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Topic Title: Light fittings
Topic Summary: Lighting at 45 Degress
Created On: 10 August 2012 09:11 AM
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 10 August 2012 09:11 AM
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Avatar for Jobbo.
Jobbo

Posts: 912
Joined: 08 July 2010

Morning All

I'm currently looking at a project that has a room heated at 45 degrees for a gym class. The wiring and accessories have been designed accordingly, but I'm having trouble trying to spec lights, as most manufacturers cannot provide me with enough information

The room will have heating and ventilation services, so condensation should not be a problem. MK have informed me that their standard products i.e. sockets and grid switches are suitable

What else should I consider?

Regards

Jobbo
 10 August 2012 09:40 AM
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Jaymack

Posts: 4622
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Originally posted by: Jobbo
What else should I consider?

Ask for a re-appraisal of the specification for 45°C.

Regards
 10 August 2012 09:58 AM
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ebee

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45 Degrees? Gosh I did not realise people still used Degrees F these days but it sounds about right for a Gym.

Personally would have thought about 55 or 60 would be more common though

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 10 August 2012 10:08 AM
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OMS

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45C is a very high temperature particularly if the activity is physical.

do you mean that the supply air condition is 45C - o you have radiant heating at 45C.

If it's actually 45C comfort temperature (or environmental temperature0 then, for the lighting, you may need to consider the impact of temperature on lamp output.

more generally, ypou have very little headroom left in the system for temperature increase under load, so particu;lar attention to cable sizing (and MCB derating ?) might be needed.

For T5 lamps expect to see about 10% decrease in light output at 45C - it may be more as within the luminaire (assuming they are enclosed to mitigate lamp breakage etc) th etemperature will be even higher as the luminaire cannot cool effectively.

Your emergency lighting batteries will also have a much shortened life.

I'd check that design temperature first - it will save you loads of grief if it should actually be 21C

Regards

OMS

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Failure is always an option
 10 August 2012 12:37 PM
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Jobbo

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Ok ive had a look into exactly what the class is being used for:

Bikram Yoga is a system of yoga that Bikram Choudhury synthesized from traditional hatha yoga techniques and popularized beginning in the early 1970s. Bikram's classes run exactly 90 minutes and consist of a set series of 26 postures and 2 breathing exercises. Bikram Yoga is ideally practiced in a room heated to 105°F (≈ 40.6°C) with a humidity of 40%

The ceilings are going to be of a MF construction

Due to the humidity, all final circuits are to be 30mA protected
All cables has been designed for an ambient temp of 45°C, but will be positioned outside of the heated area
Light switches are to be located outside of the class room
The socket outlets were initally going to be logic plus, but following further investigation of the heating services, they will now be masterseal

The client originally wanted to spec 1200x600 high frequency fittings with open louvres, as these were installed in another of their buildings

Regards

Jobbo
 10 August 2012 12:51 PM
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OMS

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LoL - I just love the irony of the tree huggers burning fantastic levels of resources and requiring a significant increase in the carbon burden of thier environment - I guess the don't move very fast or very often at that temperature for sure.

To get a constant 40% RH is going to need both dehumidification and humidification systems as well - energy hungry so you need to allow a good bit more supply capacity for sure. That said, 40% RH isn't a problem with ordinary accessories and outlets - so i thing you are over egging things with master seal - 40% RH occurs quite normally in heated rooms in cooler periods outdoors.

To be authentic, won't you need candles for lighting - made from organic beeswax and natural hemp I would have thought -

Derate the lamp output by about 10% and used a reasonable IP rating from the room side - if only to contain broken lamps.

And fit double knock AFD - silly buggers are bound to be burning jos sticks -

And Ohmmmmmm - and relax - and lets try and forget about the polar bears -

regards

OMS

-------------------------
Failure is always an option
 10 August 2012 01:08 PM
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Jobbo

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OMS

See this is why I want to know more about HVAC

Cheers

Jobbo
 10 August 2012 01:24 PM
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micjamesq

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Why don't they just build a big polytunnel for them to sweat in. Anyways, that is beside the point. Your post reminded me about a clip I saw on you tube a while ago about this:

Alex Jones on The One Show doing yoga 24th September 2010

I thought this "celebrity" fad would have been over by now.

Oh hummmmmmmm - now you know what it is!!!

Regards

PS - I don't know how I managed upon this clip - I think it was on one of those totally random YouTube voyages that you go on from time to time.

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E & OE
 10 August 2012 01:52 PM
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OMS

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Originally posted by: Jobbo

OMS

See this is why I want to know more about HVAC

Cheers

Jobbo


Well, if you have cold outdoor air at 100% saturation - typical UK condition in winter and you heat it up to put into the room it's ability to absorb water increases with temperature therefore the relative humidity will go down - you need to know if all the loonies in the room are breathing out enough moisture to make up the difference - probably not, so you need to add water vapour - and the most hygenic way of doing that is with a steam generator (you don't want a legionella outbreak on your hands)

so we've added water and increased the temp and then the class ends and presumably the temperature goes down - at that point the air cannot contain all of the water and as the temp drops you get to a dew point and all that air suddenly dumps itself as liquid water.

So you now need to move it through a process (usually cooling) that "rinses" the water out of the air - de humidification in effect.

In summer, you may also need to de humidify as the incoming air is warmer but may also be saturated - so now you are probably into cooling (for de hum), then reheating and humidifying to the supply temp

all of which takes lots of energy - and i suspect you'll also be moving lots of air about to keep 30 or 40 people supplied with enough fresh air and to remove odours

It's not difficult, but make sure the mechanical designer gives you all the loads - they could well be quite heavy in terms of electrical demand.

and track down a copy of David Chaddertons book (don't worry about which edition) and start reading - you'll soon know if a HVAC HNC/HND is for you

regards

OMS

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Failure is always an option
 10 August 2012 01:56 PM
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Jobbo

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"and track down a copy of David Chaddertons book (don't worry about which edition) and start reading - you'll soon know if a HVAC HNC/HND is for you"

I'll take a look. See i'm being drawn in already

Jobbo
 10 August 2012 02:09 PM
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OMS

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It's the dark side mate - once you step over that boundary and join the mechanical brigade (or pipe stranglers) you can't ever go back - when you start saying things like Q = MCp DeltaT in they same way you curently say V= IR then you know it's too late and you suddenly have to start calling yourself a Building Services Engineer - which most people don't even know exits - and they think BSE is something mad cows have

next time your at a party, try it out - someones bound to ask what you do - tell them your a building services engineer - and then be prepared to explain that you do all the pipes lights and wires in a building except the ones the s**t goes down - and you might even end up doing those depending on where you work - avoid doing public health at all costs

Seriously, do it if it interests you, do it because you want the knowledge or do it for a laugh. Don't do it to get a badge or because someone else thinks it's a good idea - a HNC/HND in a subject you have no background experience in isn't an easy ride, you'll need a bit of enthusiasm and a sense of humour to get you through.

Best regards

OMS

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Failure is always an option
 10 August 2012 05:44 PM
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mawry

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 10 August 2012 06:19 PM
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rocknroll

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Originally posted by: Jobbo

"and track down a copy of David Chaddertons book (don't worry about which edition) and start reading - you'll soon know if a HVAC HNC/HND is for you"

I'll take a look. See i'm being drawn in already

Jobbo


A few years ago I needed to purchase this particular book, not for what you are seeking, it was a module for professional registration but is more than adequate for your persuit, I have had no need for it the last few years and in my future 5 year assignment in the E Devon/Dorset area in a few months time building services is not something that is on the agenda, therefore before I leave in a few minutes for the train if you PM your personal/business address you are more than welcome to have it to save some cost and I will arrange for it to be posted to you at no cost to yourself, it is the fifth edition so it is well up to date.

My pleasure,

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 10 August 2012 06:51 PM
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peteTLM

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Top marks to that man!

-------------------------
----------------------------------------
Lack of planning on your part doesn't make it an emergency on mine....

Every man has to know his limitations- Dirty Harry
 10 August 2012 08:09 PM
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Jobbo

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RnR

Thankyou very much, that's very kind of you. Details have been PM'ed

I owe you one

Cheers

Jobbo
 13 August 2012 01:50 PM
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rocknroll

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Originally posted by: Jobbo

RnR

Thankyou very much, that's very kind of you. Details have been PM'ed

I owe you one

Cheers

Jobbo


Not a problem, I had to come back early yesterday morning and left it with the other half to post with her business post today, it was posted a short while ago.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 13 August 2012 01:54 PM
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Avatar for Jobbo.
Jobbo

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RnR

Thanks a lot

Regards

Jobbo
 13 August 2012 02:05 PM
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OMS

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Good on you, Rock -

Keep sharing the love !!


OMS

-------------------------
Failure is always an option
 13 August 2012 02:21 PM
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Avatar for OMS.
OMS

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Originally posted by: Jobbo

RnR

Thanks a lot

Regards

Jobbo


We'll give it say a month, and then start asking questions about HVAC - you won't be thanking him then !!

Good luck -

OMS

-------------------------
Failure is always an option
 13 August 2012 02:29 PM
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rocknroll

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Originally posted by: OMS

Originally posted by: Jobbo

RnR

Thanks a lot

Regards

Jobbo


We'll give it say a month, and then start asking questions about HVAC - you won't be thanking him then !!

Good luck -

OMS


LOL That section may cause a few headaches.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
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