On Mon, 17 Sep 2018 23:21:58 +0200, Brian Reay wrote:

On 17/09/2018 23:12, Peter Parry wrote:
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


There are different types, at least 3, of detectors which are
recommended for different rooms/areas for just the reasons you say.
Placing the right one in the right location/checking it has been done is
the kind of thing I'd expect a competent Building Inspector to be able
to do. May be a call to the local council?

I went for a compromise:
https://www.toolstation.com/shop/p52932
FireAngel ST-622:
https://www.safelincs.co.uk/fireange...k-smoke-alarm/
--
Peter.
The gods will stay away
whilst religions hold sway