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Emergency Lighting - Invisible (fine grid) results in brackets and the necessity

Hi,


I'm running an emergency lighting calculation and I am puzzled by necessity to include the results of an invisible grid in brackets, I can understand that they are results which are based on a fine grid and will often provide more accurate results although this fine grid is not view-able or adjustable, I cannot find any part of EN12464 that insists on the grid being below 0.5m and the inclusion of this increases the calculation time.  Is there any way to turn the calculation of the fine grid off or at least view the fine grid so I know the location of the shortfall in illlumiance?


Regards,


Luke


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Dear Luke Harrington


Maybe it'll help you, if i tell you, that the grid is adjustable.


Click on your Emergency Area --> Calculation --> Calculation Parameters --> and Remove the checkmark. 


I hope thats solves your Problem.


Regards,


Relux Informatik AG
Basile Schlegel
Relux Support

Hi,


Thanks for getting back to me (better late than never).  Unfortunately you seem to have misunderstood my enquiry. Please see the below image:


image



When you produce an emergency calculation in Relux, there are 2 different calculations which are calculated within the same emergency measuring surface, if you look at the above results, you can see that there is a minimum level of 1.4 lux although the fine measuring grid provides a level of 0 lux.  The method of adjusting the calculation points you have provided only refers to adjusting one of the two grids I have mentioned, it's the figure in brackets that I was referring to as I mentioned in my first post.  The fine measuring grid (the figures in brackets) tells me that I have a minimum value of 0 lux although the grid that I have placed (and I'm able to adjust) gives me a figure of 1.4 lux, I'd like to remove the figure in brackets which is invisable, non-adjustable, for which you provide very little information of and is unnecessary to have on every emergency design.


Regards,


Luke

Dear Luke Harrington


The fine measuring grid is necessary to understand the pseudo colours wich the calculation results are based on.
If there is a large difference between the first and the second value, its possible to finde the cause into the pseudo colours. It ussually happens because there is a dark corner without any light. In this case there are possibilitys to adjust the light or the emergency area.
By removing these calculation results, important information would be missing.


Regards,


Relux Informatik AG
Basile Schlegel
Relux Support


Hi,


Thanks again for your reply.


I understand that the fine grid calculation is more thorough, and being more thorough is often better and more accurate, although this method does not allow you to view the individual calculation points, only psuedo colours which provides only an approximate area where the level falls below the minimum  requirement, and if it is in a large room with a lot of objects taking the first inter-reflection into account, the invisible grid that is non-adjustable creates a HUGE delay to the calculation, and because there is nothing in the EN12464 standard which tells us that the calculation points need to be below 0.5m apart, it is unnecessary.


I'd argue that important  information would not be missing if the invisible grid is excluded from the calculation, as I have inserted an emergency grid with sensible spacings which are still in line with EN12464, so this non-adjustable grid is only providing information which cannot be viewed in detail and is actually counter-productive to the design as it is taking additional hours to let me know information which I find to be unnecessary.


I realise that this is a matter of opinion and I'm satisfied with your answer, although I am disappointed that Relux lets itself down in this area, of course I will always try to achieve the minimum requirement on both the invisible grid and the visible grid, although due to the calculation time it would be more useful to calculate only the visible grid at least until the final calculation, as taking 4 hours to calculate every point in a 20,000m² room using obstructions only to find out that you need to re-calculate because the corner of the room is slightly under is frustrating and time consuming.  I will continue to use Relux as I am a big supporter, although I may have re-consider the way I calculate emergency lighting.


Thanks,


Luke

I believe that this is saying that for points between 0 and 0.5 metres it is not possible to calculate any results as EN12464 states that the grid is to be on 0.5 metre intervals. Therefore the calculation will show a 'null' result as it falls below this level.

  So the point is still valid. why have it in the first place?!

Dear Bernard Glossop,


You misunderstood me, if you have a value below 1lx in the result overview, then this is usually because there is an area at the edge of your room which is not sufficiently illuminated. 

The fine grid, which is displayed as a pseudocolor, shows this dark area pink colored.



Within the table you will find other numbers, beacause this calculation grid is not that fine. But the lowest numerical value is still written, as you can see in the picture below.


Best regards,


Relux Informatik AG

Basile Schlegel

Relux Support



It does not solve my problem unfortunately, I still feel it is a bad inclusion to the program and it would be far better off without displaying/calculating that information, although I feel (as I did 7 months ago) that we are at an impasse... Relux feel that it is essential to include this information and I very much feel as though it is not, as a good lighting designer will always use sensible spacings anyway.


For example, the screenshot you have shown above details a calculation grid that displays spacings below 0.5m apart, with a minimum illuminance level of 0.6 lux, and there is a seperate figure (of which you cannot view as individual points - only a psuedo colour image) of 0.5 lux, now if the calcuation grid already contains calculation points which are below 0.5m, why would you need a second figure detailing calculation points which are also below 0.5m apart?

EN12464 does not require calculation points below 0.5m to the edge of the area being calculated. So why calculate them? This implies that the program (app?) is calculating within this zone. The 'fine measuring grid' (0.1/0.2/0.3/0.4 metres?) are being taken into account and this is not a requirement of the standard. The 'fine measuring grid' is made up by Relux!

Dear Bernard Glossop


When we talk about emergency lighting, we have to check what is written in EN1838 (2014). Unfortunately, these papers do not provide us a standardized measuring grid which we can use for our emergency calculation.

It is only pointed out that this area must be illuminated with at least 1lx, apart from the border zone. Now it is impossible to know where the measurement will actually take place. Because of this lack of information, we use a fine grid for our calculation so you can be sure that you comply with the standard.

We can understand your issue, but if someone verifies your lighting calculation, you probably won't have any problems.



Best regards,


Relux Informatik AG

Basile Schlegel

Relux Support




For those English speakers amongst us:


BS EN 1838:2013

Lighting applications — Emergency lighting


"4.2 Escape route lighting


4.2.1 For escape routes up to 2 m in width, the horizontal illuminances on the floor along the centre line of

an escape route shall be not less than 1 lx. The central band consisting of not less than half of the width of the

route shall be illuminated to a minimum of 50 % of that value. Wider escape routes may be treated as a

number of 2 m wide strips or be provided with open area (anti-panic) lighting."


I think that the point here is that as long as this rule is met then anything that falls outside of the 'not less than half of the width of the

routearea does not matter (0.5>0 lux). May be the escape route measuring area requires a 'task area' and a 'perimeter area' based upon the above.


In an open area (office) the standard states:


"4.3 Open area lighting

 

4.3.1 The horizontal illuminance shall be not less than 0,5 lux at the floor level of the empty core area which excludes a border of 0,5 m wide of the perimeter of the area."


A similar state of affairs has already been built into this regulation by the fact that a 0.5m border has already been defined, and the level of illumination does not matter beyond this to the room border.


So, from the above,

corridor 0.9 metre wide would have a 0.225m exclusion zone to the corridor border,

A corridor 1.2 metre wide would have a 0.3m exclusion zone to the corridor border,

A corridor 2 metre wide would have a 0.5m exclusion zone to the corridor border, the maximum permitted under the Standard,


Your ongoing thoughts would be appreciated!

Dear Bernard Glossop


"I think that the point here is that as long as this rule is met then anything that falls outside of the 'not less than half of the width of the route' area does not matter (0.5>0 lux)."


I completely agree with you and for this reason we no longer calculate two metre wide escape routes. New, the illuminance level should not be less than 0.5lx within one metre and not less than 1lx along the centre line.

In the picture below the measuring points are highlighted in red if the illuminance on this line is below 1lx.


And I also agree with you, if the corridor doesn't have a width of 2 meters, you are allowed to reduce the width of your measuring surface as well.


Best regards,


Relux Informatik AG
Basile Schlegel

Relux Support



Basile


So if we are now all agreed would it not be possible to insert a measuring object for an emergency area to take this into account? Picking the areas of the space being illuminated could create an emergency area with the 0.5m maximum boundary being taken into account, or at least an option in 'position' to allow the user to do this. If one has a polygonal measuring object, offsetting it by 0.5 metres to the room perimeter accurately is in my view difficult. Unless, of course, I am doing this incorrectly!

Dear Bernard Glossop


This is an interesting proposal, we will discuss it internally and see whether and how we can implement it.

Best regards,


Relux Informatik AG
Basile Schlegel

Relux Support

Jolly good!


mit freundlichen Grüßen

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