Final doubt on Lumens

From: Jose Gengler (jose.gengler@usa.net)
Date: Tue Apr 21 1998 - 18:03:02 PDT


Date: Wed, 22 Apr 1998 01:03:02 +0000
From: "Jose Gengler" <jose.gengler@usa.net>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg1337$foo@default>
Subject: Final doubt on Lumens

Hi!

I've got lots of information on ilumination right now. I know for
instance that for plants that are suposed to be under "direct
sunshine in reality", should recieve about (or at least) 10000
Lumens. I also know that the quentity of Lumens received by the plant
are a function of distance. Finaly, I also know that my terrarium
will be 40 cm high.

Since I have been writeing and asking about this in the list, I have
also found out that there is no significative difference in Lumens
output between a 220V and 110V fluorescent tube or bulb, if they
have the same potency in Watts.

Barry Mayer-Rice's FAQ recommends the use of 4 bulbs 34W each (Energy
Saving). These bulbs give 3000 Lumens each, which would add up to a
total of 12000 Lumens. I also have got advices to install 6 bulbs, in
which case that would add up to 18000 Lumens.

Now I have two choices:

Chice one: in my country the most I can get are Energy
Saving fluorescent bulbs of 26W each (1500 Lumens each) which means
that adding up the total of 6 bulbs (the maximum I can install on top
of my terrarium), that would be 9000 Lumens.

Choice two: I would be able to install 3 standard 40W tubes (the
maximum on top of the terrarium), with thir ballasts placed
elsewhere. If each tube gives 3000 Lumens, then I also get a total of
9000 Lumens, but I am not sure if in Lumens a 34W bulb would be
equivalent to a 40W tube, since tubes come without information about
lumens.

Some people wrote to me, who are using 1200 Lumens bulbs, but they
didn't tell HOW MANY BULBS are they using. Same thing for tubes. Lots
of people wrote to me advicing the use of 40W tubes. But they didn't
tell HOW MANY TUBES do they use. For 1200 Lumens, in theory I would
have to use 4 tubes, if I want 1200 Lumens.

Various persons asured that tubes are better since light distribution
will be more even.

Please help me chose, since I will now proceed to make the final
instalation. I understand I have bothered with this subject, but I
just can't meet the exact advices of the recomended settings in the
FAQ.

Thanks for your help,

()()()()()
()* || () Jose Gengler
()= []=()
() || () jose.gengler@usa.net
()()()()()



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