Lighting for barn

[m109254]

I'm trying to get some advice on the most efficient lighting to install in a 4 bay agricultural barn - each bay is 20 by 36 feet and 15 feet to the eaves. The building is new and I want to do the best I can to install low energy fittings.

The advice I've had so far is to use 'low pressure sodium' lights in the 3 bays where the animals are and simple strip lights in the end bay which is a workshop and machinery store.

Does anyone have any comments? What exactly are low pressure sodium lights? How big a wattage do I need - they have recommended two per bay at eaves level in diagonally oposite corners? Would two stip lights be enough in the end bay? I have local lighting for working on machines etc.

Andy

 

[Spark123]

Low pressure sodiums are very orange, they are often used in street lights. A barn is a special location in BS7671 hence it is advisable to consult this regarding the installation.

 

[Lectrician]

Low pressure sodium? They are a rarety these days! Horrible YELLOW.

HIGH pressure sodium would be more suitable. This is a bright orangish light. A 150w or 250w would be suitable I would think. You want to think if you want to fit wall flood lights or low bays fro the ceiling.

Low bays give a better spread of light with less shadows, but floods are far easier to maintain for the farmer/end user.

Flourescents are best for the workshop, hung as low as practicable.

Do not go for HQI (Metal Halide), as the light is very intense. From experience, I find farmers prefer the high pressure sodium as the animals (mainly horses and cows in my experience) are happier with this light! The bright HQI's can taunt the animals.

 

[JohnD]

ordinary striploghts are dangerous in a workshop (strobe effect on rotating parts making them look stopped)

 

[Lectrician]

ordinary striploghts are dangerous in a workshop (strobe effect on rotating parts making them look stopped)

The same 50hz flicker is present in any discharge fitting, but more so in low pressure mercury (flourescent). This does not prevent them being used extensively in workshops across the country and world!

In three phase installs, with the lighting load balanced, the stroboscopic effect is cancelled out, and in single phase installations it is possible to wire a capacitor in series with a fitting, or single tube of a twin fitting to cancel out the effect also. This is very rarely done though.

The best way to reduce or remove stroboscopic effect is to use a tungstan work light at the point of movement - a spot pointing on the drill for example.

In a small workshop you are far more likely to be aware a tool is running, as you likely turned it on. You are also far more likely to be using other sences often blocked in large workshops which let you know the tool is running.

In a farm workshop, stroboscopic effect is not really an issue.

 

[ColJack]

the animals prefer the orange light because they can't see it.. to them it's more or less pitch black...

well that's what it says on many lighting sites i've seen.

 

[Steve]

I always wondered why the pillar drills at school had a lil light on them!

 

[thompsk]

I'm trying to get some advice on the most efficient lighting to install in a 4 bay agricultural barn - each bay is 20 by 36 feet and 15 feet to the eaves. The building is new and I want to do the best I can to install low energy fittings.

The advice I've had so far is to use 'low pressure sodium' lights in the 3 bays where the animals are and simple strip lights in the end bay which is a workshop and machinery store.

Does anyone have any comments? What exactly are low pressure sodium lights? How big a wattage do I need - they have recommended two per bay at eaves level in diagonally oposite corners? Would two stip lights be enough in the end bay? I have local lighting for working on machines etc.

Andy

Personally I would go for a 70W metal halide fitting, 1 in each bay would be sufficent and then if needed local task lighting in the form of fluorescent lighting.

 

[m109254]

Thanks guys I'm really grateful. Just one follow up - what would be the lowest energy option - given that we're all trying to save the planet and this is a brand new installation which will hopefully be around for a while?

 

[Lectrician]

Any discharge fitting to be honest.

A 70watt is going to give less light that a 250watt, but will be cheaper to run.

In general, remember that discharge lighting provides for light per watt that 'normal' sources of light, and this is why it is classed as 'energy efficient'. You would need MANY TENS of 100watt GLS lamps to rival a 250w SON.