cuts as I'm all electric here. Brian

So if you have one of these and put a de humidifier on it, do you get free water? Brian

Gas burns in air to give carbon dioxide and water and heat. Natural gas is mostly methane, CH4. If the carbon in the gas wasn't combusted to carbon dioxide, or the hydrogen in the gas wasn't combusted to water, less heat would be evolved. Energy is not used in making the water, it is produced by making it.

CH4 + 2O2 -> CO2 + 2H2O + heat

And as the water is produced as a gas, extra heat can be recovered by cooling it to the liquid phase, as is done by condensing boilers.

Of course, as long as your electricity and gas are both free. ;-)

Tim

and it happens with a flueless heater when the water condenses out on the windows ;-)

Indeed. I had a small one providing background heating to a stairwell / hallway in a draughty Victorian house before I could afford central heating. I would not recommend them, but if you are on a tight budget they are (theoretically) efficient.

replying to Brian Gaff, Dave wrote: I know its an old post, but saw this as I was browsing. Complete combustion of a molecule of CH4 (gas) + 2 O2 (Amount of oxygen needed in air) = CO2 (Carbon Dioxide) + 2 H20 (water). Incomplete combustion is a reduction of oxygen on the first side of equation, which then has less to transfer to the other side, producing CO (carbon monoxide), instead of CO2.

If you used a proper news reader like Thunderbird, then you wouldn't see 4-year old posts that are no longer relevent.