PIR placement

[SaladFingers]

Obviously with PIRs, there's a guide (with mine anyway) to the placement and where not to point them, but could some of the experienced here advise me on the best places to point them and the most silly places not to point them? I take it pointing towards glass (door or window) might be a bit silly?

In particular, not above a radiator, but how close to a radiator can I get?

 

[libby lou lou]

I have one passive facing my front windows and one at the rear facing a window that used to be patio doors, never had a problem, they are getting on a bit now though.

 

[SaladFingers]

Interesting. At the moment I'm trying to decide wheather to face my PIR out of the room which will mean the distance from the side of the PIR and the convecting central heating radiator will be 500mm - or face it into the room towards the radiator and window.