photocontrol face north?

Reply

  #1  
Old 11-19-10, 02:31 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,918
Received 4 Votes on 3 Posts
photocontrol face north?

It seems all the instructions for mounting/positioning an outdoor lighting photocontrol mention to try to face it in a northerly direction. Why is that? What's the reason/explanation for wanting it to face north if you can?
 
  #2  
Old 11-19-10, 02:46 PM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,614
Received 98 Votes on 86 Posts
The sun shines from the south

Need more or are you getting it now?
 
  #3  
Old 11-19-10, 04:55 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,918
Received 4 Votes on 3 Posts
Originally Posted by mitch17 View Post
The sun shines from the south

Need more or are you getting it now?
No, I don't get it. I thought the sun rises from the east and sets in the west. I don't understand what is meant by it "shines" from the south. And even it it does, I don't understand how that means it would be best to mount a photocontrol facing the north.
 
  #4  
Old 11-19-10, 05:37 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
Assuming that all directions have an open view to the horizon the east-facing photocell will turn the lights off early and turn them on early. The west-facing photocell will turn the lights off late and turn them on late. A north-facing photocell will split the difference.

As an example, the photocell controlling my outside lights faces west. As a result it is fairly dark on the north and east sides of my house before the lights come on in the evening and it is quite light in these areas before the lights go off in the morning. I do not have an open view to the east but have quite a stand of tall trees so I am planning on moving my photocell to the east (actually NNE) so that my lights will come on earlier in the evening and go off earlier in the morning.

The above, of course, is for my location in Washington state, USA.
 
  #5  
Old 11-19-10, 05:43 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,582
Received 13 Votes on 11 Posts
But by the same reasoning wouldn't south also split the difference? So is North just an arbitrary choice where either would give the same result or is it a matter of axis tilt.
 
  #6  
Old 11-19-10, 05:58 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,918
Received 4 Votes on 3 Posts
Then I guess a lot of variation can come into play, depending on how many, and if any, of the directions might have some particular extent of an open view to the horizon from where the photocontrol is mounted and is facing. Also, I was wondering too what ray2047 just asked about North being arbitrary and whether South would give the same result??
 
  #7  
Old 11-19-10, 06:42 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,965
Received 6 Votes on 6 Posts
Being in the northern hemisphere, the sun tends to track east to west in a southerly motion. The sun will shine on the photocontrol longer in a southerly facing than it will in a northern. You don't want sunshine, but "light". Light is more gentle from the north.
NOW, if you are in the southern hemisphere, reverse everything, except the east/west thingy.
 
  #8  
Old 11-19-10, 06:42 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
South would work well if you are located south of the equator. The reason for north is that in the northern hemisphere the sunlight does indeed come from the south, at least in the winter months, as Mitch pointed out. Having the photocell pointing south would turn the lights off sooner in the morning and on later in the evening and leave the northern, and to a lesser extent the eastern and western sides of the building in darker conditions when the lights would be on if the photocell is pointing north. Of course these conditions are more pronounced the farther north you are and will also be opposite if you are in the southern hemisphere.

The bottom line is that there is no "perfect" location or orientation for a photocell controlling outside lighting. If you need perfection then you need to use an astrological time switch as I suggested in a different post.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: