"sf" > wrote in message
...

> >
> > I can do all the required sums and most manufacturers specify the
volume
> > extracted, the thing that I am having trouble with is the basis for
> > calculation of the desired rate of extraction.
> >
>
> Basis? Is this one big room? If so, calculate that.

We don't seem to be on the same wavelength here. I can calculate the volume
of the the room, I know what the heating capacity of my cooktop and oven
are. The question is what is the basis of computation of the required
extraction rate to service that room?


> > >
> > This site is interesting, they give a rule of thumb for bathrooms of 8
air
> > changes per hour but I cannot find anything on kitchens.
> >
> You can't extrapolate?

No I cannot. I don't have a 50 Mj gas stove in the bathroom. I don't fry
and produces any smoke in the bathroom. Please explain how to extrapolate
from bathrooms to kitchens.

David