High efficiency table tennis lighting

[AC/DCdude17]

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Your conclusion of needing twenty 4' lamps is consistent with JM's previous
post in which was concluded that 19 32W T8s would be needed, but 7 T8 HO 86w
lamps would do the same job.

I went back and read his post and he didn't make a specific mention of physical
dimension. You're aware that HO T8 lamps are 8 feet long, correct?

If you can just install them over the game table, you can just hang a bunch of
shop light like fixtures.

JM calculated the number of lamps needed based on direct comparision between
source outputs. Realistically, you have to consider luminaire efficiency. If
the reflectors on the new setup is just as efficient as reflectors on your
current setup, side by side comparision of lamp output can work, but the white
reflector on the typical fluorescent fixture isn't all that efficient. I'd
guestimate it to be 60-80%.

 

[markp]

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I went back and read his post and he didn't make a specific mention of physical
dimension. You're aware that HO T8 lamps are 8 feet long, correct?

Yes, I had concluded that - they're over 2.5 times the wattage, however in
this case it might help matters that they are longer.

If you can just install them over the game table, you can just hang a bunch of
shop light like fixtures.

That's the idea.

JM calculated the number of lamps needed based on direct comparision between
source outputs. Realistically, you have to consider luminaire efficiency. If
the reflectors on the new setup is just as efficient as reflectors on your
current setup, side by side comparision of lamp output can work, but the white
reflector on the typical fluorescent fixture isn't all that efficient. I'd
guestimate it to be 60-80%.

Good point, I presume it's a rule of thumb and will probably need tweaking
anyway!

Mark.

 

[Sammy]

If the reflectors on the new setup is just as efficient as reflectors on

your
current setup, side by side comparision of lamp output can work, but the

white reflector on the typical fluorescent fixture isn't all that efficient.
I'd guestimate it to be 60-80%.

And 500 watt quartz fixtures are the most over used glare bombs there are.
They do not have efficient reflectors.
Most of the light that is produced by the fixture is lamp. That makes it
pretty darn efficient! Lumens per watt, lamp life, overheating and fire
hazards are another story.
You have to think more of the package the light is operating from to get a
real idea of what is right for this job!

Good point, I presume it's a rule of thumb and will probably need tweaking

anyway!

This rule of thumb would work great if this were someones basement or
garage!
I thought you wanted an arena that was fitting for international
competition?

Obviously, my earlier post of the use of indirect fixtures was not taken
seriously.

Take a look at this:

Room

50 X 50
18 Foot Ceiling
15 Foot Mounting Height
Reflectance 80 50 20
Table reflectance 10%

2 -Tables - Regulation 5' x 9 ' - 2.5' AFF spaced 20' OC

4 rows of 5 - 3 lamp - F54T5HO indirect luminaires spaced 10' OC

Overall averarage FC 68 max to min 2.8:1

Playing Zone average FC 75 max to min 1.7:1

Tables average FC 85 max to min 1.2:1

This looks like a pretty efficient system to me.
Oh, the ceiling is the reflector. The playing zone ceiling has an average of
216 FC at 3.1:1 max to min

The cost of the system is probably more than you want to bear at this
juncture. Maybe you could get a Forest Gump Grant

A reasonable budget figure for the material alone would be around $10,000.00
for the system.

Regards,
Sammy

 

[markp]

This rule of thumb would work great if this were someones basement or
garage!
I thought you wanted an arena that was fitting for international
competition?

Yes, of course it will need tweaking and adjusting with a lightmeter to the
exact requirements. Unless you are saying you can be 100% accurate with a
paper design....

Obviously, my earlier post of the use of indirect fixtures was not taken
seriously.

Reason is very staright forward, it is in a gymnasium sized room! the
ceiling is some 30 feet high. Obviously you made some assumptions.....

Mark.

 

[Sammy]

Yes, of course it will need tweaking and adjusting with a lightmeter to the
exact requirements. Unless you are saying you can be 100% accurate with a
paper design....

You can never be 100% accurate with a paper (or computer) design. You can
however be pretty darn close.
Variables such as actual surface reflectance, obstructions as well as
ambient temperatures play a part in the actual illumination achieved. The
system designer must also be very knowledgeable in the light fixture's
performance to be properly specified.

Reason is very staright forward, it is in a gymnasium sized room! the
ceiling is some 30 feet high. Obviously you made some assumptions.....

No assumption was made. I was simply stating what an indirect system could
do in an 18 foot application.
In my previous post I stated:

"Not knowing the exact proportions of the TT stadium, an exact
recommendation
would be difficult."

Had you responded to your actual conditions, a high performance system could
have been recommended for you.
Irregardless of the system that you choose to employ, a design application
lay out of the arena would offer your best solution for making the correct
decision. There are many more items to consider when properly designing a
lighting system than just knowing the lumen output of the lamp and its
efficacy.

I agree that indirect lighting in a 30 foot gym impractical in most cases
but it has been done with success. It is however much more expensive than
conventional high-bay systems.

Sammy

 

[markp]

No assumption was made. I was simply stating what an indirect system could
do in an 18 foot application.
In my previous post I stated:

"Not knowing the exact proportions of the TT stadium, an exact
recommendation
would be difficult."

Actually you made the assumption that your earlier post was not taken
seriously! Quote:

"Obviously, my earlier post of the use of indirect fixtures was not
taken seriously."

It certainly was taken seriously, and thanks for it, but the ceiling is too
high to be practicable in this case. I apologise for not giving feedback on
that.

Mark.