General Lighting

[David - WI]

I've been struggling to get started on a commercial system for about 5 years.

I have a bunch of four-bulb standard T5 fixtures, so switching to LED is going to be a long process (cost-wise) but I'm going to order a couple of these to test with the PAR meter just in case by some freak chance they're awesome: http://www.homedepot.com/p/Commercia...3161/205331022

[Jason]

I've been struggling to get started on a commercial system for about 5 years.

I have a bunch of four-bulb standard T5 fixtures, so switching to LED is going to be a long process (cost-wise) but I'm going to order a couple of these to test with the PAR meter just in case by some freak chance they're awesome: http://www.homedepot.com/p/Commercia...3161/205331022

Those lights are awesome. I could really have used those for my storage space due the fact that they are link-able. I did not even know Home Depot carried something like that. I just wish that they did not cost 50% in Canada. Oh well, our dollar is not what it used to be. I was able to pick up 8 LED bulbs @ Home Depot for just under $8.00 each. They were the previous model of these http://www.homedepot.ca/product/led-...t-5000k/431128 . So if you just want to reuse your fixtures, that would also be an option.

Jason

[Jason]

I should have added, I am not sure how well they will work for growing plants though. I have not tried.

[David - WI]

Cool, I have T8 fixtures in the shop so I may try some of those LED's just for the energy savings. I'll check them with the meter, too... just in case.

[Prometheus7504]

Did you ever put those fixtures on the meter?

[David - WI]

They haven't arrived yet (Thursday, I think). I have tested some different brand/color T5 and T5HO bulbs but it's been awhile and there are probably others now.

We have a lot of light bulbs that will eventually have to be replaced, so I'm really trying to find a "cheap" bulb or LED that also happens to have high PAR output; not grow bulbs but hopefully some out-of-spec shoplight/bulb that puts out a lot of PAR. I guess "abmormally high" PAR/$ is what I'm after.

[David - WI]

I've been struggling to get started on a commercial system for about 5 years.

I have a bunch of four-bulb standard T5 fixtures, so switching to LED is going to be a long process (cost-wise) but I'm going to order a couple of these to test with the PAR meter just in case by some freak chance they're awesome: http://www.homedepot.com/p/Commercia...3161/205331022

OK, these are kind of cool but I need to do some more testing. The box says 3200 lumens and 35 watts; but PAR is what we're really after. Crude test results:

At 18" away from the fixture (center) they show a PAR of 40 versus a 3-bulb T8 shop light with full-spectrum bulbs at 50 PAR... but that's one 36-watt LED fixture versus three 32-watt T-8 bulbs (96 watts); so it's mildly impressive.

At 18" from the center of a four-bulb T5HO fixture I get 150 par but that's four 54-watt tubes (216 watts). The four-bulb standard T5 shows 65 PAR from four 28-watt bulbs (112 watts).

I'll put the kill-a-watt meter on all of them when I get a chance, so we can look at total watts including any ballast or other circuitry. Also, the T8, T5 and T5HO could/should probably have all new bulbs for the test... although the bulbs are only going to be "new" when you put them into service, I don't know if they all have the same hours running or not.

The LED fixture has a very opaque plastic "diffuser" that I would like to try to remove, just to see how much it impacts the PAR reading.

The LED fixture is also very narrow, so it's not going to cover as much area as the four-bulb fixtures; but the cost is about 1/2 to 1/4 what I paid for the T5 and T5HO fixtures respectively... and the power use is 1/3 to 1/6; plus the bulb life should be 10x that of either of the T5's.

The LED fixtures have a neat little plastic "link" so that you can hook the fixtures tight end-to-end or also a short (about 12") link-cord in case you want to raise or lower the fixture independently... either way you can have up to 9 fixtures with one power cord & plug.

Now, linking the two LED fixtures with the supplied cord and laying the fixtures side-by-side gives me a 16" wide x 48" long pair that reads 60 PAR at the center from 72 watts. And lightweight, at 3-pounds per fixture it wouldn't take much to support them.

[David - WI]

One screw and two little plastic pins let the diffuser slide right off the end of the fixture.

With diffuser removed the PAR meter shows 60 at 18" from the center of the fixture and it has about an 18" wide light pattern.



So, 50% more PAR useful light with the diffuser removed.

[David - WI]

A word of caution. With the diffuser off it's possible (likely?) that the metal pull chain will contact the electrical track or solder pads on the circuit board.



Maybe not a huge deal if the lights are hanging horizontally but we had them sitting on end against the wall to test the light readings and the chain on one light dangled the wrong way and smoked one light.

[Jason]

While I think we have all been thinking that LED was the way to go, it is nice to see some number put to it. It is also nice to see that the price continues to drop. So from your calculations if you used 4 units of the LED fixture to duplicate the "four-bulb T5HO fixture", you would end up with a higher PAR using the LED vs the T5HO. It would also increase the area it covered 32" wide x 48" long. or is my math incorrect?

Jason