How Double Layer Greenhouses Supercharge Your Growing Potential!
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- Опубліковано 22 сер 2024
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Greenhouses are revolutionizing the world of agriculture, and double layer greenhouses take it to the next level. Join Curtis Stone as he guides you through the intricacies of how double layer greenhouses work, exploring their unique features and benefits.
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About Curtis Stone:
Curtis is one of the world’s most highly sought-after small farming educators. His book, The Urban Farmer, offers a new way to think about farming𑁋 one where quality of life and profitability coexist. Today, Curtis spends most of his time building his 40-acre off-grid homestead in British Columbia. He leverages his relationships with other experts to bring diverse content into the homes of gardeners and aspiring small farmers from around the world. Learn more at FromTheField.TV.
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these " How I do things " vids are great
they have answered a lot of techy questions I have had
Great video! Only complaint that I have, is that as I read through the comments it was disappointing to find that most of the great questions that were asked were not answered. It seems to me as though, that if the creator of the content would answer more of the questions it would benefit his channel. I know that to reply to every question would be way too time consuming, but it seems that there is a LOT of unacknowledged questions in this video in proportion to most other videos that I have watched on numerous different subjects. ... that being said, I do think the double poly wall with forced are in between is a novel idea!
Interesting! I met a man named Richard Nelson, who invented a system where you insert very thin (dry-cleaning type poly)tunnels between the layers at each end of these ducts there was a fan, on which was adjusted a screen, drippping with dishwashing soap & water was dripping . The result was to fill the ducts with gazillions of tiny bulles. Once done with the insulation need, just blow the bubles up against the creen at the other end, recouperating the solution in a closed circuit.
But what was truly mind blowing in his project was that he had placed the greenhouse structure over a surface made of a water retention bassin filled with large rocks opn the inside of the external layer, he had water slowly dripping from the apex. Water was thus heated, and stored underneath the structure.
At night, in the desert, very cold temperature is the rule. Richard's soap ducts system insured a superior insulation against heat loss, thus conserving and slowly consuming energy stored under the greenhouse. I don't know what happenned to Richard or his designs. At the time the Canadian based company he owned with his wife was called Thermagrow.
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Thank you for the information. There sure are a lot of inventive folks commenting and overthinking answers for problems that do not occur. I appreciate the simplicity.
Does the fan say anything about how many cubic feet per minute/ CFM or the revolutions per minute RPM? Thanks
Great video! I work in the greenhouse business and we have installed blower using inside and outside air. Not much difference with condensation but drain holes are helpful. There are pressure relief valves you could use instead of a open pipe. The wiggle wire - great invention!
This is a great system. They sometimes add pressure switch on it to stop the motor when the pressure builds up between layers.
... there’s a damper lid on mine to reduce the pressure if needed ...right on the fan ... ready to change my Polly this week myself ... have a great spring here in zone 6 ...
Sorry I'm late to the party, but I would mount the blower 90 degrees to how you have it mounted. The way you've mounted it now forces the bearings on the fan and motor shaft to ride on the side of the bearing races. This will shorten the life of the bearings, and you'll need to replace the worn bearings or the whole fan earlier, whereas mounting the motor shaft horizontally allows the bearings of the shaft to run in the center of the races. Otherwise, beautiful greenhouse!
You rock Curtis, simple and quick
Why not simply fix the inner layer of poly on the inside of the timber framing? Surely the larger air gap achieved would give a higher R-value.
You'd get exactly the R-value as the thickness of the studs. So 3 or 4 inches means R-4.
I would appreciate a video of the actual installation of the blower into the greenhouse plastic walls. Actually, if you erect another such greenhouse, a video of its erection and covering would be appreciated by me and I dare say, everyone with an interest in such an activity.
The concept is sound but true R-value is achieved by 'trapping' air. With the air flowing wouldn't this just act as a heat exchanger? I want to build a small greenhouse and all your videos are great. Thx👍🏼
Yeah, it's a heat exchanger. He's heating up the space in the winter between the poly walls. Blow the air in from just above the ground in the greenhouse, let the sun heat it between the walls, exhaust the now hotter air into room. It's using the sun's radiant heat to heat the space between the two. Since you're using greenhouse air as the supply air, it being already warmer, you get a little better performance between the walls than you would just with one layer and allowing whatever radiant heating would occur. There is a bit of a blanket insulation effect because the air of the greenhouse and walls is mostly static; it's the same air.
I agree with your concern here. I am not convinced that it is a good idea to blow air in between the two layers of plastic : he might as well have just installed 1 layer to begin with. It would have been a better solution to install some kind of spacer in between the two plastic layers during construction. I imagine peices of styrofoam would work well
He's just blowing the air because otherwise a small tear means that the whole thing deflates slowly and surely. He says as much in the video (4:14), and it's correct that it is unnecessary for just producing a sufficient thermal resistance. If he/the guy who came up with the system knew his film would never have small tears in it, then they would not circulate air at all and just leave the walls as big inflatable mattresses.
The air flowing goes inside of the greenhouse too, so we aren't really worried with exchanging heat from a hot place to a hot place. None of the circulating air is from outside
@@thehealthpolicychannel1229 Since he's using wood-frame construction, he could just staple/attach one layer outside and one layer inside of the framing, and it's an instant R3 or R4 (the space between the layers is how R-values are measured for air at standard temp and press, I think). i'm not sure where he's getting the R5 from, assuming the plastic layers are only being kept apart by air pressure. Pressurizing the air warms it a bit, and the compressed air has higher R-value than ambient.
My idea was to build a Russian-doll sort of greenhouse, with one inside the other. The R-value achieved would be the thickness of the dead air space between the inner and the outer. No blower running all the time.
Why do DIYers always love to hear things clanking and whirring? You know. Like the guy with the wood-gas truck and the wood-gas tractor. Neither have decent mufflers. They just really like the rattle-bang. Probably grew up providing sound effects for their Tonka trucks.
I'd use a small blower connected to underground pipes, to use passive geothermal to regulate the temp beyond that.
@@harrymills2770 It could be that he is concerned about the thermal bridge effect; in your example, the wood framing would transfer heat, whereas if the outer layer of plastic is inflated, there is no thermal bridge. But he should have addressed that in his video.
Curtis, if you put the fan on a variable switch, you can control the pressure and get the inch column of water needed. This way you won't stretch your plastic over time.
Better to let the blower run as intended and release excess air with a valve
This totally make sense! Thanks, Curtis :)
drawing the air from outside will help with condensation
another benifit is it acts like a pillow, absorbing energy frim wind gusts.
I could be wrong but I would think filling it with warm air from inside would be better insulation than cold air from outside.
MrFarmer1997 it's about relative humidity
warm air holds more moisture then cold
warm moist inside air when it comes in contact with cold, the moisture drops out.
happens to ships that load in the tropics , thousands of gallons have to be pumped out.
Curtis is in high desert, or semi arid.
he only has a small problem with moist air.
not practical, do you know how much that much double glazing would cost, and you only need it for the winter.
@Robert Slackware You're not achieving any measurable vacuum for 300 bucks with plastic poly sheeting.
You made a wise choice with the double-walled polyethylene. The pricey Palram Thermaglas 8mm twin-wall polycarbonate is rated at R-1.72, whereas your setup is in the neighbourhood of R-5.00 It's difficult to argue with that!
Thanks for all the great information
Very simple yet very effective...thanks for uploading...need to build a largish (6' x 10') unit for the front of my house for winter flower and shrub protection here in Alabama...great insight now.
Would be great to show the temps outside verses inside. Looks great & gives me some ideas for winterization
great video! more details on how you fix the hoses to the poly in such a way as to support the hose/blower. The question that would be helpful to answer for us is how many CFM does the blower provide? Rather than current draw, what the Cubic Feet per Minute rating is the key variable... Again, thanks for sharing this!
On my greenhouse, I've given up on those little fans. They have crummy little sleeve bearings and just do not handle the long hours of running. But this fan is optimized for producing high static pressure and you won't find a small fan with better bearings that will replace them. I went with a larger fan that replaces the 6 small ones that my double bay greenhouse used to need. (it has poly walls). I have a whole box of little junk fans (that had to be replaced in the middle of the night etc) if you want them.
Merci from Montreal, Canada.
Great idea! Congrats Curtin, and thanks for sharing! What difference of temperature can you reach with this system?
Another great video. You answered a lot of questions I had on double poly. Thanks!
Thank you so much! I am building a passive solar green house in an area of South Africa that has regular frost in winter during the night. Now I was looking for some type of fabric I could use to roll down the plastic cover during the night as insulation. Found nothing so far. Then i revisited your video on the double layer plastic which seems exactly what I need. One concern I had was the fact that it's a curved area - until you moved to speak about your second green house you planned on covering, because that has a curved area too. You didn't seem concerned about that fact. Is it not necessary to put any spacers between the two layers? you just cut the sheet a bit longer then the first one and the blower does it all?
It's a good practice but the air have to be taken from the outside. As you can see, there is a lot of condensation between the two plastic layers. this is due to the condensation of moisture in the warm air that comes into contact with the outer layer.
Fantastic! THANK YOU for sharing! I too have been struggling to budget for the clear corrugated roof panels, so this will be my more affordable solution!
Thanks for your comments! Appreciated. All the best with your gardening/farming. Sincerly, Sunita - From The Field Support Team
Hi Curtis, thanks for all your great information! Regarding inflator blowers if you draw your air from outdoors you will not get the condensation between layers! Thanks for being such an inspiration, keep up the outstanding work!
This is not true from every other grower I've seen. If that works for you, send me a picture of your greenhouse. Nobody I know in a cold climate does that.
Ok, will do. I'm in NH using a Harnois oval tech with blower mounted outside under a small metal hood. Second Harnois has rigid poly roof with inflated side roll up walls. Again, blower mounted outside. Never had condensation between poly film regardless of temps.
Ok, I would love to see how that is played out.
I'm building a SSG off-grid, so will try a fully sealed double skin with a tapped condensation draw-off and a pressure switched on/off for the blower.
Curtis, do you use different types of poly for the two layers? If so, how did you determine what types to use? I'm looking at buying poly for my hoophouse soon. Thanks!
Very very EXCELLENT! Does the plastic have UV protection, and if so how many years is it rated for? I purchased some greenhouse plastic end pieces (at a big discount from Grower's Supply) for my low tunnels that had a coating that allowed sunlight to enter but reflected back into the greenhouse the long-wave heat radiation. Do you buy special greenhouse plastic or just inexpensive local stuff? Your Northern location does not have the intense sun radiation like the South. What is the longest you have had plastic up without it falling apart.
@5:05 that 115V AC fan at 0.65A is then 75W, which is 657kW/h per year of 24/7 nonstop running
Last time I checked with my greenhouse specialist if you are going to blow air in between poly you use outside air that way you don't get condensation in between. But what would research greenhouse people know
@We The People do not bring cold air into greenhouse, that is silly, use dry air to fill inner layer from outside.
Excellent info. Lot's of practical ideas fot not a lot of money.
Could you achieve the same effect as bridging the tubing across panels by doing a couple of bore holes in the wood frame for airflow
I'd like to see what kind of chanel Lock you used to hold the poly and how you hold the poly up
If you take air from outside instead of in the greenhouse for the fan you will get less condensation between the layers.
Greenhouse air is usually pretty humid
I think the exhaust is a bad idea except for, perhaps, reducing moisture in the space between the layers. The ideal situation would be that there were negligible leaks in the system and the fan ran fully stalled and no air circulated. By having the exhaust you are taking air from inside the inner layer passing it in close contact to the cold outer skin and returning this cooled air back into the tunnel. There is no need for flow through the fan - it will run fully stalled and actually draw less power when it does (just as your vacuum cleaner speeds up when you stall it - it does that because the aerodynamic load is less). Ideally, to fan should be servoed so as to keep the pressure just high enough to maintain the gap in the prevailing wind conditions (as a guide, the tip speed of the fan needs to be about 20% greater than the prevailing wind (plus a small allowance for the weight of the polythene to keep it spaced in zero wind).
Thanks for the walk through
I used to have a huge greenhouse but I am working on a new one and would love to have a business like you. I have 3 acres but maybe 1 acre is usable because of the giant trees and a pond. Anyways I picked up a great blower like this at a yard sale this past weekend for $2......I think I paid $70 for my one before.
Hello, great job! I have a question about the exhaust. Are you just pushing back the air between the layers and what vent are you using? Thank you, sir and once again, amazing!
great idea, i love how you have reduced your costs with blowing hot air in between the layers of poly
Have you tried or heard of anyone doing a similar design but without active air-pressurization? Just two layers of laminate with an air gap?
No. I've never heard of anyone doing that.
I have done it -- because i could not finance as formal of a greenhouse yet: I have two caterpillar tunnels and when we took one down for the season we doubled up the poly on the one we left up for winter... went from holding around 40-50 throughout a 30 degree day to between 70 and 80 degrees farenheit. no fans except the couple we have inside tunnel simply for air circulation.
As long as you are sealed up wel dead air is a good insulator
Does the double layer have any benefits during the summer?
That fan looks like a standard blower set-up for auto-a/c or I should say big truck A/C, heating system. Could probably save a few bucks if you just take a trip to you local salvage yard.
Tip really intended for DIY small greenhouse in back-yard people. I understand that in commercial set-ups time is money and warranties along with peace of mind that it will work for an expected duration are factors. Love the clips.
Jeff Streeter yes use one from a car or truck add solar vola no electric cost!!!
@@barbaraedwards3715 Indeed, just have to shell out for a decent solar panel.....and batteries like in case it turns night
Great information and build. Thank you for sharing.
... best of luck with your new greenhouse... hope you have an easy to get to place right by the driveway...easy to get in to and haul stuff too ... I like the heavy weed barrier plastic for flooring...but really a dirt floor works ... figure out how to save and transfer rain water for use in the greenhouse ...going on year 24 with my hobby house ... 10 X 20 Polly hooper ...
Very interesting concept….
I am considering this on my greenhouse
Awesome video and very good technique.
Iam from Ladakh it's a cold desert area lies near the Himalayas in India,Here in Ladakh during winter time this states get cutoff from the rest of the country,means there is no supply of vegetables and fruits, people usually depend on dehydrated vegetables and caned or stored food and due to large population the government is not able to supply cheap vegetables to everyone,once a week in Ladakh people get to see vegetables,the situation is really bad.I have planned and this year I'll begin my project to provide cheap and fresh vegetables to the market,if you can help me out in anyway or if you can visit here I would really appreciate a lot and I'll pay for your stay in India.
Hoping to create a better tommorow for our children's.
Just an idea for free fans.
If you can find a friendly enough furnace installer often times they will have junk furnaces piled behind there shop waiting for the scap man.
Often the fans are still good.
Not only the big squirrel cage but also the smaller draft inducer fan.
Just a thought
surprised no one has said it yet...
but... could just put the 2nd layer on the inside of the studs.
What is the CFM of the blower you are using?
Curtis, awesome channel. I like your greenhouses.
Awesome stuff. Do you have a video about how your "channel locks" are designed ?? Would help me understand how you sealed it and connects the poly to it
Search 'Wiggle Wire'.
Very informative, thanks buddy.
Plant growth is totally proportionate to the sunlight it gets. Cloudy days, plants do not grow as well. Clouds are made of water droplets. By having water droplets forming between your layers of plastic, it will to some degree restrict the sunlight to your plants resulting in decreased photosynthesis. Drawing outside air, which is much dryer will help greatly, more so, if you are direct planting in the soil of your greenhouse like Curtis' second greenhouse, which really bumps up the humidity inside.
Please do an instructional video. Thank you.
Try cold sinks and geo thermal with 4 inch corragated line under under the frost line to use the warmer subterrian air
Now that's inventive .. Yet simple !
On my GH I have 2 layers of poly separated by 1x2 boards on each rafter and stud. The poly is tight so I have a 3/4" gap between the layers. Does this give the same effect as the blower system?
yes as long as the 2 layers don't touch each other.
The blower compresses the air, somewhat, so gas laws say it warms the air, somewhat. Also pressurized air prob'ly has a higher R-value. But you could build the inner layer farther from the outer layer, and achieve whatever you wanted.
Do you have to rack the snow off the top layer to keep that bubble up?
No. It melts on contact.
I like your houses! I am a struggling person who is trying to supplement income by growing some things 3 or 4 seasons long,(not make it a business)i would be happy to add 200 to 400 dollars a month to my income.so you can see, i want to put up something small and cheap. i live in southern IL. January and February are our coldest months. i want to do a double wall system, on a full arch house about 8 to 10ft long.(small)
so my biggest concern is construction costs. i will do all the work myself. but i will likely need to cabbage a blower from a clothes dryer or something.
what i don't know how to do is put the plastic on an arch. do i use a channel lock? is that something i have to make? How? or is that something one can buy? what about the ends? i dont want to hard wall the end if i dont have to. unless its best. (added material costs)
i plan to pick up a blue plastic drum monday or tuesday for $10 (was used for vegetable glycerine)for my water resevoir.
i was planning to lay the plastic out on the flat ribs first. then attach it somehow. then pull the sides together with some load tie ratchet straps. if you see problems in my plan let me know. i dont know how to attach the plastic on the ends.
Curtis I have a question about the benefits of using this in the summer. Does it have a benefit in decreasing solar heat gain or does it actually increase solar heat by trapping?
I can’t find an answer anywhere and hope you can help.
What poly did you buy in that quantity for less than $100? Is it not UV treated or 6 mil?
I wanna try something like this in Quebec. You think it'll be too cold? I want to buy your book too, is it still available? Thanks for all you do!
I haven't found any recent comparisons on youtube comparing 2 greenhouses. 1. unheated double layer inflated vs 2. unheated single layer. There was a study done in 1979 hortscans.ces.ncsu.edu/uploads/o/b/observat_537b7424bc61c.pdf
in summary it basically says in the early hours prior to sunrise there was very little difference in temperature between both unheated greenhouses. The study also highlights a large reduction in direct light from adding the 2nd layer. I have seen others do geo thermal and I can attest personally that the black painted drums being used as thermal mass does great, but I was just curious when singling out the single wall vs double wall if there was any real difference in the hours leading up to dawn.
So that's a 75 watt blower fan. Leaving it on for 24 hours for 30 days (average month) would cost about $8.1 dollars a month (where I live in Alberta, you guys are actually a bit cheaper) so, basically, 8k, net of the 300 bucks for this solution means you can run the fan for 79 years before it would have made more sense for you to do polycarbonate;) Basically it never, ever makes sense to use polycarbonate over this solution;)
You have to replace the poly film many times in the 79 years. poly carbonate lasts way longer that the film.
Also polycarbonate has a higher R value than 5
Don't forget replacing the fan in that 79 years, and possibly you know, running out of industrial society because it has collapesed. No more central electricity grid, polyethyleen sheeting or production of cheap 75watt fans. I also wonder how well this PE sheeting would stand a proper storm or hailstorm.
But lets not let reality get in the way. Reality is a math problem :P
Oh no we have crypto so the power will never go out. lol
@@possibleabundance3709 , polycarbonate lasts 5-8 years, similar to polyethylene. EFTE film ~40years.
What about mid-winter? There MUST be a heat generating system for cold climates (at night time at least).
Curtis, you pointed to the insulation value of the double walled Greenhouse. I guess that was no surprise when you see modern buildings having double or even triple glazing. My question is: During hot weather, does the greenhouseheat up to the point of harming the plants. For instance, this last week has been 35˚C plus every day. Would that cook the plants?
that’s an awesome idea ..i’m thinking of this with a solar panel to run the fan….silly question but don’t you need the sun light to get through the poly?? or is the diffused light enough ??
Nice. You could power the fans with a solar panel.
Of most importance to me would be; snow load. I think you & I discussed this somewhere but couldn't find my name in the comments. You said it melts any snowfall but you're in western Canada and I'm in Buffalo NY. We got over 6 feet of snow in like 2 days in 2014. I can see accumulation per hour or even per minute, far exceeding the rate which any air layer can melt it. Have you gotten any SERIOUS snow and how does 6 mil poly handle FEET of snow? How can just an air gap of just a few inches outmelt the rapid accumulation rate?
Oh, this is years after this video has released so I don't expect a response, but I'll ask a question anyway.
I know this type of structure was made for a greenhouse in the northern United States, where you deal with colder weather, but how do you imagine that this would function when dealing with hotter climates?
I live in Florida more specifically and I'm looking at alternatives to keep a greenhouse at a relatively low temperature to grow lettuce at it's preferences. I'm wondering if the 'air shield', let's call it, would help mitigate the raise in heat as well or even a proportion of the degree to which it helps with colder climates. Thoughts? Opinions?
Basically I just don't want to blast an air-conditioning unit 24/7 which is incredibly expensive and wasteful. haha
What happens to the greenhouse when it snows a lot outside? I can see that the snow would help with insulating however does it put stress on the greenhouse? And how do you deal with that? Also how do you deal with the inside of the greenhouse if it drops a certain temperature? Does that R factor stop the ground from not freezing?
Thanks Curtis for the run down. I’m in Jakarta urban area and how about 500 sqm of yard. I havre read your books and now prepared to grow hear.
With hot topical weather climate whats the best way to start.
Jakarta? Put a stick in the ground and it'll sprout. I doubt a Canadian veggie farmer in a dry climate can recommend how you start in a humid tropical climate. I think you need to learn from what's growable in your area. Start looking at seed catalogues and checking out more local farmers and markets.
If the inlet to the blower was being taken from outside. Would that solve the moisture between the plastic . which I assume if you have air and moisture you will have some type of mold growing. Working an indoor garden is important to have fresh air 2 cycle and control the humidity in the growing area. I assume that's the same with a greenhouse. Thinking about putting my own hoop style greenhouse in.
Thanks Curtis I have learned a lot from you. What do you do in summertime do you still run blower?
Awesome tips, how would you in your opinion setup a 4×10 green house in 120 degree weather during summer and 30 to 70 degrees in winter?
What was that little thingy hanging there?
came across your channel today and was viewing this video. a lot of things got clarified for me Sir. One question , may I know the thickness of the poly I must use .Is 200 micron a good quality ? Please clarify.
Thanks
Do you get bad winds in your area? if so, how do your poly do in high winds? What about your little ones over the garden beds?
Isn't venting the fan counterproductive? The fan should pressurize the space, but definitely not move air. If you are going to release excess pressure, you should do it as close to the inlet as possible to move as little of the air as possible between layers. That fan may be a bit overkill if it needs venting.
Dude thank you for this video!!! I never would have thought of doing this!!
seems like a cold circulating pump to me. would be a loss not a gain if it had flow. Maybe try lower the pressure and seal all leaks. use a smaller pump. But air movement is a loss and it would be counter productive of the first layer.
Hello. Awesome information. Thank you. Where do you purchased the poly? How long will it last?
whats the temperature difference between the outside and the inside of the greenhouse during the winter?
hello and thanks for sharing do you have another video on the actual construction thanks i live in the middle east where temp can get to low 50c during peak of summer and it would really help if you can share how its done..thanks..so much
Luv your vid's Curtis & that u share so much info 4 free, but being an engineer & student of science I hav 2 push back here. Your setup is not insulating but rather U-r heating the walls w/ inside air & that heat radiates out thru the single outside layer of poly which is R-zero.
If u wish 2 insulate, u'd want dual poly layers trapping STILL air which is approximately R1/inch
Could you post where you get your Poly for your greenhouse? $300 for a double layer system that big seems like a great deal. Please let me know when you get a chance. Thanks Curtis! Cheers.
The link for caterpillar tunnels is on my website. You should be able to get poly from Farmer's Friend. I buy it locally, but if you want to buy it online in the US, go there.
2 questions: Is there some sort of guideline for knowing how powerful a fan you need for different size greenhouses? And when you install the poly, do you need to leave some slack so that their is more separation between the layers?
no need to intentionally leave slack, there will all way be some normally occurring slack. too big of a gap will not be good, convective currents can occur, reducing the insulative qualities of double poly
Where did you get those galvanized 45,s you used for your hoops?
What do you do with it summer? how do you deal with heat?
is it a better idea to install two layers with a bigger gap between them like 4 inches or more and without using a blower? are you losing BTUS BY pumping warm air from the inside between the two layers?
Good question.
Yes, heat is being lost but a smaller gap is better. It takes less energy to maintain it but expanding it will not increase the R value.
The air layer at near the inlet is being cooled by conduction with the exterior. At some point, several feet from the inlet (farther from the inlet for a 4" layer than a 1" layer), the air is so cold it is being warmed by conduction with the interior layer. There is turbulent mixing through the entire closed volume so it doesn't matter how thick the layer is. The rate of conduction is directly related to the difference between the two temperatures. By providing two conduction layers between the interior and exterior, the total conduction is lower.
Putting in 2 layers of air would require another layer of poly but that begins the diminishing returns on investment. It would entail a complicated bit of construction every 4 or 5 years.
To work for the entire greenhouse, the assumption is that total heat gain from sunlight is greater than total loss by conduction.
Yeh, this makes absolutely no sense at all. I was thinking the very same thing right from the get go.
It makes a lot of sense when you factor in building the structure to create a 4" gap.
@@briansmith6824 why is a smaller gap better? If you have a wider gap you don't need a blower to keep up the gap. Only reason for the blower is to keep the plastic separated as it might fall/stick together with a small gap.
Does this work for hot climate areas?
My brother mentioned this method to me a couple days ago. I like where this is going
R=5 insolation factor ? Are you guys sure about it ? Do you have a technical documentation about it ? Can't find anywhere.
double poly has a k-value of 4
Dynamic modeling and simulation of greenhouse environments under several scenarios: A web-based application
Efrén Fitz-Rodrígueza,∗, Chieri Kubotab, Gene A. Giacomellia, Milton E. Tignorc,Sandra B. Wilsond, Margaret McMahoneaDepartment of Agricultural and Biosystems Engineering, University of Arizona, 1177 E. Fourth Street, Shantz Bldg #38, Room 403, Tucson, AZ 85721-0038, USAbSchool of Plant Sciences, University of Arizona, 1140 E. South Campus Drive, Forbes Building, Room 303, Tucson, AZ 85721-0038, USAcNatural Resources Department, Haywood Community College, 185 Freedlander Drive, Clyde, NC 28721, USAdDepartment of Environmental Horticulture, University of Florida, 2199 South Rock Road, Fort Pierce, FL 34945-3138, USAeDepartment of Horticulture and Crop Science, The Ohio State University, 248B Howlett Hall, 2001 Fyfee Court, Columbus, OH 43210, USA
is the blower really necessary? wouldn't you get the same effect by stapling one layer of the poly on the inside of the beams and posts and wrapping the other on the outside?
Try it.
@@offgridcurtisstone I will! 😊
First time I’ve seen one of your videos. It was very informative and I get it. My question is, the blower you talked about, is it to strong for a greenhouse the size of maybe 8x8 or 10x10? Thank you
How's your mold ,is this the first year you have done this ?