PIR Sensor and CH flue
 

Hi there,

I have recently installed 2 floodlights that are to be controlled by an
independant sensor. I am having major probs with the sensor sensing
the exhaust fumes every time the boiler is used.

The sensor is located approx 4ft from the flue outlet at a right angle
so te flue blows in the direction of the sensor. I have moved the
sensor higher up and today built a metal shield around the flue to vent
the fumes upwards all to no avail.
I can't really move the sensor elsewhere as it's current location is
the best spot for it to pickup any 'dancing bears' (from a previous
post!)

I would appreciate any suggestions on how this problem can be tackled.

Msny thanks

Naz

can you locate the sensor so that it is detecting the area lower than the
flue. i.e. not looking at the 'hot' emmisions from the flue.


woodglass...

"nazn" wrote in message
ups.com...
Hi there,

I have recently installed 2 floodlights that are to be controlled by an
independant sensor. I am having major probs with the sensor sensing
the exhaust fumes every time the boiler is used.

The sensor is located approx 4ft from the flue outlet at a right angle
so te flue blows in the direction of the sensor. I have moved the
sensor higher up and today built a metal shield around the flue to vent
the fumes upwards all to no avail.
I can't really move the sensor elsewhere as it's current location is
the best spot for it to pickup any 'dancing bears' (from a previous
post!)

I would appreciate any suggestions on how this problem can be tackled.

Msny thanks

Naz

nazn wrote:
Hi there,

I have recently installed 2 floodlights that are to be controlled by
an independant sensor. I am having major probs with the sensor
sensing the exhaust fumes every time the boiler is used.

The sensor is located approx 4ft from the flue outlet at a right angle
so te flue blows in the direction of the sensor. I have moved the
sensor higher up and today built a metal shield around the flue to
vent the fumes upwards all to no avail.
I can't really move the sensor elsewhere as it's current location is
the best spot for it to pickup any 'dancing bears' (from a previous
post!)

I would appreciate any suggestions on how this problem can be tackled.

Msny thanks

Naz

fit a condensig boiler....colder flue, less likly to triger pir. even
better is if you install a long flue at the same time as the boiler's fitted
to divert flue gases upwards rather than straight out.

downside is cost. but at least your less likly to be burguled and lower gas
bills!

steve

"nazn" wrote in message
ups.com...
Hi there,

I have recently installed 2 floodlights that are to be controlled by an
independant sensor. I am having major probs with the sensor sensing
the exhaust fumes every time the boiler is used.

The sensor is located approx 4ft from the flue outlet at a right angle
so te flue blows in the direction of the sensor. I have moved the
sensor higher up and today built a metal shield around the flue to vent
the fumes upwards all to no avail.
I can't really move the sensor elsewhere as it's current location is
the best spot for it to pickup any 'dancing bears' (from a previous
post!)

I would appreciate any suggestions on how this problem can be tackled.

Msny thanks

Naz
Are you sure that the PIR is being triggered by the hot flue gases or is it
being triggered by the boiler spark affecting the electronics of the PIR?
Just a thought! it may be worth eliminating before you take any expensive
action.
Otherwise use a different type of sensor, must be cheaper than a new boiler.
Tom

I am not too sure about the boiler spark triggering the sensor, the
boiler is quite old and has a permanent pilot rather than a spark
thingy (sorry I don't know what this device is called but know what
you mean...I think). I am not the market for a new boiler, if I was
then it would be the condensing type, then again slightly off-topic...
what's the average to get a return on a condensing boiler?

I have also considered moving the sensor lower than the flue outlet,
but this would be too low and IMO an easy target for anyone to get at
it (less than 2m). This unfortunately seems to be my only option,

Many thanks
Naz

On 9 Sep 2005 16:22:26 -0700, nazn wrote:

I am having major probs with the sensor sensing the exhaust fumes
every time the boiler is used.

Mask of the parts of the lens that look in the direction of the flue?
Bits of insulating tape on the inside should do it.

--
Cheers
Dave. pam is missing e-mail

Your PIR is looking for a moving heat source, the exhaust from your boiler
is a moving heat source, you have to stop the sensor seeing the area where
the exhaust flows before it cools (in all wind conditions) this will mean
moving or masking of the PIR.(unless of course you fancy moving the boiler)

"nazn" wrote in message
ups.com...
Hi there,

I have recently installed 2 floodlights that are to be controlled by an
independant sensor. I am having major probs with the sensor sensing
the exhaust fumes every time the boiler is used.

The sensor is located approx 4ft from the flue outlet at a right angle
so te flue blows in the direction of the sensor. I have moved the
sensor higher up and today built a metal shield around the flue to vent
the fumes upwards all to no avail.
I can't really move the sensor elsewhere as it's current location is
the best spot for it to pickup any 'dancing bears' (from a previous
post!)

I would appreciate any suggestions on how this problem can be tackled.

Msny thanks

Naz

Dave Liquorice wrote:
On 9 Sep 2005 16:22:26 -0700, nazn wrote:

I am having major probs with the sensor sensing the exhaust fumes
every time the boiler is used.

Mask of the parts of the lens that look in the direction of the flue?
Bits of insulating tape on the inside should do it.

Insulating tape may be transparent in the IR - comes from the pigment
being well under the wavelength of the IR.
Metal backed tape will totally obscure it.

However, simply pointing the PIR away may work.

I am now considering moving the PIR further down the building, this
will however mean part of the side fence will not be covered by the
PIR. This will be approx 1.5m from the flu with the sensor pointing
away from the flue.

Thanks for all the suggestions

Naz