Skip to main content

T8 LED fixture

I covered how to convert shop light fixtures to use efficient T8-LED in a previous post.  The efficiency of T8-LED bulbs are widely variable, and the efficiency of commonly available T8-LED bulbs has been slowly improving.  However, the bulbs from Lowes, Home Depot, or Walmart are way behind, and they are still at least 20% less efficient than Sunritek bulbs which are 2 years old.  Now there are T8-LED bulbs with the efficiency higher than Sunritek.  But you do need to source these directly from China, and you probably won't be able to get those locally for a couple more years.

I haven't had any failure with Sunritek bulbs (>50 bulbs), and I have been extremely happy with the results.  I have converted all of the shop lights and I needed additional fixtures to use Sunritek T8 LED bulbs.  I decided to use left-over lumbers to make a fixture cheaply.  I made the frame with 1x4 and L-shaped hardwood trim and painted it.  Mine will be used in a grow tent, so it is humid, but it doesn't get splashed with water.  So I used whatever latex paint I had.  If it were more exposed to water, I would use UGL Drylok latex-base masonary waterproofer, which I have been using to paint plywood water catch trays and shelves inside the grow tent.  I haven't used it long enough, but Drylok seems to last better than Elastomeric roof paint, which lasted about 3 years.  It is for masonary adn not recommended for wood, but it seems to adhere well to wood.

I have considered to use the "tomb-stone" style method of attaching T8 LED bulbs.  But I found that I can get the connector (see the next photo) with the wire attached cheaper from eBay.  You can search for "T8 lamp socket", and they are about $4 for 4 sockets (including shipping).

There are two types of T8-LED bulbs: single-ended and double-ended.  T8 has 2 pins at one end and another set of 2 pins at the other end.  With double ended T8-LED, the two pins of one-end is internally connected.  So AC live goes to one-end (you can use either pin), and AC neutral goes to the other end.  With single-ended T8 LED bulbs, 2 pins in one-end are not connected to anything, and they are used to attach the bulb physically to the fixture.  The two pins of the business end (the other side) are connected to AC; one pin is for live and the other pin is for neutral.  I prefer single-ended to simplify the wiring, so all of my Sunritek bulbs are single-ended (you can order them as doubled-ended if you prefer).  So I just need one socket per bulb.

The socket came with 30cm (1') of wire.  To connect these sockets to the AC plug, I used screw-type wire nuts.  Since we are dealing with 120VAC main, I used a shallow electrical junction box (something like this: $1.40 from Lowes) and a plastic cover.

I also attached screw eye rings on the top side to hang the fixture.

To attach the bulbs to the frame, I used T8 lamp holder from eBay (search something like "T8 u clip lamp holder", about $6 for 20, including shipping).

It is simple, and it can be assembled quickly.  It is also light weight, and low profile (so it can be used in the case where the distance between shelves is short).  One additional advantage over modified shop light is that I can increase the number of bulbs for a given width. I think my fixture is about the width of 2 shop lights, and I can use 6 bulbs instead of 4.


Comments

  1. When using these LED lights how do they do at providing intensity at a distance? Do you find that you need to keep the lights as close to the lights as you would with a fluorescent, or do you find that the LED lights can get you more intensity and a further distance? One thing I have really liked about the CAB LED lights is that they can push light a long way so they can be back away from the plants a fair bit and still work and I was wondering if these kind of LED lights have some of the same effect?

    ReplyDelete
    Replies
    1. I use these T8-LED bulbs similar to T8, so I try to place them very close to the orchids. So the top of the leaves is from near touching distance to 45cm (1.5ft), but most of them are within 15-30cm (6"-12"). With COB (especially inside of reflective grow tents), it is easier to work with plants due to the distance (4' from the floor, so about 3' of distance). There are pros and cons of point source light (HID, COB-LED etc) vs light with wide emission surface (fluorescent light, T8-LED, linear module LEDs etc). Point source light can give more working space above the plants, but you get more even coverage with the wide emitter. Also, the lower leaves get illuminated better with the wide emitter.

      Delete
    2. You answered my question perfectly, thanks!

      Delete
  2. LED lights use less energy, save money and is environmentally friendly

    ReplyDelete

Post a Comment

Popular posts from this blog

Kenmore dishwasher leaking diverter motor

Fun in Northern Kenai Peninsula

Samsung Linear LED module H-series Gen. 3