In order to build a walapini greenhouse i plan to hybridize several methods of maintaining temperatures. I do this based on my past bad experiences with my lack of ability to do that in my old greenhouse. I have been around greenhouses since I was a child and saw everyone has the same struggles. I’m going to start here remembering what i learned from my many past failures stoking a fire to try to maintain heat in the winter.
My sister taught me things about the greenhouses and plant propagation in that setting based on the several greenhouses she worked at as a horticulturalist. That is what her first degree was in. My siblings and I learned to grow things from the family who has always done it. My uncles were professional orchardists as their occupation. They sold lots of fruit.
Where people fail most often with a greenhouse is on heating and cooling. The good news with citrus is that it’s pretty forgiving both of high and low temperatures. Still it’s best to not go much above 100 or below freezing. In the Phoenix area there is a lot of citrus. And it regularly goes above 110 with blazing sun. Still, I’ve read that some shade is helpful at those temperatures. The area I’m moving to seldom goes much above 100F. A poorly cooled GH could easily reach 130-150 in those conditions. My plan is to remove the poly during the freeze free season, April-October. And perhaps put up 30-40% shade cloth as much for my own comfort as for the plants. And I’ll have stone fruit trees near the GH so shade cloth could protect that fruit from birds. Or I might put shade cloth just over the GH.
I’m not sure if I can use my pond but I know water is 3x better at holding heat than any other alternative. I know about keeping it in the greenhouse in barrels , but I also think i could run a tube deep under water and pull heat from the unfrozen bottom of the pond. I’m researching that now.
I’m planning to use sand because it holds water better than dirt. I may run a soaker hose at the same time.
One of the nearby nurseries has a huge metal frame covered in heavy water proof canvas. With water misting spray fans. The plants are exceptionally lush in there. No light transparency either.
You have all the best tricks from experience doing it that many years. I’m going to try to do my best on this greenhouse system. It is best to spend time planning and not take shortcuts that have cost plenty of people i know and myself included.
The trees still need some more size to them. They are doing very well!
This video is the key to everything and now you see what I’m up to. Remember the photos from the bottom of the page. They are solar panels i sourced with the help of my friends.
Hi @clarkinks So you are going to use solar panels to heat up sand and try to save that heat until it’s needed? What are you going to do with the power from those panels in summer, run ventilation fans?
I won’t do anything with them in the summer besides face them down until the next winter. I have about 200+ panels 300+ watt per panel reserve of used solar panels. I recently acquired them and worked some deals and with the help of friends made a mutually beneficial deal for all of us. I would only use them for DC fans if I need them. The deal stretched our resources but we made it happen. We are not needing anything else like those for awhile. Solar panels are dirt cheap in Arizona also. That is a 65’ truck longer than a semi and not even half the stuff.
Ah Clark, you are the king of wheeling and dealing. And I love to hear your ideas. But I have to say that sounds like a very inefficient way to heat a greenhouse. The sun doesn’t shine much in winter. And solar panels only capture a small fraction of the suns energy. Then there will be losses in that heat won’t be available when needed. Bad cold spells are cloudy. I would think that a more direct way would be better. Like a solar hot water heater and save the hot water in large insulated tanks or better yet tanks buried below your GH. Or use the soil under the GH to save energy from a solar hot water heater. A solar hot water heater should capture more of the suns energy than solar panels.
You are absolutely right and we are using those methods also. I’m using about 5 methods to heat and cool. I have electric back up heat using temperature controlled plugs like these Amazon.com: 2 Packs Thermostatically Controlled Outlet, On at 32°F/Off at 50°F Plug in Thermostat Controlled Outlet Switch for Heater, Waterproof Temperature Control Outlet Extension Cord for Freeze Protect : Industrial & Scientific and wood heat, ground tube heat , sand heaters because sand , solar , and barrels are free to me, a greenhouse in a greenhouse. The greenhouse is catching sun at 36 degree angle made for winter etc.. water barrel heat , ground temperature heating and cooling from the 8 foot depth. Remember why I am using what i am. The reasons are if the grid is down, I’m not watching my precious citrus perish during an ice storm and freezing temps. I simply change over my method to propane, wood, or solar sand filters. I suspect the Amish air conditioner and heater will be all I need most of the time. I dont believe in taking those kind of chances on a single point of failure. My climate is not forgiving to my mistakes. We are debating running pex through the floor under sand over insulation and turning the floor into one big heat mat all winter. Radiators and hot water heaters are common and either will work for that.
8’ below ground level the same as the tubes running out which gather the 52 degrees F air from the ground, the air from the pipes is working as heat and air conditioning. The green house is 16’ wide due to sun angles. The length is 32’ to 40’ . I work in 8’ lengths which keeps me from cutting solar panels or boards. It is much more efficient to build taking 1/3 of the time. There is precious little sunlight in Dec and part of January. Using solar for power many years now , I’m aware of the limitations of dark days for several weeks.
“The winter solstice is the day with the fewest daylight hours and the longest night of the year. However, many places consider early December the “darkest time” because the earliest sunsets happen several weeks before the solstice.”
“January 25th marked the 5th week since Winter Solstice (December 21st) meaning the 10 darkest weeks of the year are done and over with.
“ The five weeks leading up to the solstice, starting around mid-November are five of the darkest of the year, followed by the five after.”
The Chinese know the tricks I’m using they use similar or the same methods. They even use the trick you just taught me @fruitnut fruitnuton the blanket over the glass at night.
The black barrel approach works really well from what I’ve seen, even a few large ones make a noticeable difference overnight. The pond tube idea is interesting though, I hadn’t thought about pulling from the unfrozen bottom layer like that.
