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Topic Title: Freezer room and fluorescent lights
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Created On: 29 April 2010 01:01 PM
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 29 April 2010 01:01 PM
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misterben

Posts: 438
Joined: 11 June 2007

Hi all,

I have been asked to reduce the power consumption in a freezer room which runs at - 20 degrees they currently have Metal Halide fittings which are left on pretty much 10 hrs a day. These are accessed a handful of times a day maybe in for 5 -10 mins at a time 3 0r four times a day. Am i right in believing that fluorescents will be very inefficient in these temperatures? If so anyone have any ideas, other than asking them to plan ahead and ultimately remember to turn them off and wait for cool down and warm up periods


regards

Misterben
 29 April 2010 01:11 PM
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OMS

Posts: 22864
Joined: 23 March 2004

Just use a luminaire with a cold start ballast and lamp oversleeves.

Try a google for Thorn Coldforce for example.

Presumably you also need a "food grade" luminaire as well

Regards

OMS

-------------------------
Let the wind blow you, across a big floor.
 29 April 2010 01:46 PM
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gizmo

Posts: 18
Joined: 27 April 2010

Stienel make a Pir that will operate at coldroom temperatures as for the actual lighting we use led tubes and convert standard fittings to suit the lamps

google ledecolights

not cheap but effective for the job
 29 April 2010 02:18 PM
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OMS

Posts: 22864
Joined: 23 March 2004

not cheap but effective for the job


In my experience, neither cheap nor effective.

Installing an LED array in a luminaire designed for a tubular MCF emitting light in all directions tends to totally upset the photometry as the LED string tends to be much more directional and as such cannot project onto the reflector. The direct component of the LED tends to be less than the total component of the MCF lamp in terms of lumen output so overall, I suspect the T5 MCF is more efficient

Regards

OMS

-------------------------
Let the wind blow you, across a big floor.
 29 April 2010 02:54 PM
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broadgage

Posts: 3170
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Flourescent lamps perform very poorly when cold, and the new T5 ones seem worse in this respect.
Flourescent tubes are available with an over sleeve to retain the heat, these work well once the lamp has warmed up, but dont help initialy since an unlit lamp is still at -20 and will give very little light until warmed up. Therefore no good for PIR switching or turning on when required.

I would suggest either mains voltage halogen lamps in enclosed bulkhead fittings, or LEDs.

Although mains halogen lamps will use very roughly 4 times the power of metal halide for the same light, that could produce a saving if the halogen lamps are lit for an hour a day compared to 10 hours for the metal halides.

Alternatively consider LEDs, several manufactureres now make LED street lights, and something similar could be considered, they are more efficient at low temperatures.
I doubt however that the capital cost would be justified for only short term use.
 29 April 2010 03:30 PM
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misterben

Posts: 438
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Thanks for the info everyone, I am intending to use a door switch rather than a PIR. The fittings will be Non corrosive HF everywhere else in the production area.
Can I literally replace the tubes in a switch start or HF fitting with LED tubes?
I have googled them and they are quite expensive but we have a reasonable budget, just need to make an energy saving and achieve a reasonable light output.


regards

Misterben
 29 April 2010 03:42 PM
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OMS

Posts: 22864
Joined: 23 March 2004

Can I literally replace the tubes in a switch start or HF fitting with LED tubes?


A 1200mm LED replacemnt lamp will operate at 15W and emit 1000 Lumens

The equivalent fluorescent will consume 28W and emit 2900 lumens

So an 86% increase in energy consumption gives you a 190% increase in light output. Go figure

In my opinion, they are not like for like replacements unless the original installation was significantly overlit for the task.

A colleague of mine is acting as expert witness in a case where a guy was seriously hurt at work (forklift injury). The FM manager had recently replaced a large number of T8 lamps with LED conversions - despite complaints that the lighting levels had dropped significantly he wasn't going to change them back due to the cost involved - it's gonna be an expensive mistake when a judge decides he had breached obligations under health and safety legislation and effectively contributed to teh incident by reducing light levels below a safe threshold by his actions.

If you have a reasonable budget I would consider induction lamps - try something like the Chalmor "Endurance "Range

Regards

OMS

-------------------------
Let the wind blow you, across a big floor.
 29 April 2010 04:45 PM
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misterben

Posts: 438
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I have gathered some info on the ecoled as suggested and they are expensive but have been assured that in an average height room of 3.5M a like for like tube will give produce the same lux level.
I am tempted to trial them in an area to find out as they offer a trial period, they seem like the best solution in the cold room and also come with a long guarantee. Also spoke to Chalmor, thanks OMS.
What do you all do when buying gear of some value? Internet or local wholesaler? Maybe the internet based companies dont offer the same product support, or maybe I am being too loyal to my local wholesaler!

regards

Misterben
 29 April 2010 04:53 PM
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TeesdaleSpark

Posts: 707
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You can get linear fluorescent lamps designed for low temperature use: Aura THERMO.
 29 April 2010 05:12 PM
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OMS

Posts: 22864
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I have gathered some info on the ecoled as suggested and they are expensive but have been assured that in an average height room of 3.5M a like for like tube will give produce the same lux level.


How can that be the case - I took the figures above from the manufacturer that Gizmo highlighted. Thier 1200mm replacement LED only produces 1000 Lumens (and is quite directional) - the equivalent T5 produces 2900 Lumens (nearly 3 times the output) with an increase from 15W to 28W

It may be giving you an equivalence in terms of watts/m2/100 Lux but it certainly isn't giving you the same light output - how can it if it doesn't have the same lumen output.

Illuminance(E) = (lamp lumens x n x N x mf x uf) /area m2

Where:
n is lamps per luminaire
N is number of luminaires
mf is the maintenance factor
UF is the utilization factor

If you presume that MF and UF are the same in both cases (say 0.78 and 0.38 respectively) then plug in the numbers and see what "E" comes out at

Regards

OMS

-------------------------
Let the wind blow you, across a big floor.
 29 April 2010 05:17 PM
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misterben

Posts: 438
Joined: 11 June 2007

Yes I see what you mean, I realise these people will sell you anything then leave you with a problem. I will get them to bring some to site and try them out they have a 14 day trial or a rep will bring them down. Nothing to lose really
Thanks guys seems I have 2 options LED or Teesdale sparks thermo long life


regards

Misterben
 29 April 2010 05:22 PM
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OMS

Posts: 22864
Joined: 23 March 2004

Thanks guys seems I have 2 options LED or Teesdale sparks thermo long life



LoL - or God forbid you could take the third option and employ a competent lighting designer of course

Good Luck

OMS

-------------------------
Let the wind blow you, across a big floor.
 30 April 2010 12:59 PM
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gizmo

Posts: 18
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If you are going to use a door switch rather than a pir/s I would consider wether or not the coldroom door could be closed whilst someone is in there resulting in complete darkness, is emergency lighting currently installed?

also slightly off topic but is an entrapment alarm installed?

just a few things to consider also (sorry if I am pointing out the obvious to you)
 30 April 2010 01:10 PM
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gizmo

Posts: 18
Joined: 27 April 2010

Originally posted by: Misterben

Can I literally replace the tubes in a switch start or HF fitting with LED tubes?
Misterben



for an led tube from ecolights (don't know about others) modification to a standard fitting is required, the led needs live to one endcap and neutral to the other endcap of the fitting , ballast etc are not used
 18 June 2010 11:23 AM
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broadgage

Posts: 3170
Joined: 07 August 2007

Originally posted by: TeesdaleSpark

You can get linear fluorescent lamps designed for low temperature use: Aura THERMO.


I dont believe that these will be suitable, AFAIK these are standard flourescent lamps fitted with an oversleeve so as to retain heat.
When first turned on they will be too cold to give an effective light.
The fact that they give a good light when warmed up is no help to someone wanting light as soon as they open the door.
I believe that these lamps are intended for street lighting etc in cold climates or for continual lighting of freezers, not for lighting "on demand"

I would consider the LED tubes refered to above, I think these are a bit of a con trick for office lighting, but perhaps worth it for a freezer as they light instantly and are not affected by extreme cold.
 16 April 2015 01:02 PM
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RalphW

Posts: 11
Joined: 12 February 2015

I installed 20 x 5ft LED tubes in a friends cold store. Although the stated lowest operating temperature was -20 deg C and the actual freezer temp is -26 degree they are still working fine after 2 years. An added benefit is the reduction in heat output as this saves on the cooling!

Ralph
 16 April 2015 07:34 PM
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HarryJMacdonald

Posts: 545
Joined: 15 May 2002

I've installed an LED tube equivalent. Very happy with it, but a good idea to try a few first and take before and after lux level readings
If the fluor has a switch start then you just change the tube and fit their special starter (which may be just a fuse or a link!) If your flour is starterless you need to rewire to take the ballast out of the circuit..
When considering the economics, remember that running a light costs about £1 per watt per year. For lights in a cold room it will be 3 times this figure as someone needs to pay for getting the heat produced out of the cold room as well.
 16 April 2015 10:16 PM
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stateit

Posts: 2694
Joined: 15 April 2005

I've just fitted 24w 1200mm LED replacement tubes as opposed to the 15W that OMS indicates.

I guess it depends on the LED density.

I have a 'go-to' guy who's been importing LED lights for some years now. PM me if you want his details. I know he supplies LED lighting to people like CEF and the like.

-------------------------
S George
http://www.sg-electrical.com
 17 April 2015 03:29 PM
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aligarjon

Posts: 4053
Joined: 09 September 2005

If you use a door switch, when they go in and shut the door, which i pressume they should ? the lights will go out.

Gary

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Specialised Subject. The Bleedin Obvious. John Cleese
 12 September 2015 01:36 PM
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broadgage

Posts: 3170
Joined: 07 August 2007

Please be aware that this thread is over 5 years old and that technology has moved on since the earlier posts.

I do however stand by my earlier remarks that LED tubes intended to replace fluorescent lamps are well worth consideration. For GENERAL lighting I remain a little doubtful, but for FREEZER lighting they are often a good choice. They start instantly at full output and both the light output and the working life are IMPROVED at very low temperatures.
Low temperature fluorescent lamps are fine if lit continually but are no good for intermittent use, they take ages to reach the correct internal temperature, and give a very poor light until warmed up.
IET » Wiring and the regulations » Freezer room and fluorescent lights

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