Advice with design plans for greenhouse

[Patrick]

Hello AP community,

I'm still very new/green to this but I'm hooked and trying to plan the next system that will hopefully allow me to grow a large amount of my families consumption. I'm pretty methodical at whatever I'm doing which is why I'm planning this out well in advance of even completing cycling of my first system.

I'm in the process of buying a new (different) house on 10 acres mainly because our house in the suburbs doesn't have enough sunlight to have a garden except in the front yard. We've found the house we like, already have buyers for ours and are close to closing the deal on the new one. I went out yesterday with 3 of my closest friends so they could look at what I'm wanting their help doing and was pleasantly surprised to hear its doable and not near as much as I thought it would be. I want to incorporate some pretty unique methods of gardening there. An earth contact AP greenhouse as well as 1 acres worth of hugelkultur raised beds.

The house sits on the highest piece of the property and has a perfect southern side with no obstruction of light even on the winter solstice. This will also be perfect for the solar array. But as far as the AP goes I'm thinking of using the entire depth of the house (36') and excavating down 6 1/2' even with the basement floor and out 6' to 7' which would give me about 250' square footprint. I'm thinking about just knocking part of the foundation wall out underneath the window well for a door. One of my friends has a glass company and already has enough for a single pane structure put aside but I was thinking about buying enough for a dual pane if he cant salvage enough in the next 2 months.

I've also located a guy close by with a warehouse full of ibc totes who said if I bought 4 of the 330 gallon ones for $400 he'd let me have any of the several punctured ones he has for free (no waste for cutting extra beds). So I could have 4 x 250 gallon tanks (after cut) evenly spaced down the 36' wall which would give me room to walk around them. I'm thinking about compartmentalizing them so I can have 2 tilapia and something else in the others.

The solar thats going in will be in a parallel not grid tied, so I plan on doubling up everything water and air pump wise, for redundancy. Each of the 4 tanks will all have their own dc powered pumps and ac grid powered pumps.

This is my plan so far, I'd like to hear your opinions, thoughts and/or concerns. I also need your help figuring out the best plans for grow beds/vertical pvc layouts to maximize the space available.

Thanks
Pat

[TCLynx]

You can post pictures directly into your posts by using the IMG button (it's the one right next to the link button on top of the post box.)

Like this

[TCLynx]

What are your ground temperatures and what is the proposed fish?

See earth contact and geothermal are great if the temperature you are going for is matched with your ground temperatures.  But if you are hoping for the ground contact to help while raising tilapia but your average ground temp is like 58 F, well then it won't be so much help because you will still need additional heat or to use heat pumps to elevate the temperature since tilapia won't thrive till the water temp is above 70.  (Tilapia survive between 55-70 F but they are not eating or growing much)  So choose a fish that will still be eating at your ground temperature and you will likely be much better off. 

The ground is a huge thermal mass, not an insulator.  If you are trying to maintain a temperature above the ground temperature and you have a lot of ground contact, that huge thermal mass will be wicking the heat away to warm itself and since the ground is huge you might not want to pay that much in heating to bring it up to your desired temperature so it would be better if your desired temperature was in line with what the earth in your location has to offer.

[Patrick]

Thanks for the replies TCLynx, it's funny after I posted this yesterday I stumbled upon someone else in KC with the same idea from four years ago on a different site and you were there too. I still haven't decided what type of fish. I was thinking about tilapia in the 2 eastern tanks and catfish in the others but am open to suggestions. I'm looking for a good balance, I definitely don't want to have to use submersible heating. The 2 heating elements for the house are on the other side of the wall from the east side which are a LP and a wood burning backup furnace. So I'm thinking with this plan the green house would basically be inside and if I needed to I could just leave the door open and the ambient from the wood furnace would heat that half pretty well. I was considering running some passive phase change elements (copper pipe) under the tanks if it wasn't enough. Similar to how we cool servers with advanced heat sinks.

[Patrick]

Now that you mention it, I guess it wouldn't be a big deal at all to put 2 of those tanks against the wall on the other side in the basement. That would insure significantly warmer temps in the winter.

[TCLynx]

But recall what I said about the ground being a huge thermal mass, are you really going to heat up the earth to keep a couple tanks of fish warm enough?

Research the ground temperatures and your proposed fish before you ground couple.  If your desired temperatures are warmer than the average ground temperature at your location, then you would be better off insulating and using water tanks or other thermal mass inside the insulated envelope.

[Patrick]

TC I thought I'd try something, I uploaded a pic of a solar water heater I started building last night. I think when I'm done with it it'll have 4 reflective sides like a solar cooker. I'll start posting numbers when it's operational to see if it might be theasable to have a 1-200 gallon or more tank just for the heat sink powered by 1 solar panel with no battery. Then it will only run when it's hot and not circulate cold into the system at night.

[TCLynx]

Cool, start a thread on your heater so you can post the pictures and results with it.