A few more years of working with irrigation have lead me to this conclusion:
Compression tees w/hose fitting plus tape adapter
Don’t use these compression tees to assemble your system. Not that there is anything wrong with them, but they take a lot more labor to install than the barbed fittings. The header tubing has to be cut to lengths, and each tee has to be forced onto a length on each side, which takes time and hand strength. Then you have to have a second fitting to join the drip tape to the tees.
An easier way
Much better, in my opinion, are the barbed fittings. You just punch a hole in the header tubing and push the barb into it. The drip tape attaches right to the other end of the fitting and it’s done. No cutting and very little forcing. Very fast. Cheaper, too.
If you need to change the layout the following year, just buy a new roll of header tubing (100′ = about $15) and punch new holes. It’s a lot better than having to pull all the tees off, cut new lengths, and push the tees back on. If there are only a few changes, you can put goof plugs in the old holes and punch new ones.
So, anyone want to buy a bunch of tees?
Tom's Gardens 
Comments on: "Irrigation Update" (7)
good one. not going to try it. Just a little too sore to go out in the garden but like your set up.. thank you,,,,,,,,,,,,,,, don ,,,,,,,,,,,,,,
I’m hoping to build my own greenhouse and I stumbled upon your wonderful site. Noticed you haven’t posted anything recently but hoping you’re still around. I’m not happy with the drip irrigation in our yard and several other things, and hoping you are available for advice/encouraging.
I’m definitely still around and happy to help if I can, though the only drip irrigation I’m really familiar with is for row crops in a garden. Shoot me any questions you may have and I’ll do my best.
Thanks Tom. I’m currently constructing a shopping list for the greenhouse. Have you considered adding misting or any watering capabilities to yours? Also, what did you use for flooring? Hard to tell what you did in the pictures. The irrigation is going to be later : )
Since my greenhouse is attached to my basement, for watering I use a self-coiling hose that attaches to a faucet just inside the door. For the fairly short amount of time I have plants in there, the hose has been all I need. For flooring, all I have is three boards running down the center. The area under the shelves is just bare dirt plus whatever plants/weeds happen to come up. Nothing fancy.
Hello, I’ve just today began to explore your blog and see it’s been awhile since you’ve posted. I just want to say thank you for all the inspiration here and I love your way of posting, very helpful! I hope you are well and still gardening.
Hi, Jill. Thanks for checking in here. Yes, I am still gardening, but posting—not so much.😃
I’m not growing for market anymore and the things I am still doing feel a little too commonplace to interest anyone else.