- Joined
- 18 Jan 2010
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OK, sorry, I do get a little heated on the subject, after such a long time of having to defend our corner it wears one down. If I can help then I'll try to answer any questions.
I am biased but I think that is down to my belief in flueless. We make more flued gas fires than flueless and are also one of the main manufacturers of electric fires, so I don't think any bias comes from financial reasons.
You are right Agile about the orange flame, but the fires will have passed CE approval before their sale is allowed. The design of the burner and coal layout is everything in a flueless fire. An orange flame will tend to soot and produce more CO, but of course the customers want an orange flame for the look. A blue flame produces less CO but more NOX, it also does not look appealing. If you ensure there is no flame impingement and a good introduction of secondary air you can have a yellow flame with virtually zero CO, low NOX and a decent flame picture (or as good as you can get with just 2.5kW of gas).
You are not allowed to rely on the cat' to clean the combustion. They are tested with and without the cat' and must pass both. The limit allowed in use is 9ppm in the room (which will equate to around 30+ppm from the appliance), but I do not know any that produce anything like that amount. As I said, we test every fire we make and virtually all will record between zero and 3ppm. As the new fires are burning off paint and oils etc, the combustion actually improves with time.
We do come across diyer's who have fitted their own, but this is true with flued and flueless. We would never condone it and any warranty is instantly invalidated. We put all over the instructions and literature that a qualified installer must be used. If however a diy'er is determined to fit his own gas fire, he is far less likely to harm his family with a flueless. The products of combustion coming out the fire will be clean almost regardless of how stupid he has been, if he tries to fit his own flued fire any mistake with the chimney (downdraught, poor sealing, blocked flue etc) then he has put himself in a very dangerous position. I think I teaching you all to suck eggs here.
Re cut off points, 9ppm is the limit in the room. The ODS on a flueless must cut off before a drop of 1.5% oxygen, a flued fire is 2%. The problem with a cooker is when pans of cold water etc are put on the burners. Not sure what the limit is but I know a man who does if you want me to find out.
I am biased but I think that is down to my belief in flueless. We make more flued gas fires than flueless and are also one of the main manufacturers of electric fires, so I don't think any bias comes from financial reasons.
You are right Agile about the orange flame, but the fires will have passed CE approval before their sale is allowed. The design of the burner and coal layout is everything in a flueless fire. An orange flame will tend to soot and produce more CO, but of course the customers want an orange flame for the look. A blue flame produces less CO but more NOX, it also does not look appealing. If you ensure there is no flame impingement and a good introduction of secondary air you can have a yellow flame with virtually zero CO, low NOX and a decent flame picture (or as good as you can get with just 2.5kW of gas).
You are not allowed to rely on the cat' to clean the combustion. They are tested with and without the cat' and must pass both. The limit allowed in use is 9ppm in the room (which will equate to around 30+ppm from the appliance), but I do not know any that produce anything like that amount. As I said, we test every fire we make and virtually all will record between zero and 3ppm. As the new fires are burning off paint and oils etc, the combustion actually improves with time.
We do come across diyer's who have fitted their own, but this is true with flued and flueless. We would never condone it and any warranty is instantly invalidated. We put all over the instructions and literature that a qualified installer must be used. If however a diy'er is determined to fit his own gas fire, he is far less likely to harm his family with a flueless. The products of combustion coming out the fire will be clean almost regardless of how stupid he has been, if he tries to fit his own flued fire any mistake with the chimney (downdraught, poor sealing, blocked flue etc) then he has put himself in a very dangerous position. I think I teaching you all to suck eggs here.
Re cut off points, 9ppm is the limit in the room. The ODS on a flueless must cut off before a drop of 1.5% oxygen, a flued fire is 2%. The problem with a cooker is when pans of cold water etc are put on the burners. Not sure what the limit is but I know a man who does if you want me to find out.