Door/window contact vs PIR on Yale system

[tommy8884]

Hi,

This is my first post in a while so go easy

I am about to purchase a Yale wireless premium alarm. I plan to use 1 door contact for entry on the front door and 1 contact in the detached garage. I plan to use 1 pir in the entrance hall facing away from the door and another on the upstairs landing.

I intend to purchase one more pir for the living room.

My question is how good are the door/window contacts. My kitchen and conservatory need covering and I do not know to use a pir or contact. My concern with the contact is that if the window is smashed, the contact would be in tact and the alarm would not sound.

I am not too worried about the conservatory as that leads to the living room which will be covered by the pir. There is also a window to the living room.


Just a note, reading around I have noticed that these subjects can be controversial. I don't want to start a war on wireless alarms. I have made my mind up on that. I would just like advice on using pirs or contacts.

Thanks in advance

 

[securit]

Do you mean the window of the front door may be smashed, if so why not remove the DC, and point a PIR at it instead,

 

[chaindaisy]

Hi Tommy,

May I just quote you on this. " ..... Just a note, reading around I have noticed that these subjects can be controversial. I don't want to start a war on wireless alarms. I have made my mind up on that. I would just like advice on using pirs or contacts... "

I'll hazard a guess and suggest that you have been reading some of the posts. Good on you for telling it like it is.

Securit needs a little more information from yourself before forming an opinion and I reckon that's fair comment.

The first thing we should establish is that any prospective intruder has no way of knowing what your security set up really amounts to unless he has been inside your property and seen first hand. In other posts I tend to suggest that " ... when you have installed a security system the what if's pass from you to the burglar. It is up to him to worry about the 'what if's and not yourself ...". But I can understand your concern.

A passive infra red pointing toward that weak point is most certainly worth while as mentioned in the previous post. However, consider the 'aspect'. This simply means the location of the glass, whether it is pointing in a south or south westerly direction. During the summer, when we get one, the glass heats up and may give rise to a false alarm... this often occurs during late afternoon on a particularly warm day when the sun has been there for a few hours. Anyone who tells you different is totally wrong. The solution here may be to aim the passive infra red lower so that it is not centred on the glass but will nevertheless pick up an intrusion from that direction, other options are the use of roller blinds and so on. It may never happen in your case but you should be aware of it.

A door contact is a wise investment, in fact the more the merrier, (not every door is smashed in, some intruders are quite courteous and simply open the door - and the alarm sounds) but with wireless there may be some cost restrictions and too many could stretch the budget too far. I am not sure about the cost at this point so excuse me on that one.

If you can, try and spread your budget so that there is a fairly even distribution of both types throughout the premises. The good thing here is that you can always add to the system when you've got a few quid spare in the future.

I haven't particularly answered your question regarding which of the two is the better option, although most people tend to go for the passive infra red unit, since it depends on the layout of the property and only yourself can make the informed judgement.

Keep us informed and let the forum know if you actually do need specific details of what each detector is capable of and it's limitations.

Take care.

 

[Europlex]

Just a note, reading around I have noticed that these subjects can be controversial. I don't want to start a war on wireless alarms. I have made my mind up on that. I would just like advice on using pirs or contacts.

Wireless or not, wars or not, it is not recommended to point a PiR AT a front door.
(Too much post)

Put it in one of the two corners either side of the front door.
Look at the manual that you have, there you will find a diagram showing the area covered by PiRs.
You will get better cover as PiRs are designed to detect when someone walks across their area of cover, not towards the PiR itself.

 

[bernardgreen]

What about putting the PIR on the inside of the door. As the door opens the "image" the PIR sees will change as the PIR moves with the door.

The images of any static heat sources ( radiator lamp etc ) will move across the PIR's sensor and trigger motion detected. A low wattage table lamp would almost certainly ensure detection of the door moving.

If there are no static heat sources the intruder may be detected as (s)he closes the door.

 

[Europlex]

What about putting the PIR on the inside of the door. As the door opens the "image" the PIR sees will change as the PIR moves with the door.

The images of any static heat sources ( radiator lamp etc ) will move across the PIR's sensor and trigger motion detected. A low wattage table lamp would almost certainly ensure detection of the door moving.

If there are no static heat sources the intruder may be detected as (s)he closes the door.

What planet are you on?

I suggest you go away and find a forum that deals with a subject that you know about as you obviously know nothing about the workings and practicalities of PiR detectors used in the security industry.

I'll end my contribution here, I've said it all, there is no need for me to get into a protracted thread with someone who will never agree he is wrong.

Edit.

Apart from anything else, who on Earth would want a PiR fitted on the inside of their front door?

 

[chaindaisy]

Hi Tommy,

The last few posts are simply contentious issues and not relevant to your query. You would be well advised to ignore anything which serves to detract from your original question. With no other alternative, I have installed a passive infra red within two metres of a main door, that was several years ago. The system is fine and the passive picks up immediately. Be prepared for posts which are simply 'ego builders' which ultimately waste their own time and do very little, if anything, to further your own cause.

Best Wishes.

 

[Europlex]

Hi Tommy,

The last few posts are simply contentious issues and not relevant to your query. You would be well advised to ignore anything which serves to detract from your original question. With no other alternative, I have installed a passive infra red within two metres of a main door, that was several years ago. The system is fine and the passive picks up immediately. Be prepared for posts which are simply 'ego builders' which ultimately waste their own time and do very little, if anything, to further your own cause.

Best Wishes.

Please tell me then what here is contentious then >>>

1. securit > if so why not remove the DC, and point a PIR at it instead

2. bernardgreen > What about putting the PIR on the inside of the door. As the door opens the "image" the PIR sees will change as the PIR moves with the door.

Both those two bits of 'help' are wrong.

And I had respect for you chaindaisy, I thought you knew what you were talking about, I am very obviously wrong.

I'm sure you do know what is so wrong with these two bits of advise, don't you?

 

[chaindaisy]

Hi Tommy,

Please ignore the last post, it is not relevant to your oriiginal query.

Thanks.

 

[JohnD]

I reckon it is best to havea Door Contact on any door that people are likely to open to get into the house. You can if you wish use it as an Entry sensor to start the countdown when someone comes in, and you can if you wish set it to chime when the door is opened to alert you. This us especially useful if a door is left unlocked during the day and you might not be able to see it.

I have set my back door and garage doors to chime whenever they are opened.

Putting PIRs so they look "across" a doorway or window, so they will "see" someone coming in, means they detect movement faster than if they are pointed directly at it.

I have had PIRs that can see table lamps and letterboxes, and they have never been triggered by the lights going on and off with timers, nor by letters or packets coming through the door. However I am prepared to believe that it might happen.

 

[bernardgreen]

I am not "in the security business" but have been involved in security system when interfacing a security system to a paging system where the paging system covertly informs security staff of the exactl location of the break in.

Detection of a door being disturbed can be done in many ways. The most common methods as used in the average alarm system require the door to be partially opened before detection can occur. The more unusual and often more effective / sensitive methods seldom get used in average systems but can detect attempts to open the door before it starts to open.

 

[chaindaisy]

Well done John D, a really helpful bit of advice there. That's what Tommy is looking for... help and advice.

Well Done.

 

[bernardgreen]

I have had PIRs that can see table lamps and letterboxes, and they have never been triggered by the lights going on and off with timers,

If the lamp is stationary relative to the PIR then there is no motion in the PIR's view so a good PIR will not be triggered. But if the lamp or the PIR's field of view moves then the lamp is moving in the image as seen by the PIR and the PIR will ( should ) trigger.

 

[chaindaisy]

Last post is irrelevant since the author is attempting to enlighten Tommy on the finer electronic aspects, which Tommy doesn't need at this point in time.

 

[Europlex]

I reckon it is best to havea Door Contact on any door that people are likely to open to get into the house. You can if you wish use it as an Entry sensor to start the countdown when someone comes in, and you can if you wish set it to chime when the door is opened to alert you. This us especially useful if a door is left unlocked during the day and you might not be able to see it.

I have set my back door and garage doors to chime whenever they are opened.

Putting PIRs so they look "across" a doorway or window, so they will "see" someone coming in, means they detect movement faster than if they are pointed directly at it.

I have had PIRs that can see table lamps and letterboxes, and they have never been triggered by the lights going on and off with timers, nor by letters or packets coming through the door. However I am prepared to believe that it might happen.

Yes.

If you have a look at any manufacturer literature about PiRs there will be a schematic showing the area of cover given and the best positions to fit.

None of them will suggest fitting on a door so that opening the door will activate the alarm. That is not what they are designed for.

Apart from anything else I would suspect a good slam of the door would damage the PiR, or at least cause a tamper fault as the lid pops off.

Any way, would you want one of them stuck, sorry, screwed on your front door with a flexible door loop using two junction boxes also. You have to get a cable there some how and alarm cable is not designed as flexible