Lean-away greenhouse has unexpected advantages! Maybe a really useful thing!

Thousands of google images show lean to greenhouses. I didn't see them before building mine. The "perfect place" in my back garden is near a neighbour fence that runs east west. I got 5 huge sheets of 6 ft high free glass and I was determined to use them. the fence is already about 6 ft high and by the time I put the glass up on blocks to prevent termites and wood rot, it was 8 ft high. I couldn't lean it against the fence because when framed in it was too heavy for me to lean on my own. so I sloped the roof back towards the fence and put the gutter on the back. Anyway, it leans back instead of forward. And guess what? It catches way more summer light than if I made a typical lean to. for starters the roof is at a super angle to let morning and evening light through. Lets about 50% more of the light through than a lean to in the evening! Because the light strikes it at a better angle. Also the front glass reflects this light so that at about 8 pm significant amounts of light hit the north east corner of the thing! Bouncing off the front glass on the inside! Here is a video of the light effect. Lean-away greenhouse cool light bounces!
Anyway, I started a thread about it on the CH4 engineering site and a guy there showed me a graph that applies to the light in my greenhouse. After making mine, I finally saw the google images. Amazing that there is no lean-away greenhouses among them!
Thanks Brian

are you planting in the soil under it, or in pots? How are you watereing yours.

I have a soaker hose in my greenhouse and I'm planting in the soil itself rather than in pots..it is small and gets crowded but it works out well for me. I add mulch and ammendments when they are avail.

Hi Brenda, it is first time greenhouse for me. I have planted mostly in the soil. It is a kinda lean to so I have shelves with pots on the backwall, a small raised bed there and another one at the front. so far i water by hand but later I am going to get a "windofarm" hydroponic plant thing going too. I am pretty surprised at how fast it gets plants moving. It is really only a month old and already I planted out 3 ft tall runner beans that I started in it . There are 5 tomato plants (all different types) and a couple of peppers and some basil. All sorts of things are being sown from seed in it and transplanted out. I have the planters with soil because hopefully that means less watering than pots.

Brenda Groth wrote:are you planting in the soil under it, or in pots? How are you watereing yours.
I have a soaker hose in my greenhouse and I'm planting in the soil itself rather than in pots..it is small and gets crowded but it works out well for me. I add mulch and ammendments when they are avail.

http://www.sollumis.com/ Nice tool to show sunlight direction on any day of the year at any location. I think there is 3 rays per hour in their diagrams.

Surprised that there is just above zero interest in this. In summer in the northern hemisphere, how much of the sun's path is in the southern half of the sky? answers 1. 12 hours exactly 2. More than 12 hours 3. Less than 12 hours
And your answer is?
Anyway, I know the answer and you can find it at http://www.instructables.com/id/Design-your-greenhouse-Lean-away-Better-than-l/
Brian

Hey Brian what are the dimensions of your greenhouse?

Brian, I went and looked at your instructables page, but there's no picture there of the whole greenhouse, so I can't really figure out what it ended up looking like. Does lean-away just mean it's freestanding? If not, is it on the south side of the building it's leaning away from? Again a picture with a wider view would be helpful.
Thanks,
Gani

It is against a fence. Normally when someone builds a greenhouse against a fence, it is lean to. (The glass slopes up to the top of the fence). (and you can check google images of lean to greenhouses. They are ALL like that!.) But mine has the glass rising up from the fence to a higher line. BUT even though it is quite a simple change it is very different. It is on the south side of the fence but unlike a lean to, it catches sunlight from the north side of the fence easily. I have several diagrams and drawings on the instructable to explain that. Note that in summer in the northern hemisphere between the tropics and the arctic circle,less than 12 hours of sunlight per day comes from the southern part of the sky That means that the rest of the sunlight comes from the north east and north west. My greenhouse uses that light well while a normal lean to uses it really badly. And it may be low to the horizon but it is still light. About 6 hours of direct sunlight at my latitude every day comes from the northern sector right now! That is not to be sneezed at. So, why do people put summer use lean to greenhouses on the south of houses? The house blocks all the incoming light from the north! Come on folks, do we all have to use the Homer Simpson method?
I have had people in other forums getting mad at me and calling me an idiot for suggesting that the sun rises in the north east (in norther summer). (Get up early tomorrow and check before writing a smart assed answer). People got really mad when I told them that my model shows less than 12 hours of daily sunlight comes from the south in a northern summer. And don't get mad. A guy used an astronomy program and confirmed it. (For Nottingham England in Late june, it was 10.5 hours in the southern half of the sky and 7 HOURS in the northern half!) There is a diagram of the site, with rain barrel to the left, gutters behind, etc that might be helpful to you. It is on first or second page. Some pages have several pictures. (Just how instructables to things) and sometimes if you click on a picture, different things are explained.

gani et se wrote:Brian, I went and looked at your instructables page, but there's no picture there of the whole greenhouse, so I can't really figure out what it ended up looking like. Does lean-away just mean it's freestanding? If not, is it on the south side of the building it's leaning away from? Again a picture with a wider view would be helpful.
Thanks,
Gani

Hi Brian, I watched your video on Youtube, and have to say this is QUITE REMARKABLE!

And am also glad that someone besides me can see this potential. It was wonderful to see the proof by the person who sent you the graph.

I live in the US/Central Appalachian region in Southwest Virginia, and YES the sun rises in the Northeast here.

This model of Lean-away Greenhouse can help many folks who otherwise might not have enough sun exposure.

So glad you took the time to research this for yourself and to share this with the world. Regardless of what others say. Many helpful ideas come along and some people just can't wrap their minds around it.


Keep on keepin' on!

http://higheredbcs.wiley.com/legacy/college/strahler/0471417416/animations/ch02/animation3.htm is really good for explaining how the sun's path changes during the year.
And the more I look at things like that, the more I think that putting a lean to greenhouse on the south side of a building is daft!
Also, the art of illusion people do have a decent "sun engine" right now. I have not used it myself but apparently, you can just draw up your lot or scene or garden or greenhouse in the program, and add the sun at different times of the year and see how it shines and where the shadows go. (Art of illusion is animation and modelling software and it is the only one that i ever got to work.)

Brian White wrote: Also, the art of illusion people do have a decent "sun engine" right now. I have not used it myself but apparently, you can just draw up your lot or scene or garden or greenhouse in the program, and add the sun at different times of the year and see how it shines and where the shadows go.

Google Sketchup can also render shadows based on geographical location. I was able to obtain high resolution LIDAR data files including our property, and convert them to the Sketchup format. Now I'll be able to model various potential layouts and see how the shadows fall on any given day of the year. In particular, I hope to position sunscald prone fruit trees so that they are shaded in late winter/early spring, but get full exposure in summer.

Is that included in the free version of sketchup? Sketchup is unavailable to me currently because I use linux. If it isn't in the free version, the pro version is $495 and it is called Trimble sketchup now. (Google sold it). Thanks
Brian

Victor Johanson wrote:

Brian White wrote: Also, the art of illusion people do have a decent "sun engine" right now. I have not used it myself but apparently, you can just draw up your lot or scene or garden or greenhouse in the program, and add the sun at different times of the year and see how it shines and where the shadows go.

Google Sketchup can also render shadows based on geographical location. I was able to obtain high resolution LIDAR data files including our property, and convert them to the Sketchup format. Now I'll be able to model various potential layouts and see how the shadows fall on any given day of the year. In particular, I hope to position sunscald prone fruit trees so that they are shaded in late winter/early spring, but get full exposure in summer.

Yes, it is included in the free version. Some Linux users have reported success running Sketchup under Wine. There are tutorials on YouTube; here are a couple:

http://www.youtube.com/watch?v=mSsuBaKYjV8
http://www.youtube.com/watch?v=yLK1zuxR9KY

Victor Johanson wrote:

Brian White wrote: Also, the art of illusion people do have a decent "sun engine" right now. I have not used it myself but apparently, you can just draw up your lot or scene or garden or greenhouse in the program, and add the sun at different times of the year and see how it shines and where the shadows go.

Google Sketchup can also render shadows based on geographical location. I was able to obtain high resolution LIDAR data files including our property, and convert them to the Sketchup format. Now I'll be able to model various potential layouts and see how the shadows fall on any given day of the year. In particular, I hope to position sunscald prone fruit trees so that they are shaded in late winter/early spring, but get full exposure in summer.

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Victor, what is LIDAR and how does a person go about obtaining the LIDAR data files for their property? Can a person find this information about property that they may interested in purchasing without yet "owning' the land?

Thanks.
Max

Max Hubbard wrote:Victor, what is LIDAR and how does a person go about obtaining the LIDAR data files for their property? Can a person find this information about property that they may interested in purchasing without yet "owning' the land?

Thanks.
Max

LIDAR is an acronym for Light Detection And Ranging. ( http://en.wikipedia.org/wiki/LIDAR ) Basically, an aircraft flies over the target land and scans it with lasers. The position of the aircraft is precisely triangulated so the data can be corrected for flight turbulence, and digital elevation model data is collected and formatted. There are free datasets available to the public at http://ned.usgs.gov/, and others can be found online. There are some online viewers, too ( http://lidar.cr.usgs.gov/LIDAR_Viewer/viewer.php ). The data for Alaska is very limited; however, our land fell within a corridor which was surveyed as part of a potential gas pipeline route, so I was able to obtain data which is accurate to within inches. I'm still trying to figure out how to incorporate the cloud point data for the tree cover, but I did manage to get the land contours successfully imported into Sketchup using a trial version of Global Mapper. Now I just need to learn enough Sketchup to do what I want!

I put the wrong latitude in for victoria. It is just over 48 degrees but that is the only major mistake
Brian