Greenhouse

Lakewood, CO(Zone 5a)

I've seen some posts about heated greenhouses. I wonder if the problems could be solved by a solar greenhouse. The greenhouse would have an insulated roof and walls with vertical glazing on the south side only. Thermal mass in the floor could store and release heat at night, roof overhang(s) would prevent overheating in summer. We had one like this at school, and the temp never dropped below 55, no matter what. I know that's not optimum tomato weather, but they won't freeze. Heat mats can be used to germinate seed, and other measures could be taken to increase soil temps. Here is a little sketch, please give feedback. If anyone ever needs a landscape or anything else drafted, please let me know.

Thumbnail by GMan13
Ennis, MT(Zone 4a)

I know a lady in Harrison who has the most awesome greenhouse I have ever seen. Probably would cost $20,000 to build, but her husband is a contractor.

They dug it into ground 3 or 4 feet, ran vent pipes below the freeze line I forget how far, 20 or 30 feet away where they come up outdoors, lets all incoming air cool or warm to 55 degrees year round. Lots of glass on the south side. The glass is all double pane. The walls are straw bale construction so they insulate beautifully.

Back half is seperated from front half of building by a wall with open screening up on top part. Back half has rabbits and chickens, chosen because of their high body heat. She calculated how many she needed for the space involved. In the day the sun heats it, in the night, the critters heat it.

In this godforsaken climate with no other heat source, no electricity, she grows plants in there year round. It has been awhile since I have seen it, and have forgotten the details. But I will be over there this weekend, if you want any more info.

Ennis, MT(Zone 4a)

What kind of floor for the thermal mass?

My brother in law in Boise is building one which will have some huge underground water reservoir for his thermal mass.

Lakewood, CO(Zone 5a)

Water is great because it has a high specific heat. Do the tanks absorb energy directly, or is there thermal collectors? The water would have to be in a black painted container; metal would work best because of it's high conductivity. If the depth of the tanks is substancial, not much of the water would be heated directly. The greenhouse at school had clear vertical acrylic tubes with blue-colored water, blue water absorbs more than clear water. The blue coloring may have also been a treatment; maybe it was a bunch of toilet things. I personally wouldn't use water because you would have to treat the water with something to eliminate funk, and you'd probably have to change out the water periodically. I would use concrete with pre-plumbed drains. Concrete can be stained a variety of colors, and you can do it yourself. I also want a greenhouse to be aesthetically pleasing. There is a liner they poor concrete over that has a value of R-10. Perimeter insulation of the slab is even more important. I would use insulated foam forms (R-40) with concrete and rebar for the walls (this is best, not the cheapest by any means). You could also add a thermal colllector or two, a storage tank, and run heat into the concrete floor. That would keep it about any temp you want, unless there are long periods of cloudy weather. That's the best even heat you can get! I would never use hay bales as insulation. Any living matter will decompose, and it welcomes pests, molds, bacteria, etc. It also takes up a great deal of room. I suppose if you used it on the outside only and periodically changed out the bales, it would be ok. I would also use some sort of night insulation on glazed surface to keep in maximum heat. Low iron glass (double pane, never triple) should be used because of it's high emissivity. The best glass is glass which diffuses the light, evening out the light distribution. The glass looks similar to kinds used for bathrooms; it allows light, but you can't see through it clearly. That's my dream greenhouse, now I just need to hit lotto. I've heard about the chicken/bunny thing. It's a great idea, just not my style and I'm not zoned for that sort of thing.

Ennis, MT(Zone 4a)

I definitely do not want a bunch of chickens and bunnies either, I just admire how she made the whole thing work. Her straw bales are inside the wall, it is all covered in stucco or whatever so it is not just a wall of decomposing straw 3 little pigs style.

I am not sure how my brother-in-law is doing his water reservoir as the project is partially completed and it was too rainy for me to go look while I was briefly there this December. But he is going to be heating it with solar panels, if I understood him correctly. It will be beautiful when he is done as he is an architect, so I am sure of that much! We will see how it grows things when he gets it done.

I like your ideas on the concrete floor for the heating. I would have to get used to not gardening right in the ground like I do in the hoop house.

Centennial, CO(Zone 5b)

OG magazine has several articles a year about thermally regulated greenhouses using everything from water in 55 gal drums to manure.

Solar-powered louvers for greenhouses are available from Charleys and other greenhouse suppliers.

Ennis, MT(Zone 4a)

I looked at how many 55 gallon drums I would need and it was appalling. I would definitely like a solar powered louver system but the wind would rip them right off unless I buy the really expensive ones. I still wonder if they would make it...

Murfreesboro, TN(Zone 7a)

Cool ideas. And although I do NOT want bunnies (even domestic ones for eating), I DO want chickens. The brain has way too much time to think when the weather is frozen outside... floral fantasies, grandios greenhouse dreams... nice drawing GMan13.

Lakewood, CO(Zone 5a)

Mulchmania-
I agree it would be wierd, but I want to go organic hydroponic (we haven't spent enough money yet) for tomato/veggie production where they would be in containers with pea gravel as a medium. Other plants could be in flats or containers. Why get rid of the hoop house? No reason not to keep using it if you have room. 2 greenhouses is always better than one, double your pleasure. My design calls for no drums; it will do fine without. Also, notice my vents are mounted on the side instead of the roof. I was thinking about an attic fan setup with a differential thermostat or a solar chimney(s). I like the solar chimney because there are no moving parts. The overhang will also eliminate most of the overheating. Remember, there's only glazing on the south wall it's heavily insulated.

kmom246-
If I had land, I would want chickens, too. I just don't want them in my greenhouse, kinda ruins the zen, smelling and hearing chickens. Now, I've seen some great chicken coop designs .....

Lakewood, CO(Zone 5a)

Mulchmania-
That straw will break down eventually with or without oxygen, and that is one thick wall (space concerns). Then, what will hold up the plaster and how long will it last? How long until possible cracks and voids in the plaster allow oxygen and pests to penetrate? I'm asking because I don't know. These concerns are the reason I've never subscribed to bale construction. The fact I assume the bales have no structural responsibilities, and it has a framework.

A possibility I haven't presented for wall construction - Rammed Earth
Very cheap, but VERY labor intensive. I would NOT use straw in the mixture for the same reasons stated above. I would use the correct mixture of sand, clay, and aggregate mixed with concrete at a 7:1 ratio, supplemented with fly ash as a strengthening agent. You're right, too much time to think and dream when it's cold.

Ennis, MT(Zone 4a)

Organic hydroponic is not wierd. Either that or I have been around much wierder people than you have, ha!

Planet Natural over in Bozeman has all sorts of supplies for the organic hydroponic people. I have not been drawn to it myself because one of my concerns with growing food is so many of the micronutrients have been lost out of commercially farmed soil over the years. Now, that doesn't mean you can't introduce them in hydroponic growing in various ways, but I am more interested in soil building. Although the soil around here could inspire hydroponic gardening!

I have no desire whatsoever to get rid of the hoop house. I do quietly dream of also adding a large insulated greenhouse where I might grow things like hibiscus... My husband had adjusted nicely to the hoop house, but I think he would flip if did another big greenhouse right now. In fact I know he would, our priorities have been growing our business. I would even have to agree with him. Darn it anyway!

Ennis, MT(Zone 4a)

Actually I don't know much about straw bale construction either. It is not structural, that I do know. I will ask Jenny when I see her this weekend. She has a lot of acreage so wall thickness is not an issue for her. I will take my camera and if she gives permission I will post some photos of it.

Denver, CO

Beatiful drawing- I know some folks who remodeled their 100 year old house wth sunlight angles in the windows in mind.
Can these louvres be inside of the greenhouse? The atrium in the school's library has (tin? Aluminum? Steel?) louvres on the inside of the glass top.

I just talked to a lady (living in a yurt now) who is building a stawbale house. Apparently, the right contruction can hold up for a good many years, (longer than the average homes built now do before they need help) but there is some maintenence in things like you noted-cracks, and all.

I wanted to post a little Welcome for Gman13. Sorry if you wanted to sneak in quietly. I hope you find company in the misery of our odd climate, and perhaps you will join us in the next get-together?
Kenton J.

Los Alamos, NM(Zone 5a)

Strawbale houses are all over the place in New Mexico. People love them. In fact, the feed store where I buy almost everything sells straw as fast it comes in and it is hard to get a few bales for the garden. That is because there are so many straw bale houses going up.
The bales are usually plastered over, and I am told they last a long time. I think straw bales would work very well in a greenhouse and whether the bales ae platered over or not, the owner would do well using bales.

Lakewood, CO(Zone 5a)

I checked out a site with some cool straw houses in Australia built with straw panel. The panels are made by a company called Solomit. I wonder if a US company makes straw panels. The houses are 60 years old. I think it would work better in dry climates. I still like the insulated forms because most of my designs are earth bermed. The forms with concrete and rebar provide the strength needed to deal with lateral soil loads as they are often used for basement walls. This type of construction would last centuries. I forgot to mention that I would insulate a rammed earth wall on the outside. Rammed earth has been around a while (Great Wall of China) I would also employ reflective heat films in key locations, no matter what design I used. A company here in Golden makes a great one. Can you tell my first real job was at a wholesale greenhouse?

kmom246 - You can be my Silver Spring! Sorry, I couldn't resist the Fleetwood Mac reference.

JamesCO - Thanks for the welcome! I guess I've never been known for my stealth. I would love to participate in the next get together, but the Junction is quite a drive. I embrace and love this climate! I would probably be lost trying to design a landscape in other climates because I've become so western focussed. I still try new plants that don't fit the mold. This brings success as well as casualties. As to your questions, I suppose the louvers could be on the inside with maybe a low profile structure outside. I try to limit roof penetrations. If there was a fan and vent on either side like in my picture, a wicked cross ventilation would be generated. The window configuration creates a convective loop, further aiding cooling. Roof vent(s) may be required in the middle depending on the length of the greenhouse, which I would use a solar chimney, and yes the louvers would be inside and operated by pressure.

mulchmania - Hibiscus syriacus might make it outside with a little TLC. Pop some 'Disco Belles' in the middle of your hoop house, add a hammock or two, and crank up some Don Ho. If you've never seen one, you must check it out. Some say zone 5, some say zone 4, but I think it would be safe in the hoop house.

Lakewood, CO(Zone 5a)

Heres the Belle of the ball. Disco Belle that is!

Thumbnail by GMan13
Denver, CO

Hibiscus 'Disco' series: Herbaceous.
http://davesgarden.com/pf/go/40900/index.html
The Fleming Bros hybridized another version that I like:
http://davesgarden.com/pf/go/40908/index.html
I've seen them in zone five- a heap of mulch, good soil, and good siting will probably extend it to 4a, but the key for those suckers is a hot summer to wake them up.

Hibiscus syriacus is a big bush or even a small tree. They wouldn't need a bit of TLC once established- I've seen many here take a real beating and come up blooming.

Gman- I don't know specifics (no one does, unless GreenJay is delighted in watching us squirm) but I think we'll meet in Denver in the spring. It sounds like we might trek up to Vail, I'm sure carpooling could be arranged.

As someone with experience in Greenhouses, have you ever heard of the practice of opening vents with the purpose of letting out oxygen? It sounds preposterous, which is what I think, since I was under the impression that as much as plants do capture CO2 and expell O2, it was a small percentage in the way of actual gaseous mass. But I don't really know! Does anyone know some hard facts?
Kenton

Centennial, CO(Zone 5b)

No, I'm not watching you squirm. I am still planning on hosting some kind of lunch here w/tours of the project gardens I'm working on after the DBG spring sale. And I would definitely like to get to the Betty Ford gardens in Vail, depending on the timing of certain frittilaceous flowers. Carpooling certainly can be arranged.

I don't know about the greenhouses and opening vents, but I do know that I have to open the sealed up bags I keep my rose cuttings in about once a week, or the rooting process slows down. Rooting roses need oxygen near the root zone. Don't know how that would translate in terms of the CO2 exchange for greenhouse plants.

Ennis, MT(Zone 4a)

My hoophouse is so utterly not airtight I have no idea. And the insulated area inside there gets its 8 mil plastic front wall rolled up in the daytimes so often I cannot tell with it either.

It would be fun to come down and join the tour, but I have serious doubts my schedule will cooperate. We will have to see when it comes together. Assuming you would be able to cope with a crazed Montanan in the bunch!

Lakewood, CO(Zone 5a)

I've heard of enriching the air in the greenhouse with CO2, but I've never bought into it. All plants need some oxygen to their roots. I think air movement in general can be beneficial, but not because of O2 or CO2. I'm up for the spring fling, sounds fun.

JamesCO - I was talking about Rose of Sharon in Montana. That's a lot different than CO. A neighbor has a huge one here and it does great, and I've also seen 'Disco Belle' thriving. I've used both in several designs. I was trying to make suggestions for Hibiscus in Montana. Rose of Sharon doesn't like massive snow, this I've witnessed. I've never gardened or designed in Montana, so I can't say without a doubt what will work. I

Denver, CO

Thanks for clarifying that to a mindless fellow in Grand Junction, Gman.
I wonder if the miniature H. syriacus would take the snow better.

GreenJ; not being a real word doesn't stop me from loving "frittilaceous." With any luck, it will be a word that can be used to describe my garden next year.

MM, being crazed is a prerequisute for this group, you know. Montanans? We may be willing to make an exception to allow one or two... ( I was just tinking about your comment on painting and hibiscus colours-have you seen the tropical hybrids with brown, greys, neons, and blue-ish? They are hard enough to beleive in the flesh.)

I guess I'll continue to assume that the O2 dumping thing is bumf- it sounds like some far-flug quasi-scientific thing I would come up with.
(K)

Centennial, CO(Zone 5b)

What's this about Rose of Sharon not liking colorado winters? We have several thriving here. I collected seed off of one this year, and already have babies under lights.

Lakewood, CO(Zone 5a)

I said they don't like huge snow loads, many trees/bushes don't. I said they might not do well in MT.

Denver, CO

Thank goodness I'm not the only one confusing myself. But I expencted Greenjay to be quicker than I.
Yeah, G-man, huge snow loads are often too much for aspen, eh?

Centennial, CO(Zone 5b)

I'm not sure I *did* get it wrong. Our two healthiest ROS are at the edge of the parking lot where the snow crew usually push all the snow off the pavement. Currently they are under a mtn. of 7' of ice & snow. This is a pretty regular thing, and they do fine every year. The ones on the other side of the property are on a slope that also catches a LOT of snow.

Bottom line, ROS is a really, really tough shrub to kill.

Denver, CO

Then the rock salts on that...

Ennis, MT(Zone 4a)

Oh, I sorta missed your comment about tropical hybrids of hibiscus. THOSE are the ones that have me fizzing popping to grow and paint. I think I could possibly manage Rose of Sharon here, but the tropicals are the ones...

Lakewood, CO(Zone 5a)

I never said Rose of Sharon was wimpy, that it was easy to kill, or that it doesn't like CO. I merely suggested it as a possible fit in MT. I've never gardened in MT, so I was steering on the side of caution. I saw some completely destroyed by the big blizzard a couple years back, but then again, many Pines and Spruce were also leveled. Many came out fine, as did some other trees, luck of the draw. It's susceptible, in my opinion, because it has such thick branching, so more branches to break. Everyone is entitled to an opinion. My opinion is based wholely on what I've personally witnessed, not something out of a book. It seems others have witnessed something contrary which has shaped their reality. It's OK that they aren't the same; that doesn't make anyone right or wrong, just different. If you do need someone to be wrong, then let me volunteer. It just not that important to me. I started out talking about Hibiscus to offer a solution to someone in MT with a Hibiscus Jones. I was trying to help. If you really read the posts, I stated that Hibiscus syriacus and Hibiscus 'Disco Belle' like it in CO, and I've used both in several designs. Given what I wrote, I don't understand some of the interpretations that were formed. I'm not in the habit of painting broad generalizations based on what should work, so I offered them as suggestions for MT. They should be fine, but I've never grown either in MT. Have a great life!

Ennis, MT(Zone 4a)

Gman, thanks for the info.

Centennial, CO(Zone 5b)

gee whiz. who knew pioneers had such thin skins?

Denver, CO

G-man; the dangers of all of us reading posts too fast or only the ends of threads (missing the contexts), which we all do, is mild miscomnunication, dont' sweat it, with a person as daft as I in the midst it is bound to happen again.

Ennis, MT(Zone 4a)

Gman, here are a couple of pics of that unusual greenhouse I told you about earlier. Jenny said she used Anna Edey's book Solviva as a major reference, but adapted the information to create this greenhouse for our difficult climate.

The front wall and the short end walls where the doors are do not have straw bale construction. You can see where the wall is wide on the end going towards the back of the building, that is where the staw bales begin and go around the back wall. The high upper windows are for ventilation. The two underground vent pipes extend below the frost line underground 60 feet each and come up. All air entering the greenhouse through those pipes is cooled in summer or heated in winter by the reasonably constant temperature of the earth the pipe goes through.

No heaters of any kind are used, unless you count the 80 chickens that live in the back of the greenhouse as individual heaters. Which is indeed how they function, warming the building at night. You can see the black tube coming out the end wall towards the back of the building. That is how the chickens enter or exit, eliminating windy drafts.

Her plants live year round, with this being the slowest growing time of the year in there. She has various flowers, chard, and kale in particular growing right now. This is in a climate where we can go to minus thirty degrees each winter. It is a remarkable accomplishment.

Thumbnail by mulchmania
Ennis, MT(Zone 4a)

She has one nasturtium plant that is now three years old that has been living in the greenhouse the whole time, once again, without any added heat other than chickens and sun. It is the rounder looking one on the left growing in the pvc tube hanging planter.

Thumbnail by mulchmania
Ennis, MT(Zone 4a)

I forgot to mention that the three year old nasturtium has twice survived in there when the outside temps have hit minus thirty degrees.

I took these photos yesterday when I was over there. Jenny loves to share information with anyone interested in earth friendly pursuits so she said I was welcome to photograph and post it here.

Centennial, CO(Zone 5b)

that is extremely cool. I have seen pictures of bermed-in houses here in CO that use some of the same techniques to mitigate changes in temperature.

Los Alamos, NM(Zone 5a)

I, too, am totally impressed. When I told my husband about the 80 chickens he assumed that it was the chicken poo that heated the greenhouse, but I am guessing not that it is just the earth and their bodies.

Ennis, MT(Zone 4a)

Paj, you are correct. It is a chicken house and has some poo in it, but the chickens are outside foraging most of the day. She actually used a formula based on how much body heat a chicken gives off to determine how many she needs to heat the space at night.

Originally she had a combination of rabbits and chickens as both are high metabolic and generate a lot of heat. But she gave up the rabbits because they had to kill so many of them to get so little meat. She sighed and said, "You only have to kill your nice gentle beef steer once and then you have lots of meat." She does love her animals.

Denver, CO

As we all know, Love is best had with some BBQ sauce on top, if not between two buns with pickles and cheese.

Ennis, MT(Zone 4a)

Spoken as a happy carnivore indeed! ;-)

I am thinking of buying some pasture fed beef sometime this coming year.

Centennial, CO(Zone 5b)

I prefer mine as Tacos al Carbon or Pot Roast, but we all have our own definition of love... LOL

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