Re: Advice on sensors, please

["Frank Olson" <feolson@xxxxxxxxxx>]

"Old Dad Smith" <oldmistersmith@xxxxxxxx> wrote in message
news:1119632141.682075.218870@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Frank Olson wrote:
>> Poor layout.  You've got motion sensors looking at south facing windows.
>> You've got no contacts on other entry doors which will restrict your use
>> of
>> the system while you (or your family) are at home.  A PIR of any sort in
>> the
>> kitchen isn't required unless you're using gold faucets.  Taking out #3,
>> and
>> moving #1 to the South east corner of the dining room would be better.
>> You'd cover a good portion of the kitchen there as well.
>
> OK. Thanks for your advice, Frank.
>
> How for away from the radiator should a PIR sensor be? Do you have any
> views on ceiling mounted PIRs, given the number of radiators in the
> corner of each room?

Infra-red is "infra-red".  It doesn't matter how far away the sensor is,
it's going to see quite a heat "bloom" when your radiators come on.  You may
have to selectively mask the detector from seeing that part of the
protection pattern (I would highly recommend never mounting a PIR right
*over* a radiator though).  These days with the multiple layers of
protection most sensors "see", that's not hard to do (albeit a bit time
consuming).  I'd stick with a good Digitial PIR like the Paradox line
(http://www.paradox.ca).  I've never experienced a false alarm with this
detector due to a room's "environment".  You just have to follow good
installation practice and test, test, test...

Ceiling mounted PIR's probably won't give you the protection coverage you
want.  They're even more "finicky" to set up and position correctly.

Good luck!!!