In article , Dave Plowman (News)
scribeth thus
In article ,
tony sayer wrote:
Some boilers have optional kist to manage the plume

"Easy to fit solution for the problem of plume providing increased
siting flexibility during installation Plume is a vapour trail that is
seen coming from the front, back or sides of a house when the flue gas
temperature drops below dew point. Plume is not harmful but can be
viewed as unsightly and a potential nuisance if it drifts across
neighbours properties or public areas.

Why is it a potential nuisance?..

On a cold damp day they could block the view from a window.

Just how much of a plume do some of these old boilers make?..

Not old boilers. Modern condensing types.


Summat about old steam engines call kettles more often than not)....

tho IIRC they call them "engines a vapour" or similar en France..
--
Tony Sayer