The Ultimate CBUS LV Globe?

I have often read on this forums and others that IRC globes are the best to use with respect to brightness and efficiency in the application of general home downlights.

Does anyone have preferences amoungst Osram globes? Are there variants of globes that are better than others to any small degree?

Ideally, does anyone have specific model numbers of preferable Osram globes.

Effectively I am looking to combine an Atco Possum with an Osram IRC globe however I am often quoted other part numbers including decostar and EXN etc etc -- just want to be sure what to ask from our electrician.

Many thanks!

 

A PDF of the Osram catalogue page for IRC is attached to this post

Generally... 35W IRC = 50W normal (Titan), even more compared to cheapy chinese lamps. In many projects you can get away with 20W IRC if there is heaps of lights used to create an "effect" (eg" sparkle)

The codes "EXN" etc refer to the beam angle and wattage. These ANSI codes don't really apply for the new IRC lamps, as the 35W lamps have different codes than the 50W ones.

For 50W lamps
12? = EXT = Osram SP (spot)
24? = EXZ = Osram FL (flood)
38? = EXN = Osram WFL (wide flood)
60? = FNV = Osram VWFL (very wide flood)

As a rule, 2.4m ceilings usually use 60?, whilst 38? is used on 3.0m and higher ceilings, and/or where more punch is required. Note that all lamps give the same nett output, the only difference is the amount of area that each illuminates. You really need to do a proper design or test the beam angles to know what will work best.

I hope that helps, JohnC

 

Many thanks for your input and info John.

My electrician said I should just go for the 50W IRC, given that you can simply dim them down to 80% as standard, and have the flexibility to brighten up certain areas when needed & extend globe life still further.

Any opinions? My partner like it nice n bright, there's going to be approx 25 globes in our L shaped family, kitchen meals area - combined with three pendants when required for different mood settings.

 

Only comment I'd make is that 50W IRC are harder to get than 35W.

You can dim the lamps to any level (dunno what he means by "80% as standard"). Lamp life will be fantastic when dimmed. 5% dimming will double life, so a good trick is to preset the dimmers for 95% max. Nobody will ever know, and you'll save a fortune in lamps.

For example, in my kitchen we have 4 x LVs on a dimmer. We have a low mains voltage (usually 230V), so that even when running flat out they only get about 95% voltage. Those lamps never fail (ever) - I only replace them when the silver coating expires (it's consumed in normal operation) and the lamp has a completely clear reflector which passes more light up than down into the room

 

Understood, thanks - we'll see how we go getting these globes from Melbourne or Sydney.

By 80% standard his implication is you can set the dim level to 80% all of the time (standard level), and even add a ramp to 80% level over say 0.5 sec -- similar to your suggestion, you would hardly ever be replacing globes due to being blown.

Globes may be ok, I hope we aren't going to be replacing many tranformers

 

IRC lamps

Hi Guff
If you have not seen them in action, you'd probabally not tell the 35W IRC from a 50W standard (from a light level perspective). The IRC are an excellent lamp, we put in 35W everywhere when we are doing "energy saving makeovers". I have never used the 50W as they give you even more light. I'm guessing you have a big area, but 25 lamps at 50w is 1.325kW (inc tx losses) that will chew the power and most likely blind you. If the area is 8m x10m that will deliver 15.6 watts/m2 which is a huge amount. Australian energy efficiency building codes (BASIX etc) would not let you put that much in. Using the 35w will drop it down to 10.9 w/m2 with no drop in light level. (Spend a few dollars and get a 35w IRC lamp to try.)
Also Need to be careful with the transformer loading on your dimmers, plenty of other posts on this. Suggest you get a 70w transformer and install 2 x 35 lamps on them, the electronic transformers like to be loaded up.
Regards Matthew

 

Hi Guys,

OK the Osram IRCs seem in plentiful supply for what we require (35W and 50W), our application calls for a total of eighty globes.

It is a very large house and area. The main room which is meals-kitchen-family as L-shaped room is:

(10ft ceilings)
Meals - 8 x 50W WFL + 1x Pendant
Kitchen - 6 x 50W FL (over benches) + 1x Pendant
Double width Corridor - 5 x 50W WFL + 1x Pendant
Family - 8 x 50W WFL + 1 x 50WFL + 1x Pendant

(The pendants are eight-light chandelier type.)

Not so bad for the area involved, but the globes will never be on 100% level, more likely 80-90% MAX. And most likely not all on at the same time, and most likely in combination with pendants. If we want blinding light in certain areas at certain times (may still only be 90% of full 50W capability) then it will be available.

We're fitting seperate (individual) globes + 1xAtco Possum for every downlight, using maximum 4x transformers per channel for dimming and using 2.5A dimmer units. I figure 2x2.5A are not much more expensive than 1A dimmer units.

Would welcome any comments - the important thing to note is that these, as with many houses, are only part of a lighting scheme that will use the various loops of globes to varying degrees the combination of which (in the end) will be normal lighting levels / power consumption. My thinking is why not get 50W globes if they'll last longer dimmed to 80%, they aren't more expensive and if a LOT of light is required in one area for some reason, it's available.

Cheers.

 

Hi Guff,
The only comment I can make is that 35w IRC globes are a TON brighter than you might think. My mother's house has 12 foot ceilings, so quite high, and every downlight I've installed in her house has the 35w globes installed.
Also, my workshop has 10 foot ceilings, and I have 35w IRCs installed in it as well, and they are placed a little further apart than in most installs, and they are still more than adequate. They give off more than enough light to see even the smallest detail (especially important when working on delicate and finer electronics in my workshop).
The 35w IRC globes seem just as bright as the 50w non-IRC's, plus they appear to have a much better light, at least all my family and I think so.
When you are running large numbers of downlights to cover a large area, in my experience, there isnt any point running 50w non-IRCs anymore. 35w IRC's in large numbers can easily be blinding when run at 100%.

Not saying don't use the 50 watters, just saying don't discount the 35w IRC's, as they provide more than enough "punch" in my experience.

Darpa

 

Let's look at the numbers...

50W standard = 910 lumens

35W IRC = 900 lumens

50W IRC = 1250 lumens

So, to get the same light you'd dim the 50W IRC to about 70 to 75% light output. Due to the way incandescent (halogen) lamps work, efficiency drops significantly as voltage is reduced....

75% ouput is achieved at about 90% voltage, and voltage and power consumption are fairly proportional.

So, assuming that C-Bus dimmers are linear (ie: % = voltage) you would set you dimmer at 90% to get the same light from a 50W IRC as you would from a 35W IRC or 50W standard lamp.

In energy terms this is a bad decision - you lose 25% of the light for only a 10% saving in power. However, the undervoltage has a good effect on lamp life, which is approximately doubled at 95% and quadrupled at 90% power.

The other downside of dimming a 50W IRC to the same level as as 35W IRC is the colour of the light, which will be more "yellowish".

See attached file which shows the relationship between Power, Life, Output (flux) when voltage is changed. I am not sure of the source or accuracy of this chart, so use it for general guidence only.

Don't let all that put you off the idea... just be aware of the consequences

Cheers, JohnC

 

Great input, thanks.

Colour, power and adequate light all weight into globe choice and so I'll be sure to test out the options and post back our experiences (may take some time but shall do). The perfect thing is that globes aren't permanent and we can test things out before committing to the final choices.

There's one area under the stairs where we are putting a globe only 1m or so above the floor, and so I expect that we'll utilise a 20W VWFL to obtain the same lighting area and brightness as WFL globes at a greater height.

It seems so far that Atco Possum plus Osram IRC are (currently) good choices for CBUS systems (best practice??). What I now want to ensure, is for our real life install (light spacing [some quite sparse], height [a few 22ft above floors] etc etc - there's a few variables!) and personal preferences on lighting levels etc that either 35W or 50W are the choice for us. I know that if I don't make absolutely sure, my wife will string me up for getting talked out of brighter globes that don't quite produce "enough" blinding light because of our personal preference and lighting plan .

Thanks again, further comments welcomed!