Another thread mentioned gas tumble dyiers.

I am interested in one but would like to know the gas side of things.

I see that it must be vented to remove the combustion products and
that is fair enough.

As to the gas side, I suppose that a 15mm supply would be ok, but if
the suitable source of supply is not adjacent then having it fitted
could add a fairly hefty 50% to the cost of the appliance??

Also am I likely to find an appropriate fitter for a tumble drier??

Cheers for any comments.