PIR in a 3 season porch

[yacobid]

I am trying to secure my aprox 20'x20' 3 season porch.  As this is the easiest access to the house and to the rear and private I want to make sure to do it right. 
 
The plan is to install a wired reed switch on the outside door to the porch, and another on the door into the house.  I also wanted to install an outdoor PIR in the corner facing the one wall without windows and possibly a glass break detector. When  I get the automation going I want to install a IR Gate at the stairs going up the porch with will turn on the lights inside the house.
 
My concern is with almost floor to ceiling windows on 3 sides and an outdoor PIR which tends to have longer range am I increasing my chance of false alarms.  The manuals suggest not facing the PIRS towards windows. Are there any suggestions ?

 

[Big517]

Dig a moat, fill it with sharks with laser beams on their heads.

If your not up for that, the pirs in the inside would be ok if they are decent quality but you will find them convenient on the automation side. I would still go with one that will hit the majority of the room, And the glass break for sure but also get that beam outside to trip if someone is approaching and then a flood light to turn on. Make sure you turn a light on outside if the exterior is tripped. You don't want to fill your room with light and not see who is outside that may encourage a breach. Personally I would only illuminate the tripped area and maybe another light randomly in the house with a few second delay to emulate "someone in the house knows im here". That way you can see them but they cant see you.

I have over 20 pirs in my house with a lot of glass. No falses. Using honeywell / ademco 35' pet immune with the lookdown cover removed and sensitivity all the way up.

 

[yacobid]

Thanks Big I didn't even consider I wouldn't be able to see out if I am in the lit room.  
 
I came across another question installing the inside PIR, Id like to stick it in the corner of the room but Im wondering if the curtains that will partially block its view will make it "blind" to the angles its blocked by the curtains 

 

[Del91574]

FWIW, I did an install way up in NH about 3-4 years back, and given the weather we've been having the last couple of weeks (0 or below 0 at night) and the install being in for those years, I've never seen a false come from that account from enviromental (them opening their slider into the room,programmed as perimeter, different story).
 
If you're talking closed space, windows and sealed from insects, you might get away with a good quality motion to protect the space, but what your definition of 3 season may be might not be the same as what I call it.