My budget was around 500$ and i ended up spending ~70% more , things that didnt cost anything were the labor , the bricks , most of the budget was spent on : cement , wood and polycarbonate
The temperatures in the winter are nothing like the bensoninstitute said , without any internal heating , at -15C outside , there are -2C inside , i do have a small stove but rarely use it cause i live in a small city 12km from where the walipini is built The biggest problem is the humidity (98%), cause the ground water is very high up , i was planing of having grass on the ground but that's not an option anymore , i'll have to put at least 10cm of gravel
I have to open a window every day for at least 15 minutes to prevent any mold and unfortunately the paint on the walls is chipping of , i guess its because of the humidity
At least now i know this is a cold greenhouse and it's not worth going through all the trouble of keeping high temperatures , out of all the citrus trees i have in there (a few hundred) only a handful of them died and i'm pretty sure it was because of the humidity and not the cold plus the cats love it in there
if you mean that i'm north of Italy then yes , i'm north of a citrus growing region
It's just a hobby really , i started being interested in plants very recently (only a few years ago)
i like to have as many green plants in my house as possible and the extra that i couldn't fit in i brought in the walipini
And yes all of them are from seed so i'm not expecting most of them to bear fruit , 50% of them are grapefruit trees so i dont want to graft them with lemon or orange trees ( cause i dont know where to buy a fruiting grapefruit tree to use as grafting material)
but this year i'm definitely gonna diversify cause even 60% of just citrus trees in the greenhouse is to much
i'll try to grow fig trees from cuttings , and i love ornamental tree and shrubs so i'll give that a try too
Well I didn't consider Italy at all. I saw snow in your pics and kinda figured you was north of the citrus region.. Lately our southern regions are getting more cool weather - so the snow isn't a 'for-sure' indicator of northern regions.
If the seed produces a plant then there is a good chance (with right conditions) that a fruit can eventually grow on the plant. You may have to hand pollinate the flowers though.
Sometimes the answer is not to cross an old bridge, nor to burn it, but to build a better bridge.
Interesting, k9, I wonder which factors make your greenhouse colder than the original. One reason that comes to mind is sun angle during the year. Maybe the sun angle where you are is more slanting than the sun angle in Bolivia? If that is the case, maybe you could reconfigure your roof? I'd love to hear people with more experience with this chime in.
..."the roof is south oriented and the angle is exactly like they said it should be , the latitude (mine is 43) + 23 . and that's a 70 degree angle"
I could be wrong but I think the Benson plans call for the angle to be calculated from the vertical, whereas yours seems to be calculated from the horizontal?
Another issue is the height of the horth wall - it appears as if yours is truncated at the same heght as the front wall? If that is the case you have more light maybe, but certainly less thermal mass.
so, is it the roof angle that causes your greenhouse to stop from getting warm enough in the winter?
i always pictured zone 5 to be a little steeper, for instance the one i was considering would have needed a 60 degree angle making it almost like this ---/l---
it could also be the glaze you are using and how much dead space is in the glaze but i would think it'd more likely be the roof angle
i am very curious to find out what errors, if any you may have made when designing this greenhouse and constructing it as i was hoping to construct one in zone 5 as well
also anyone here heard of aquaponics, i always thought aquaponics would make an excellent method of cultivation in any greenhouse due to the low level of upkeep, which is what i hate most about greenhouses
other than that i think it looks decent and appreciate you postin up your experience and pics
"I could be wrong but I think the Benson plans call for the angle to be calculated from the vertical, whereas yours seems to be calculated from the horizontal?"
So what should the pitch angle be then ? Cause i really dont think any other pitch angle would make any diference; on a winter sunny day the temperature inside can go above 20 C , so the roof is 'working'
A lot of cold air comes in through the cat doors , that are half open all the time , but even then , this winter, the temperature never went bellow -0.5 C (which i'm very pleased with)
"other than that i think it looks decent"
for a ~500$ budget i think it's a heck of a lot more then decent , but hey, maybe you can do a better job
I would like to optimize the layout to reduce the size of the greenhouse. I am thinking a modified keyhole layout, where the growbeds wrap around the path. Additionally, I will be building in a mushroom fruiting/spawning area.
Could it help any to paint your north wall black to absorb more heat into the thermal mass? I would think some kind of heat especially a wood based heat would help both the humidity and the temp. Just thinking out loud.
PS. I love the design and aesthetics of what you have done with it. Some of the purmaculture building that I have seen is very attractive and some I have seen is a real hack job aesthetically. You made this look really nice.
@K9 I didn't come back and answer your question: "So what should the pitch angle be then?"
Bottom line: if your system is working then good for you, this is simply an attempt to explain the methodology I would have used so that a) I can be corrected if I am wrong and b) if I am correct then others can use it for their projects. Long post, but I hope it is useful for someone.....
The purpose is to have the glass at right angles to the sun’s rays at the time that is most useful to you - right angles ensures maximum penetration of the energy. Given that the purpose of the Walapini is to act as a greenhouse it is probable that the optimal time is in the spring and fall. Furthermore, setting the angle based on the highest angle of the sun on any given day at that time doesn’t make sense – better to optimize it for, say, 2 hours either side of that so the optimal position is hit twice. So, the angle we are trying to find is the sun angle on the day and time you nominate, for the location you desire. Note that the angle of the glass from the horizontal will be 90 degrees minus the sun angle (sun angle is the angle between the sun and the horizon)
[I think this basic process will also work for solar panels]
STEP 2: Enter the information Go to http://www.susdesign.com/sunangle/ a. Longitude and Latitude come from Step 1
b. Date (whatever date you choose for optimizing) – I chose March 1st (will also approximate to mid-October as well.)
c. Your time zone (Oradea is GMT +2)
d. Time basis - I use "solar time" so that if I enter 1200 as time it is the point where the sun is at its highest that day. You can see clock time anyway in the output section.
e. Time: I chose to enter 1000 so that there are 2 points in the day that are optimized, 2 hours each side of the highest point of the sun that day.
f. Daylight saving (yes or no)
End result of all those parameters is an angle of 29 degrees, and therefore the angle from horizontal for the glass would be 90 - 29 = 61 degrees. Note that the clock time shows 1144 vs solar time of 1000. That indicates that the sun is at its highest point in the early afternoon as you can see if you take the midpoint between sunrise and sunset. This is a user-supported site - if you make use of the data please consider a contribution
STEP 3: Check your work
Go to http://www.gaisma.com/en/dir/001-continent.html and drill down for the location you need, or the one closest to you.
Lucky us, we can find Oradea (and many others) listed for Romania. There is a lot of information there, and also explanations for all of the terms used. Information includes rainfall and temperature, but also more esoteric stuff like insolation, clearness, wind, wet days, etc, etc.
STEP 4: Implementation
Translating this optimal angle into a practical design has its issues. At a 61 degree angle the width of the Walapini is going to be constrained by the height you need to achieve the 61 degree angle. If you took the maximum height above grade as 10', then the width would be less than 6'. Obviously a lower angle allows greater width, at a sacrifice to efficiency when the sun is low.
The white paint looks good, but I second the opinion of Ray Cover, that if you paint the back wall black, you should get better heat retention. Water barrels will also even out the temperature fluctuations. You could put them under your benches. Put insulating panels over any glazing on the North, East and West walls, during winter. If you can roll an insulating blanket over the South facing glazing on cold nights you can keep the temperature more stable (yes, I know, its 12 kilometers way). Those cat doors could be letting in a lot of cold air, even if they are small and only open half way. The stairway acts as a cold sink. Make sure the door has a tight seal. Check how much draft you have along the ridge. You want some ventilation, even in Winter, but you don't want too much.
Would a vapor barrier on the floor reduce the humidity?
Perhaps a workaround to maintain greenhouse width at higher latitudes would be to use a gothic lean-to with the side wall slanted to the desired angle? It would not be particularly difficult or expensive to bend poles/pipe/conduit or fabricate wooden supports (like this) to shape.
The calculation for roof angle described for the Walipini greenhouse is quite simplistic. There are two important factors that must be balanced when chosing roof angle. The first is sun angle. The second, which is ignored in the Walipini description, is glazing area. Ignoring the second factor works fine in La Paz, which is quite close to the equator (actually in the tropics), because optimizing for sun angle does not lead to a particularly high roof angle. But the farther you get from the equator, the steeper the roof angle will get (if optimizing for the sun alone) and the larger the glazing area becomes. A larger glazing area will result in a colder greenhouse because this is where the heat loss is greatest. Incidentally a steeper roof will also increase your construction costs.
In most cases, you should not optimize for just sun, or just glazing area (i.e. a flat roof), but try to find the sweet spot between them. You may not be able to find that sweet spot with a simple calculation since it will depend on degree-days, glazing material, how much direct sunlight your site receives and probably several other considerations. What you hope to grow in your greenhouse will also factor into your decision since you are essentially trying to striking a balance between light and temperature in your greenhouse and some plants will do fine with less light and more warmth while for others it's the reverse.
also, the author expressed things in degrees C, so i may have taken in differently but still with 0C being equal to 32F thats not quite the 50-60 i would have expected
and though there may be a few things that could have been done to increase efficiency, i would certainly say that the OP did a great job with 500 dollars, certainly better than the 600 we spent on our inefficient greenhouse just days before i learned of a walipini...
Remi Gall, I would really like to hear what has become of your walpini greenhouse. Did it fall into disuse or get repurposed? Or is it still a greenhouse? If so, what adjustments have been made in the last seven years since you posted? We can learn a lot about projects by how the hold up over time and how their use changes.