T8 LED

I thought that I have posted about this efficient T8-LED bulbs here. I was going to update, but I can't find the original thread. Maybe I forgot to post it for some reason. But here is the link to the detailed conversion of shop light etc (from 2 years ago).

I've been using at least 50 bulbs of Sunritek T8-LED bulbs to grow carnivorous plants and orchids for 2 years. I used more bulbs for the household fixtures, but they are not used for a long hours like grow light. Some of them are in high humidity grow tents, but none of them has failed, and I'm pretty happy with this. Now it is not the top efficiency. But compared to T8-LED bulbs or LED shop light commonly available from Lowes etc, it is still at least 20% more efficient.

Anyway, I didn't have any more fixtures/shoplights to convert, so I made a frame with left-over lumber. It's nothing fancy, but I thought that some of you might get some ideas from it.

Here is the link to my Orchid Borealis blog post about this. Instead of adding this info to the original blog post, I made a separate entry.

 

Clusty, I have one or two unused T5HO fixtures left, so I probably will convert them eventually, but I haven't looked into T5HO-LED bulbs recently. There are some, but when I looked at them about a year ago, the efficiency was slightly lower than T8 LEDs and they were quite expensive. Also they were not ballast-bypass type, so you get additional penalty in efficiency (ballast can lose up to 10% or so electricity as heat). Natch Greyes uses T5HO-LEDs for his highland carnivorous plant tent. I talked to him about it during his conversion, but I haven't talked to him for a while. I think he is pretty happy about it: link to his setup.

Sunritek is a bit older, so it pulls around 147lm/W (156lm/W for 10W version, which I used in this fixture). It is better than commonly available ones. This ballast-free one from HomeDepot is 106lm/W. This Philips (requires working ballast) is 123.5lm/W, but if we include the loss due to the ballast (let's say 10%), the system wide efficiency becomes 111.15lm/W (=123.5 * 0.9).

Samsung H-Series Gen. 3 is even better than Sunritek in terms of efficiency. It is around 180lm/W. The newer Samsung Q-series is about 10% better efficiency, so it achieves almost 200lm/W. With regard to price, Sunritek has high shipping cost, so it requires that you place a relatively large order (e.g. local group buy). If you place a large order, it is slightly (but not significantly) cheaper than Samsung (per light output). Samsung linear strips are easy to DIY, but I would say that T8-LED is even easier. So there are advantages and disadvantages of each option.

There are other newer T8-LED bulbs with higher efficiency (similar to Samsung linear strips). One company (TES light) wasn't too easy to communicate (Sunritek is very easy). I contacted My Lumens Technology (link to their web site) about 193lm/W T8-LED. They seem to be very easy to communicate. But I haven't bought from them, and I don't know if they are willing to deal with individuals (Sunritek seems to be ok, but some other companies want to deal with retailers).

 

One more thing I learned recently is that for 2' and 4' Samsung linear module, F-series (e.g. LT-FB22B) is probably a better deal than H-series. They use same diodes (LM561C), but they have 1.5x more diodes. The price is only slightly more expensive. You can run F-series at a lower current than the nominal current, and you can gain a higher efficiency. If you run F-series at the nominal current, aluminum C-channel I use might not be enough as the heatsink.

 

Hmm, Digi-key seems to have minimum order of 1 for 4' ($26.51) here: https://www.digikey.com/product-det...=usd&WT.z_cid=ref_octopart_dkc_buynow&site=us

For 2' ($14.48), it is also available at min. order of 1: https://www.digikey.com/product-det...=usd&WT.z_cid=ref_octopart_dkc_buynow&site=us

I only checked for 4000K and 3500K.

 

That's good they make ballast free version. The T5HO-LED bulb I knew from last year was Luxul E-lux: E-Lux Series LED Tubes | Luxul Technology Inc It is 122.37lm/W, but this one requires ballast, so after you consider the ballast loss, it is probably similar to Hyperikon.

 

Hyperikon, which Clusty found, is a ballast-bypass type, but Luxul E-series (message #8) is direct replacement with compatible ballast.

Also there are a couple others which requires T5HO ballast (i.e. no modification):
LED Fluorescent Tube Replacements - F54T5/HO | 1000Bulbs.com
T5HO ballasts are more homogeneous than T8's case, where there are many different types of ballasts. But with any of these, I think you should check the ballast compatibility. With T8 direct replacement type, I did manage to make the ballast in a cheap shop light explode. Not too scary, it's just a small poof, but it could surprise some people.

Sunpark has the highest total output around 4000lm from 28W. I think it probably uses around 31W in reality (due to ballast loss), so it is around 127.3lm/W (for 4000K). I'm assuming the ballast loss to be 10%.
T5 HO & T5 HE Ballast Compatible LED Tubes – Sunpark Electronics Corp.

Philips has one, too, 3500lm with 24W, beam angle 160 for $16.99

Philips 24W 46" 4000K T5 LED Bulb, Works with T5HO Ballasts | 24T5 LED/48-4000 IF | Bulbs.com

At the system level (after considering ballast loss), 131.2lm/W. So it is a little higher efficacy. But I have measured Philips InstaFit T8 (with a high quality ballast), and my measurement doesn't quite match with their spec. My measurement was much lower than the other bulbs with lower lumen output. I can't measure the total output, so this could be just due to the difference in the beam pattern.

Clusty, with T8 or T5HO LED bulbs, a lot of them have narrower beam patterns (fluorescent tubes emit 360 degree). So even if the total output is lower, you can get similar photon density at the plant level. Generally T5HO fixtures have a better reflector (than T8). So the loss is smaller than with T8. But I think that 3500-4000lm T5HO-LED (with narrower beam spread, some of them has a wide beam spread) should be quite similar to fluorescent (4000-5000lm). Also, for the fluorescent, the lumen listed is initial output, and they decays a little bit over time.

 

I have forgotten about the details of reflector efficiency, but here is a thread where Tyrone mentioned that a good florescent reflector can deliver about 75 % of light (msg #24 & #29).
What type of T5 bulbs do you use? - Page 3 - Slippertalk Orchid Forum- The best slipper orchid forum for paph, phrag and other lady slipper orchid discussion!
So 1x54W T5HO is about 3750 lm (=5000 * 0.75).