Understanding light bulb specifications

[Alistair]

I have a Hortilux Blue 400 watt metal halide lamp. On the box it says, "Research shows that spectral energy ratios are more significant than lumens for plant growth". With that said, I'll say that the most lumens this bulb emits is 29,000. However, I'm not sure whether it puts out 29,000 lumens or 22,000 lumens. That is why I've pasted the specs for this lamp. How many lumens does this put out on average? I'd have to say that it puts out 22,000 lumens, but I don't quite understand the performance data.

Initial lumens at rated watts after 100 hours operation 29000 lm

Mean lumens at 10 hours/start 22000 lm

Rated average life at10hrs/start 12000 h

Warm up time, maximum 8 min

Correlated color temperature 6500 K

CIE chromaticity 0.310, 0.349 X, Y

Color rendering index (Ra) 90

Operating Position HOR±15º

Time to hot re-start, maximum 15 max. min

I have about 10.5 square feet of closet and if you take 29,000 and divide by 10.5 you get about 2762 lumens per square foot. On the other hand, if you take 22,000 and divide by 10.5 you get about 2,095 lumens/sq. ft. In either case you don't get the 3000 lumens/sq. ft. minimum for good growth.

Can anyone explain to me how to read the performance specs for lights?

I've used this light for vegetative growth, and it seemed to work fairly well, but because of heat issues I can only get it about 15"-18" from the tops of the plants.

I also have what I consider to be a standard metal halide lamp and I'm not sure about its performance data; I don't know how many lumens it emits. I see no difference in growth between the two lights. However, I only use one light or the other; I don't have both going at the same time.

What do you experts think about this light?

 

[Alistair]

Bump.

 

[la9]

Go here

http://bpc.oppco.org/TechArchives/Lighting/LightOutput.doc

explains it all

 

[King Bud]

However, I'm not sure whether it puts out 29,000 lumens or 22,000 lumens

Initial lumens at rated watts after 100 hours operation 29000 lm
The first 100 hours of operation, it puts out 29000 lm.

How many lumens does this put out on average?

Mean lumens at 10 hours/start 22000 lm
Afterwards, when used 10 hours at a time, it puts out 22000lumens

 

[Alistair]

la9, I don't have the proper program for opening that document. Is there another format you could use?

 

[Alistair]

I went to Lowe's today and found fixtures for T-12 bulbs. I found the T-12 bulbs to go with it, but now that I've come home and looked at the specs for the fixture I'm afraid that I need to get a ballast and a plug for it. Here are the specs for the fixture. Does this fixture need a separate ballast and a cord with a plug before I can use it? It sure looks that way. I didn't buy anything today, I was just shopping.

Two 20 watt T12
Toolless wireway access
Numerous KO's for easy installation


Utility Fluorescent Type: Strips
Energy Efficiency: T12
Length (Inches): 25.2
ENERGY STAR® Qualified: No
UL Safety Listing: Yes
CSA Safety Listing: Yes
ETL Safety Listing: No
Ballast required: Yes
Hardwired or Plug-In: Hardwired
Number of Bulbs: 2
Width (Inches): 4.8
Height (Inches): 2.3


Also, I found a 400 watt metal halide for $20.00. I already have a metal halide lamp, but I thought that I'd share the information. Plus, I saw 250 and 150 watt metal halides at low prices.

 

[Alistair]

Actually, I've been really stupid here. I went out and bought the Hortilux-Blue 400 watt metal halide several months ago without doing enough research, and according to what we preach here on this site about 3000 lumen minimum requirement for proper growth, I'd have to say that it doesn't emit enough lumens per square foot. So, either I use it anyway, or I simply use a standard metal halide that puts out enough lumens. It's a stupid idea for me to supplement my MH with fluorescents when I could simple use one standard MH bulb instead.