Design your greenhouse! Lean-away IS BETTER than lean-to! This will surprise you!

 I got the basic info on the web, found the most suitable area on my site and started building. My glass was free and huge! and between that constraint and the site shape I ended up making something quite different!  In using it, I have found out that a considerable amount of direct sunlight in summer comes from NORTH of  the east west line!
So a typical south facing lean to greenhouse will fail to collect this light! 
Perhaps you can learn from my successes and mistakes and the tools I found online while trying to explain what went right.
This explains what I did, why I did it and why it works so well.
Information has come through during this project  that makes a compelling case for lean away greenhouses.

Step 1: Why is it lean away?

The only thing I bought for this greenhouse was the silicone to put the glass in frames and the screws to hold the wood together.  Everything else, I had on site and was determined to use.   The glass was 4 ft by 6 ft, 5 sheets and my wood meant that I could  do 2 large frames and one small one.  The glass was so heavy that I was afraid if I leaned the big pieces, it could fall over as i worked with it.   It had the unusual shape so that it lined up with the fence at the side.  Once I put it on blocks to keep it off the soil, it was pretty high at the front.    Lean away was the only solution.!

Comments

[killerjackalope]

As an odd side note - buying cheap showers and their doors can be a great source of large glass sheets that are well toughened, on a project I'm building they've come in very handy, had some sitting in storage for no apparent reason...

[gaiatechnician]

I used some sort of slider shower door on this one too!
Just added the pictures last night. They got me stalled and tempted me into making sliding doors because they have rollers. Couldn't do it with my material but had hinges so swing door it is! Hard to attach them (not much spare metal on the things to drill into) and latch them but I think it is figured out.
Added pics of watering in clay pots too.
Brian

[zacker]

I bet the shower door glass that you cant see through, the like, textured glass would be excellent because of the way it would refract the lighting coming in. great idea!

[gaiatechnician]

I actually didn't want to use the shower door because it is a bit large but it works fine. You are probably right about the texture too.

[killerjackalope]

Ah we reframed the glass for our purposes, since it looked sorta shower doorish...

[killerjackalope]

Hmm might well do, I know that old school watery looking glass is great for refracting, since all the light gets through - used to have it through out the house and had to replace a window with normal for a bit and there was a big drop in light getting "around" the room...

[gaiatechnician]

I made a video based on what I learned.  It has some of the same information but is arranged much differently and you might get a different perspective if you watch it.  (In the video I goofed and put in the wrong latitude for Victoria, but other than that I am pleased with it).
The thing that really surprised me is just how far north and south the sunrise and sunset times and places move through the seasons. (When you plot them all together on a site plan) It is DRAMATIC!  Video is at

[ortsa]

In your search for more more more sun you may want to consider that in the height of summer when sun is coming from the north in the mornings and evenings, that its the time when greenhouse temperatures get very high and shading is necessary to prevent damage with a traditional lean to, so you are just giving yourself more work with no benefit. Also in the winter when the angle of the sun is lower you are reducing the light because of the angle of the glass and positioning of glazing bars.

[gaiatechnician]

Nope, the higher front gets more sun in winter. There is absolutely nothing wrong with getting north eastern light in the morning when the greenhouse is cool anyway. Light is what plants live on. Also, the angles work better to bounce the light away around midday in summer than a lean to.

[gaiatechnician]

I did a preliminary experiment that suggests that LESS THAN 12 hours per day of the sunlight in summer comes from SOUTH of the east west line. Could anyone verify that? If it is correct, it means that the lean away greenhouse is more useful than I thought.
Thanks Brian

[redrok]

Easily.
Lets move to the equator.
Then the sun is north of the East-West line, the equator, all the time for 6 months out of the year.
Ok, that's an extreme example but it illustrates the seasonal declination motion.
The further away from the equator you go the less extreme.
So, the answer is yes it's possible depending on location and time of the year.

redrok

[gaiatechnician]

Hi, Redrok, (Duane) have you any suggestions for controlling the "clock speed" for my "dripper tracker". I need something that goes something like 20 inches at a constant speed, It could be some sort of worm gear. It doesn't need to be strong. Just powerful enough to hold up a 1.4 inch diameter plastic tube.
The best one (potentially most accurate) is called the liquid piston tracker but it is just a concept so far. Interesting that you commented today, because I was listening to talkshoe this morning. (The energy dude interviewed you)
Another thing where your input would be valuable is solar powered DC bubble pumps. I am using a 120 volt bubble pump to irrigate my "pallet garden" and honestly it is working really well. It would be so much neater if it was 12 volt solar. But I cannot find a 12 volt bubble pump on the market.
Brian

[gaiatechnician]

Hi, Redrok, I was kind of talking to people in northern temperate regions at the time! I used to go on the CR4 engineering forum where about one in 10 people are open minded and helpful and the rest were a mob shouting people down. Anyway, I asked that question there and the mob appeared first and lynched me! Then someone checked and anyway, it has been verified for northern temperate regions. It is always less than 12 hours in the southern part of the sky for me at 48 degrees north. In high summer, it is about 10.5 hours for me in the southern part of the sky. So for a while, I had people rudely telling me to get a compass. I would have guessed it was exactly 12 or more than 12 hours in the southern part in high summer. It was a big surprise to be less than 11 (At my latitude). Guess that makes your solar trackers more important, doesn't it?

[gaiatechnician]

found a good demo of the sun's path in the sky. It is video at http://higheredbcs.wiley.com/legacy/college/strahler/0471417416/animations/ch02/animation3.htm

[gaiatechnician]

Just a note that Usbport on the Cr4 engineering forum came up good yet again!
He has used the "starry night" program to confirm that the sun spends less than 12 hours per day in the south sector of the sky. Who would have thought! Here is most of his post from Cr4
"On this date, at 53 degrees North (for Nottingham), the Sun rises at 4:48 AM at a point of 50 degrees azimuth. It reaches the due East position, 90 deg azimuth, at 8:23 AM. It transits the meridian at a civil time of 1:08 PM (the time on your wall clock).

It then reaches the due West point (270 deg azimuth) at 5:52 PM, and then sets at an azimuth point of 310 degrees at 9:25 PM. Total daylight hours is 16 hours, 37 minutes. The Sun spends 10 hours and 37 minutes in the 'South' part of the sky, between 90 and 270 degrees azimuth. It spends 3 hours and 33 minutes in the Northeast part of the sky and 3 hours and 35 minutes in the Northwest part of the sky."
He also included diagrams from the program.
Thanks Usbport!!! You made the difference.
Brian

[fozzy13]

Introduction:
          "..why I did it and why it works good."
Should be:
          "..why I did it and why it works well."

I'm sorry to be a grammar snob...
Greenhouses are awesome, and it's great that you were able to build one, especially with free glass!  Great job : )

[gaiatechnician]

No, its fine. I am from an old country and I was trying to write American to "blend in". I will correct it now.

[zacker]

Well, today here in America, if you want to write American then you did just fine...lol American (English) is a dying art now. Especially on the Internet. I know because My With has her Masters Degree in english and creative writing and works as a full time professional proof reader so i have to hear it all the time. Do you know what emailing her is like? or worse... texting her? lol,lol,lol...

Anw way, dont worry about a thing. Write how you want to, we'll figure it out or die trying.

I do like your greenhouse, We want to build a green house as well but the town we live in would never let us make one like this because they have really strict building codes. if I wanted to even build a ground level deck, I'd need all these permits and inspections.. when all is said and done, it would cost me a couple hundred dollars just to be able to build it, never mind the actuall building cost...lol I could throw up a 16x12 deck in a few hours once the concrete footings have cured.

[rimar2000]

I agree with Jessy.

[jessyratfink]

Lots of good tips - it turned out great. :D