I read a post recently about not sitting a PIR facing Windows

little embarrassed but i didn't know this. I understand the white light and direct sunlight thing. But where does it say i cant place a PIR facing windows. I have them everywhere without FA. Irealy need to know if im going to stop.

Jef

Hi Jef,

It's more of a guideline than a rule.

In general the problem comes from direct sunlight or car headlights shining through the window and hitting the PIR rather than the window itself.

The ideal "recommended" position would normally be with the PIR mounted internally on an outside wall facing into the room, so that the zones terminate on furniture or internal walls. Of course this is not always possible and there are certainly many installations that do have PIRs facing windows without any problems.

A north facing window with a garden outside will be less of a problem than a south facing window with a busy road junction outside. If there is a chance that sunlight or car headlights could hit the PIR and there is nowhere else to site it then a dual-tech will be a better option.

Of course if a window is particularly drafty then that could also lead to false alarms if a PIR is pointing at it.

For conservatories I would generally recommend using a dual-tech, and again if possible face it towards the building in a position where white light cannot hit it.

As for your existing installations, if they are not causing any problems I certainly wouldn't worry too much about changing them. But for future installations if you can avoid windows in the coverage area then it could only be a good thing.

Hope this helps.

Mark

Edited October 25, 200421 yr by Mark Pitts

Mark

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Many thanks for a prompt answer, will cary on installing as normal then.

Much appreciated

Jef

I point dets at windows all the time without fas Jef

Pete

I thought additional idea of PIR not facing windows was to hide them from potential burglars view too, but I might be wrong?

I point dets at windows all the time without fas Jef

Pete

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I NEVER face them at windows, white light filter or not.

Regards

Bellman

I point dets at windows all the time without fas Jef

Me too, I think that this white light and car lights problem is hardly relevant to any detector made in the last 10 years, they all have white light filtering as standard now. It shouldn`t be a problem.

Yup, agreed.

As far as I'm aware, PIR's will only FA due to sunlight if hit directly by sunlight.

There are thousands of shops with full glass fronts with PIR's that don't FA.

Conservatories are generally fitted with Dualtechs dur the the extreme heat more so than the direct sunlight, Ithought.

I try and face the detector inwards if i can but not always possible due to room layout, radiators ect, but every decent detector nowadays has a white light filter and seems to me that it does its job.

Always pointing at windows, thats where the scrot gets in, never had a problem with RX40.

Alot of this comes from the days of microwave detectors that could pick up through glass and it stuck.

Anybody had a observation from the NSI / SSAIB for the siting of a detector other than installed in the rear left when its the rear right,

Rich

Jeff.....now youre posting early.

Edited October 25, 200421 yr by Nova-Security