Greenhouse structures to prevent wildlife intruders and survive blizzards

[Mike Konshak]

My ultimate goal is to build something up in the Colorado high country (10,000 feet) and was looking at various options to cover some tillable land as well as to modify the underside of a deck to make it a greenhouse. In one case, a free-standing greenhouse, would have to not only survive snow and wind loading, but also to keep from being run over by free-ranging cattle, deer, elk and possibly a curious bear.

I looked at the Harbor Freight green house but I do not think it is strong enough for this area. A greenhouse built under the deck would be the easiest to protect and would survive the environment. A Quonset hut type of greenhouse with 6 mil plastic sheathing I think would be penetrated by critters. So... some other frame structure using corrugated plexiglass is bubbling to the top of my idea pool, but I would like some way to double-glaze it to improve the isolation and insulation during winter.

Hopefully, you all will give me some good ideas.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Rob Torcellini]

I think the majority of your decision will be controlled by how much you want to spend.  I think you may want to rule out anything that will survive a bear.  Around here, the black bears have no problem destroying the chicken coops, hives, etc.  ;-)

 

I have the cheapo harbor freight greenhouse.  With about $20 in extra parts, you can modify the roof structure to handle a lot of snow.  We had record snowfall this year and mine (almost) survived.  If I had added the 3 supports instead of the 2, it would have been ok....but it did bend in a bit.  It's unlikely a quonset hut will survive much snow.  Most of the nurseries around here take the plastic off of theirs each winter so the frames don't collapse.

[Chris Cates]

Are you going to get enough light under your deck?  Also, I'm no expert on bears, but if I was a bear I'd think a nice aquaponic garden under a deck would be a great place to den up for the winter.  Might wake up for fishy midwinter snack.

[David Waite]

Mike go to Farmtek website they have a bundle of greenhouses. Might consider a wood frame they are sturdy and easy to build. Mine is a tube frame and handles 80m per hour winds  and snow. You can put a electric fence to keep out yogi and the critters. I used recycled windows at the bottom 4 foot to allow me  to vent the house in the summer.

[kl kingston]

Have you considered a Geodesic Dome ? Do a Google search for them. A manufacturing  company is located in Colorado and you can pick it up at the factory. Several sizes and aquaponics can easily be incorporated in the system.

 

 

[Rob Torcellini]

I'm currently building a 33' dome.....it really has a "coolness" factor.  ;-)

[David Waite]

Rob a dome would be a fascinating concept. You would always have a face square to the sun with a dome. Keep us posted very very cool is right.

Rob Torcellini said:

I'm currently building a 33' dome.....it really has a "coolness" factor.  ;-)

[Rob Torcellini]

If you haven't seen the videos, here they are!

 

http://youtu.be/9rn6YtCC670

http://youtu.be/gLIhOglrbmI

http://youtu.be/KHEHVyA7SHw

[Mike Konshak]

Rob, I'm already a subscriber to your youtube channel and watched how you jigged up the components. I'm a retired mechanical engineer in product design so I was impressed that you picked up on the need for fixtures to help you improve the quality. You also did not shy away from showing us your hiccups along the way. Product engineers make a lot of revisions (mistakes?) trying to lower costs and manufacturing time while still retaining quality. I'd rather watch you jump through the hoops first. :o)  I have my own TIG welder which I used to build race bike and robotic chassis so I could bulid all the connectors.

My biggest problem with domes is the amount of labor that might not be accomplished by a 63 year old man and his darling wife. (I'll never build a log cabin again and stay with stick-frame construction).  There's a lot of handling and lifting, and the best way to save one's back is by only having to touch one part once (setting it in place and moving on. All that said, I think a dome would survive the elements, better than anything else. However, if I wanted to expand the section of meadow that is going to grow eatable plants, a conventional greenhouse could be stretched more easily without gaining height in the roof. A dome can get huge in trying to cover surface area, unless you stay with a 3/8 dome or smaller instead of a 1/2 dome, then one has a problem with head clearance. On the plus side the extra height is a good candidate for vertical gardens.

From a solar perspective, a geodesic dome seems to have at least one or more facets normal to the sun at any one time during the year and day, and individual facets could be candidates for solar thermal or solar electric panels. See the diagram I created using your design. Keep in mind I used my Colorado Latitude for the optimal angles.

My biggest problem with any greenhouse, is getting power to it, since I create my own and too far from the grid.

Rob Torcellini said:

I'm currently building a 33' dome.....it really has a "coolness" factor.  ;-)

[Rob Torcellini]

You're still young... you can climb on one of these to build it!  ;-)   I'm sure you've seen the growingspaces domes.  I think they're located in your area?  We don't have a dome company in our area that could make one so it's one of the reasons why I'm building my own.  It may be worth your time/money to just have them do it for you?

 

You're right about the amount of space they take up.  They are an odd shape and it seems like a traditional greenhouse would fit better.  But as your diagram shows, you can get good efficient sun at all angles,  With a 33' dome, there is plenty of headroom for a 3v 3/8 dome.  I'm going to set mine on a small kneewall to raise it up a bit.

[Mike Konshak]

I've been thinking more about the issues of high mountain growing and came to the conclusion that standard green houses all have one (or more) sides NOT facing the sun and because of the low U rating of glazing have an excessive amount of surface area that can lose heat in the winter, and in the summer allow too much sun and consequently too much heat that has to have the greenhouse be vented or cooled.   I was working on ideas for making my south facing deck in a gretoenhouse, and it is hampered by shadowing during the summer, not so much in the spring and fall. To optimize the angles of the winter sun I think a shed-type green house with insulated north walls would be ideal. It lessens the exposure to animals as well. More later...

 

[David Waite]

Mike you need to read the book the solar powered greenhouse. It is right on your thought process. You are right on all accounts. A north wall is a waste and having a shed roof out is right on . The angle on your shed should be about 15 down to give a better shade angle in the summer. Really helps to back this up to a heated structure to take advantage of solar heat in the winter.

[Mike Konshak]

I made a slight modification to what I think would be the ideal greenhouse structure for my 10,000 ft location. I widened it a bit to allow an array of water filled barrels to act as a thermal mass to put heat back into the greenhouse at night after being 'charged' by the sun during the day.The partial roof sheds the barrels during the summer so that it helps cool the greenhouse during the day after soaking cold at night. I'm seeing variations of this design now that I am looking for it, so my engineering intuition seems to validate by what others have done before.  ...and it doesn't take any power from my batteries!