It’s been covered in Solarig the last 10 years. The inside layer of that failed where it contacts the frame. It’s been by far the best covering I’ve had. The first two were normal 6 mil 4 year greenhouse single layer poly. Those lost inflation after 2-3 years due to hail or just stress points that opened up holes.
With shipping Palring costs about 50% more but lasts three times as long. If one further factors in one covering vs three coverings the Palring is less. I’m figuring $400 labor to get the new covering installed.
Yes, two layers with an inflation blower pumping air in between them 24/7/365. That increases the insulation value of the covering. And even more importantly keeps the poly from flapping in the wind. Thus, increasing the lifespan of the poly. My blower is 60 cfm and 1/15 hp.
Hopefully the trees don’t get sunburned too bad with their sudden move from diffused to direct sun! I really do think you’ve got one of the best looking greenhouses I’ve seen. Major envy here.
Yes that is an issue. It’s going to be hotter and much harder on the plants today than when it was when covered. Most people would probably think the opposite.
I also got to see full sunlight on some of my greenhouse plants today. I am raising the roof for one polycarbonate section to facilitate better air flow +automation.
It’s 108 in the greenhouse right now. Well, probably not but that’s what the sensor is reading. But it’s in the sun. Outside it’s about 96. So the sensor is heating up about 10F in the sun.
I think they have. But it comes on 4-6ft wide sheets. That takes all the advantage out of it for me. The mounting is much more expensive. And seams mean leaks. Leaks are like lower R value.
I want it 40 feet wide with the top layer woven and an inch thick. In the interesting trivia department, I put up an outer layer of plastic, then made some plastic strips and put a second layer up on the inside of my greenhouse. No need for a blower with it set up to maintain a few inches between layers. I used self-tapping screws to attach to the ribs on the inside. My old greenhouse was not fancy, but I managed some tricks with it.
I’d think that someone would soon offer a Chinese style greenhouse. That is, one with automatic, heavy-duty insulation that cranks down at night and uncovers in the morning. Maybe someone already does and I haven’t seen it. An R10 insulation at night changes the equation. Even triple wall polycarbonate is less than R3.
About 10 hours of hard work and the new poly is in place. I like it.! Its more light than the old. The light is about 50% direct and 50% diffuse. The Solaring was nearly 100% diffuse. It would be good as a single layer. The Palring is hopefully better for double layer.
I checked the light in the interior of my greenhouse at near solar noon today. Outside was near 11,000 foot candles. Inside it was 6500 foot candles, 55% of outside.
Then I took some remnants of the Palring 175 that was just installed. There was 71 % transmission thru one layer and about 55% thru two layers. My old covering was at best 50% inside the GH when I checked it over the years.
The manufacturers usually rate most clear coverings near 80%. 70% is probably closer to the truth.
What kind of light meter are you using? The only one I’ve got is the sensor on my phone, which can be revealed using an app like “GPS Status.” I have no idea what the accuracy is for that, though.
Using that, my dusty, algae-filled twin wall 8mm polycarbonate seems to be about 62% of full sun outside. I suspect it was quite a bit higher than 70% when it was new and clean.
It measures in both LUX and foot candles. I use it in Ft candles since that’s what I remember from school. 10K ft candles being full sun. 11K today.
I just measured at about 3 hours before sunset. It’s about 80K lux outside with zero clouds. And about 50K inside. Both measured in the horizontal plane. So that’s about 62% inside vs outside. The same as yours.
I don’t think that will limit whole canopy photosynthesis or brix. Broadleaves like peach can’t use full sun. And the more diffused light inside a greenhouse is a plus not a negative for whole canopy photosynthesis.
Ah, I did mine trying to point the face of the phone directly at the sun (i.e., maximum reading I could get from that location), I’ll try horizonal next time.
