edmolina

Eddie's Greenhouse Build

66 posts in this topic

Hello all, just wanted to share some progress on the greenhouse build. I decided to go with a modified SCHS, although as Ravnis pointed out, my climate may not be ideat for it. The footprint will be 8'x16' and I had some guys excavate a trench 2' deep (as much as soil conditions allow without major expense) around the permiter and at 2' O.C. along the long axis. We installed rigid foam insulation and a grid of 4" drain pipe to serve as the heat exchanger. Here is a picture during the work:

post-2252-0-26980600-1400427264_thumb.jp

 

Also, here is a layout schematic, in which I tried to use as much materials on hand as resonable. The NW and NE walls will be insulated to a height of 4', and I'm thinking of going with Solexx as the glazing material. I decided to keep the fish in the garage and run everything in the greenhouse with fish water on a separate loop.

post-2252-0-25510000-1400427542_thumb.pn

 

Thoughts, suggestions?

Caca and jvnicholson like this

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wow that is tight, I should never complain about a lack of room again (but I probably will :D )

 

Any plans for a little corner or shelf for seed raising?

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Yahoo,

 

I have a 4' shelf for starting plants in the layout above the water tanks. Once I set it up, I'll see where I can squeeze a second shelf - maybe stack them.

 

As far as lack of room, one of the most common comments from coworkers is that I have to move to a more rural area with a few acres. I will say that combining a small urban lot, keeping enough lawn area for the kids, and carving out every little available corner while trying to make the whole thing aesthetically pleasing has presented some fun challenges.

 

On a different note, I'm happy to report that the espaliered apple trees that I put in last June are doing quite well and look very healthy. Thanks again for reminding me of doing an espalier.

ande likes this

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I envy your ability to dig down like that.  I have the very nastiest swamp clay only about 6 inches down, and it's solid black.

 

I really like how you have separated your growing system from your fish system.  This is a GREAT idea!  Now you can use aquaponic water in the hydroponic beds and the wicking beds and not worry about the wicking beds loosing oxygen and attracting anaerobic bacteria.  I do something similar with a hybrid wicking bed system that has its own sump tank, but not like this where the hydroponic and dirt beds are plumbed together.  That is really neat. Now you could potentially use fertilizer supplements without worrying about doing harm to your fish.

 

What kind of filtration are you using on your fish tank?  Also I'm assuming that you'll pump some water into this system from the fish tank as needed, or if you want to do water changes, etc...

 

Craig

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Thanks Craig. It will be nice to be able to add any supplements without concern for impact to fish. The plan is a combination of fish water and rain water, once I have my cachment setup. Periodically, I'll replinish with fish water, and use rain water to replenish the fish tanks.

 

As far as filtration, I have a RFF to Particulate/Bio-filter to duckweed/sedimentation (although the duckweed mostly died off - still working to figure that one out) tank to MBBR/sump.

 

Regarding soil conditions, the area is known for its clay - having been the source for most of the brick for NYC buildings in the early 20th century. We have decent topsoil, but after about 6" to a foot, it is clay with some rock, except for my garden areas where I've build up the soil over several years. Funny that you would envy this, because when excavating, I kept telling the workers to make sure that they didn't mix any of that poor soil with my black gold. :thumbsu:

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It is funny that you mentioned the apples, the conversation we had and a few tweaks to my tree growing technique have given me the confidence to have a go at some apples and pears myself this year.

 

Disappointingly, I have made the same sort of mistakes that I tried to stop you from making. It must be deeply ingrained in us from birth or something.

 

I didn't buy from a specialist nursery.

the trees are arriving in June, not August, like they should be here.

the varieties are not heritage ones with a variety of flavours.

And for a fleeting moment I considered not growing them as an espalier.

 

There is a business in Tasmania that has had about 90 old apple varieties for sale this year, I should have purchased from them.

 

Regarding the G/house, I think it will work, it may not get you right through the winter in some years but stable temps and lengthening the growing seasons will make a huge difference. I had winter veg seedlings growing in a cool spot and avoided three heatwaves that would have killed them, then transplanted them into the garden. The result is I have been picking broccoli, peas, beans and winter greens for over a month, most of my friends are still waiting for the first pick. Perhaps a bit of home DIY bubble wrap double glazing on the walls that dont get sun will stop some heat leakage and boost your winter temps?

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Good luck with the apples Yahoo. Maybe things will work out as they have for me thusfar. I'll post pictures soon, b/c two out of three are starting to look like a decent espalier (one was stunted last year b/c one of my cucumber trellis' wound up blocking too much sun - lesson learned). I think the effort with putting in a good amount of compost, healthy soil and promix (which has Mycorrhizae) really made a difference.

 

As far as the greenhouse, the glazing will be Solexx, which has a better R and U value than any other glazing material that I have researched (although not sure what you'd get out of a double layer of plastic with blower). Also, I plan to insulate the NW and NE walls with foam insulation. I'll post progress pictures soon.

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Some of the websites that talk about subterranean heating and cooling systems (shcs) are saying this wont work efficiently without a good level of humidity. That the phase change from liquid to vapour captures the energy above ground and drawing that vapour through the pipes changes it back to a liquid and releases the heat to be stored.

 

And further to that, plants drawing water up and transpiring that water through their leaves (as a vapour) is the principal way this phase change and energy capture happens.

 

This is a lot trickier than I first thought.

 

I know as a farmer there is a rule of thumb, that if the humidity in the late afternoon is above 50% then the temperature overnight will not drop below the dew point, because there is so much stored energy in the water vapour that is released as the temperature drops.

 

if it is below 50% all the vapour changes to water , there is no energy left to hold the temperature up, at that point the temperature begins to plummet, and we get a frost. Unless a weather front comes through and saves us.

 

Does that mean there needs to be a reasonable level of transpiring foliage in the greenhouse to drive this? or will an atomiser or  tiny mister do the same job?

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Another Question

 

Will a humidity that is too high in winter cause condensation on the inside of the roof losing heat to the outside on a cold sunny day in preference to the underground pipes?

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My experience with an aquaponic system in the greenhouse will run 78% to 98%.  The readings are from a cheap digital weather monitor, so take with a grain of salt.   The readings were consistent, and I had major condensation when the outside temps were colder.   Had to make sure electrical connections were safe from drips

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Thanks for the link yahoo - very interesting reading indeed. I am hopefull that the UG thermal mass will regulate temp and humdity, and we'll see with time. The sump in my system is for the circulating wicking beds/hydroton/DWC and will not collect water from the ground. I don't expect that there will be excessive water trapped beyond the soil's saturation point, but this is only a feeling based on anecdotal evidence.

 

Ravins, as you say, with so much water circulating through the system, I don't expect that lack of humidity will be an issue. My indoor system has been in the 60%-80% range (based on a cheap term/hygrometer that I picked up).

 

I plan to buy a higher quality device that will measure current/max/min temp and humidity and I will track and post results as I go. Hopefully, this experiment serves as a usefull source for others.

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Hello folks - been a little busy with work, but thought I drop to share some progress shots.

Hired labor hard at work:

post-2252-0-07950300-1402711662_thumb.jp
Greenhouse update:

post-2252-0-16051500-1402711751_thumb.jp

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Hi Eddie,

 

Excellent progress......particularly when you look back at the photos of the drainage earthworks.

 

Have you considered using a short pipe to vent the stale (but warm) air from your house into the greenhouse?

 

Gary

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Thanks Gary.

 

I made some more progress this past weekend, and have completed most of the framing, and I expect to be up and running by the end of the month. Also, I designed an add-on that I'm pretty excited about; the greenhouse structure is adjacent to my deck, and I plan to build a 1' wide wicking bed attached to the exterior of the greenhouse, on the deck. This will also be piped into the circulating system (shut off when the freeze starts) and it will give me the ability to capture rain runoff from half the structure to replenish the system. Additionaly, I plant to use the exterior bed for grapes on a two wire trellis, which will shade the greenhouse from the hot afternoon sun during the summer.

 

As far as piping from the house, I had not considered that. Will have to think about it and see if I can come up with something that works and is aesthetically pleasing.

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What you really need is one of these to fall off the back of a truck, at midnight, right in front of your house :) while no one is looking!

 

post-3002-0-07158400-1403078558_thumb.jp

 

its a heat exchanger, it will swap the stale air (and moisture) out while keeping the heat in. They are a dynamite bit of gear.

 

it is quite a simple thing, outside air is pulled through the inlet (bottom left), up through the exchanger into the chamber top right and forced out the outlet into the house.

at the same time stale air is pulled into the inlet (top left) down through the exchanger core to the chamber bottom right (loosing its heat across the barrier to the fresh air in the process) and out.

TheDictator likes this

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That's pretty nifty Yahoo. I'm hoping that the SCHS serves this function in the greenhouse; we'll see how well it works...

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HAH.  If we ever get below 50% humidity, it probably happens 10 days out of the year :)  

 

This business of disconnecting my fish from plants has made be re-think the way I built my original aquaponics system.  I just bought two IBC tanks...the bigger kind, like 300 or 325 something gallons (not the 275).  I'm thinking of designing two separate tanks with 100% dedicated filtration, potentially with a separate sump tank not even connected to the hydroponic growing system, which is halfway across the yard.

 

BTW, you made a combination moving bed bio reactor and sump tank?  Is your pump inside this tank that pushes water back to the fish tank?  If I'm picturing that correctly, then you would use gravity flow to move the filter media around sufficiently, right?

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Yes, it is a combination sump/MBBR. The pump is in there and originally I had an air pump to move the media around. Now I just have part of the water pumped water dumping back into the MBBR and that stirs up the media sufficiently while saving on energy.

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It can be a trap just looking at relative humidity because the amount of water that the air can hold is dependent on temperature. The best indicator of how much water is in the air is the dew point.

 

In a greenhouse, a heat exchanger lets you dump humidity without opening a window and letting the cold in. If you warm the outside air as it is coming in the relative humidity will end up much lower than it was outside. At times the air in the greenhouse can be both hot and almost saturated from the plants transpiring.

 

it can be a pain to try and extend the growing season only to have fungus devastate everything.

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I think I might copy this design.  Would it work in a 55 gallon barrel? Would you mind describing where you ran the gravity fed drain?  I'm assuming at the that the outlet of the pipe is somewhere near the bottom of the barrel, and facing up so that the water flow would circulate the filter media...

 

Since the filter media floats, your submersible pump would be at the bottom, or your pump inlet would be at the bottom so that it won't suck up any filter media.

 

Is this close?

 

 

Yes, it is a combination sump/MBBR. The pump is in there and originally I had an air pump to move the media around. Now I just have part of the water pumped water dumping back into the MBBR and that stirs up the media sufficiently while saving on energy.

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Yahoo, fungus is quite a nasty thing that has caused me a bit of heartache in the past. I'm curious to see how the SCHS handles humidity and will track and post results.

 

Craig, My setup is a 55 Gal barrel with the pump at the bottom of the barrel. The pump inlet is small enough that no media can fit through if the water gets too low, and I also have a mesh, cone filter on the pump - not that it's really needed, but provides better flow when the water level drops by keeping media from jamming the pump inlet. Feed into the pump is gravity fed, but not strong enough to do much in terms of stirring up the media, but your idea of setting it low, facing up seems very promising and something that I will incorporate in my next modification (I'm using my current sump/MBBR as my greenhouse sump, and plan to replace the pump with larger piping).

 

My setup now has the pump discharge part of the flow back into the sump and that is the primary means of stirring things up.  

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Greetings all, just posting an update:

Structure is just about complete, need to add the two center panels with bottom vents, as well as, back window vent.
post-2252-0-41197500-1404734648_thumb.jp

Need to add glazing and install door.
post-2252-0-05963500-1404734676_thumb.jp

Wicking bed almost complete, hydroton tank in place, just need to fill and complete plumbing

post-2252-0-68232000-1404734724_thumb.jp

early likes this

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