ventilation for gas fires

[adam2411]

Hey all just wanted to get your thoughts,ive always been under the impression that a fire under 7kw doesn't need ventilation,after talking to a colleague who needed some advise on a fire another colleague over heard and said that all fuel effect fires need 100cm2.

In my viper book there is a table that states that any dfe fire needs 100cm2 now I know that the majority of basket fires and the wall mounted dfe fires with the cat inside unless it states otherwise in the MI will need one,but he was saying even the inset fires with the coals and with the glass still need 100cm2.


Any thoughts?

 

[ShaunCorbs]

what do the mi's state

 

[hammers4spanner]

Read what the MI's state as above

 

[lame plumber]

if no mi's assume the worst and go for vent.

 

[REDSAW]

yeh, thats the call.
no m.i's then a 100cm vent required unless prooved otherwise.
all cats need one?

 

[finkbat]

Depends on the type of gas fire. I think there is some confusion here between a DFE (basket), ILFE (Inset Live Fuel Effect), and flueless (with cat). DFE generally yes (100cm), ILFE generally no, flueless yes. Does depend on other factors and MI's. Consult GSR engineer if doubt.

 

[spanner]

what do the mi's state

No MIs 100cm2

 

[ShaunCorbs]

No MIs 100cm2

Most of the time you can get mis just look on internet if no mis go off viper book

 

[finkbat]

No MIs 100cm2

Depends on the type of fire. Inset fuel effect fires (ie full metal body that sits inside the builders opening, with a spigot that protrudes into the flue) do not need any...

Generally the only ones that do are DFE (Basket in the bottom of the builders opening) or flueless.

 

[spanner]

Yes cassette type ILFE.

 

[finkbat]

Generally don't need any then. DFE's require it as they've normally got to be fitted on a 175mm flue, so have a lot more air going through the chimney. What I think you're taking about would only need 175mm, less air so less ventilation needed.

 

[Simon F]

"fuel effect"
a bit open ended, what about pebbles??

as said its the manufacturers instructions that are key,
but fire type is also important.

let the collegue who said it needs a vent automatically tell you what hes quoting.

 

[GrahamM]

Spot on finkbat!
Having worked on dozens of different ILFE fires with MI's available I don't recall any that has ever stated ventilation required.(subject to satisfactory spillage test etc though.)
That is why most ILFE's are bellow the 7kw cutoff.
This is also clearly documented in British Standards.
But as mentioned we really require the MI's to be 100% clear on this.

DFE fires are a different story. Unless your MI's say otherwise you are going need at least 100cm² vent.

 

[Jehannum]

It's worth remembering that current standards state the 7 kW allowance for non-DFE open flues shouldn't be taken for granted. Newer houses and older houses that have been draughtproofed, double glazed or insulated are more airtight than properties built when adventitious air was first formulated. The onus is on the gas engineer to determine whether adventitious air is there or not.

 

[spanner]

And do you have to take into account the space the ILFE Or a DFE sited in must be within 35cm2 minimum

 

[firemant]

The bottom line is that your mate is wrong.