# Greenhouse Problems



## BonnieLorraine (Jan 23, 2011)

Ok, so this isn't really a vivarium, but it's for vivarium plants, so it kind of counts >.<

I have a 8' x 12.5' greenhouse, double walled with an automatic vent on the front wall and an automatic vent with an exhaust fan on the back wall, thermostat is set to 80 degrees, and a manual vent open above the front door. Here's some pictures of them Greenhouses For Sale | Sunglo Greenhouses | Custom Greenhouse Kits if anyone wants to see the general layout. It's covered in 70% shade cloth, and I have a swamp cooler sitting on the walk way just inside the front door, back aimed at the front automatic vent, front aimed at the exhaust fan, that runs from 9 am until about 7 pm. There are 10 mist heads installed under the benches, aimed at the pea gravel floor, that are set to come on for a half hour 4 times a day. Now for the problem, it's currently 77 degrees in my yard, it will easily hit 120+ degrees without the fans and vents on, it hits 105 if I have the fans and vents open, and it hits 93 degrees with the swamp cooler on. Even with the swamp cooler and mist system, the humidity still hits 40% or below within a half hour of the mist system going off, and if I have the mist system running nonstop the temp drops to 84 degrees but the humidity still won't go above 52%, even with the floor completely drenched. I'm so out of (affordable) ideas, and was wondering if anyone had any new ones?


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## tachikoma (Apr 16, 2009)

Sounds like the humidity is fine near the bottom, so raise the mist heads to the top of the green house so humidity falls from the top down. I bet this would help with overall temp and humidity.


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## epiphytes etc. (Nov 22, 2010)

Is building a wet wall out of your budget? It would be more efficient than a swamp cooler, as long as you keep all vents other than the exhaust fan closed.


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## BonnieLorraine (Jan 23, 2011)

It's not really humid, just wet. I put it under the benches because it was on the ceiling of my shade house, and rotted some of the plants. Unfortunately I don't think this kit could really be modified for a wet wall, and they start at around $700 >.< I was looking at humidifiers, but those are pretty far out of my budget as well.


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## Pacblu202 (May 8, 2012)

I'm with tachikoma, if you have the most falling like a rain system it would hit more of the air dropping the temperature in the process. Also, love to see some picture!


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## erik s (Apr 12, 2010)

Had some of the same problems with the greenhouse at my place...sooooo my first question is does the shade cloth cover the entire house??? Also is the swamp cooler blowing the air out of the house or is it making it circulate around?? Just some thoughts...on my greenhouse we cover the top half with 70% shade and had to cover the sides with an opaque covering.. all the misters were up high, that allows some of the water to settle on the sides and evaporate...


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## BonnieLorraine (Jan 23, 2011)

Nothing to really photograph yet, there are only two plants in there, the others had to be rushed back out yesterday lol (so far the begonia rexes I have in there seem ok).

I was looking at this fan mister Misting Systems, Water Sprinklers, & Mist and Irrigation Supplies from ACF Greenhouses. I could strap it on to the front of my evaporative cooler (it has a large round fan inside), and leave it on full time without using nearly as much water as leaving the mist system on (2 gph vs. 5gph), then just leave the mist system coming on occasionally to wet the floor. 

To make up for lack of pics of my greenhouse, pics of my shade house


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## erik s (Apr 12, 2010)

Bonnie...also check-out cloudtops.com


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## Pacblu202 (May 8, 2012)

That is a lot I broms! I am so jealous! I'm going to have a nice greenhouse when I get my own house


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## BonnieLorraine (Jan 23, 2011)

The shade cloth covers down to the benches, so there are maybe 3 feet uncovered on the bottom. I'd like to cover the back wall, that does get some light, but I don't think the white paint is safe for plexiglass greenhouses? The ceiling is only 7 feet high, so if I mount it in the ceiling, the plants will get wet.


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## epiphytes etc. (Nov 22, 2010)

From your pics it looks like you have no plastic, just the shade cloth. Is this correct?


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## BonnieLorraine (Jan 23, 2011)

Oh, that's not the greenhouse. The greenhouse is the same pictured on the link on my first post. My shade house hasn't gone over 89 degrees, wish everything were being that easy >.<


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## Pumilo (Sep 4, 2010)

So you have a greenhouse and a shadehouse, but you do NOT have shade cloth over the green house, is that right?
A lot of reefers attempting or running coral greenhouses, use shade cloth over the top.


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## BonnieLorraine (Jan 23, 2011)

I have 70% shade cloth over the top of the greenhouse, which extends down the sides to the top of the benches.


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## epiphytes etc. (Nov 22, 2010)

Oh, guess I missed that part. Do you have the regular black shade cloth? I find white can make a few degree difference, but doesn't last as long. What size cooler do you have? Maybe you could upgrade and/or add another.


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## Brotherly Monkey (Jul 20, 2010)

just guessing, you'll likely need to figure out a system of cooling that doesn't involve venting the humid air out, like an ac (though, even that will remove humidity).


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## BonnieLorraine (Jan 23, 2011)

I have the regular black on the cooled greenhouse, and the uncooled greenhouse has the aluminum shade cloth (that one hits 125-130 degrees in the afternoon). The swamp cooler I have is rated for about 400-500 sq feet, it used to cool the garage back when I bred chameleons. I don't really see a regular AC working too well, our house dips from 50% humidity to 35% when I turn our wall AC on. The shade house stays relatively cool because it's on the side of the house that gets shade from a giant pine tree in the afternoon, but both the other greenhouses are out in the open yard. I'm wondering about maybe building a lattice wall on the wall of the greenhouse that gets afternoon sun, it would block some of the light, but would help with cooling.


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## ghostpilot (Dec 29, 2011)

Would it be possible to elevate a large tarp over the greenhouse? I would get one that's blue on one side and silver on the other with the silver side up to maybe reflect light away. It may look kind of whitetrash, but if it could save your plants it may be worth looking in to.


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## epiphytes etc. (Nov 22, 2010)

Lattice would be alright. The problem with a shade structure on the inside is it really only blocks light from reaching your plants. The heat from said light still gets trapped behind the greenhouse covering. You'd be far better off adding the lattice to the outside.


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## jacobi (Dec 15, 2010)

Rig up a simple frame. 4 posts at the cornes of your greenhouse walls. A foot or two wider than the greenhouse. Simple frame connecting the poles. Couple support beams. Then you can cover your greenhouse with whatever you want and keep a gap between the top of the greenhouse and whatever you use. Should be simple and cheap and quick. Plus you can easily cover and uncover it depending how you set it up. My dad's trick.


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## parkanz2 (Sep 25, 2008)

Also what about thermal mass? Not sure how much room you have in there but you could add several barrels full of water. Large, 55 gallon plastic trash cans or similar would probably work well and are quite cheap from a Home Depot or similar. The water cooled at night would help maintain a more consistent temperature as the sun heats things up throughout the day. 

I guess a good question is, how cool has it been getting at night?


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## BonnieLorraine (Jan 23, 2011)

I meant the lattice on the outside, I could grow some of our vines up it and shade the outside of the structure. I'm going to try it tomorrow, have some plastic lattice I can just set up on two of the sides and see if it makes a difference. That's a really good idea Jacobi, I might have to try that if this doesn't work. And Max, it's hitting 65 degrees at night, and 85% humidity. I could try some trash cans in there as well, just been worried about mosquitos.


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## Pumilo (Sep 4, 2010)

Good idea, Max. The coral greenhouses rely heavily on thermal mass using huge vats of water, or barrels of water.


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## suztor (Aug 14, 2011)

Petsmart/co has these sinking tabs that keep mosquitos dead. And are safe to put in animal drinking water. Seems its used often by people who keep horses. I used to use it in dog water bins when they were outside dogs (not my choice) 


Or just put bubblers in there to keep the water moving and mosquitos won't want to lay in there
~Sue


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## Rusty_Shackleford (Sep 2, 2010)

An even easier solution to the mosquito issue would be to put a good layer of olive oil or wesson oil on top of the water in the barrels. Mosquito larvae actually breathe air and they have to reach the surface of the water to have access to atmospheric oxygen. If there is oil on top the water they will suffocate. This is why you never see mosquito larvae in water with an oily surface film. 


Sent from my iPhone via Tapatalk


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## parkanz2 (Sep 25, 2008)

Rusty_Shackleford said:


> An even easier solution to the mosquito issue would be to put a good layer of olive oil or wesson oil on top of the water in the barrels. Mosquito larvae actually breathe air and they have to reach the surface of the water to have access to atmospheric oxygen. If there is oil on top the water they will suffocate. This is why you never see mosquito larvae in water with an oily surface film.
> 
> 
> Sent from my iPhone via Tapatalk


I like this idea though I also wonder if "trapping" the water beneath the oil layer will prevent evaporative cooling. I'm not sure how important this is when water is used as thermal mass, though.


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## skanderson (Aug 25, 2011)

the vats of water are not for evaporative cooling, they only function as a thermal mass. personally i would just completely fill them and then cover them completely. another option that i am considering is the 250 gallon food grade square plastic containers. you can find them for a reasonable amount on craigslist or ebay, and being square they fit under the benches better. i am going to use them for heat retention in my greenhouse this winter. you may get some ideas for cooling on one of the gardening or orchid websites. i always empty my greenhouse in the summer and just put sensitive stuff under shade cloth. my only possible idea is that if its cooler out than in put in a big exhaust fan and mist over the air intake vents. good luck and keep us posted the pics look nice.


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## motydesign (Feb 27, 2011)

Bonnie, maybe a few shots of the actual green house and the setup might help. i have questions on the swamp cooler location. if installed correctly should give you some serious delta in temps, but if installed incorrectly is just a big ceiling fan.


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## BonnieLorraine (Jan 23, 2011)

The swamp cooler currently drops it about 10 degrees when I turn it on, but I think it could do more. I think part of the problem is the front intake vent is located under the bench, but the closest I can get the intake on the swamp cooler to that vent is about 3 feet away, thinking of getting some aluminum ducting so the vent is hooked up directly to the cooler and all air coming in is fed directly through the swamp pads. I'll try to snap some pics this afternoon.


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## bobrez (Sep 10, 2011)

skanderson said:


> the vats of water are not for evaporative cooling, they only function as a thermal mass. personally i would just completely fill them and then cover them completely. another option that i am considering is the 250 gallon food grade square plastic containers. you can find them for a reasonable amount on craigslist or ebay, and being square they fit under the benches better. i am going to use them for heat retention in my greenhouse this winter. you may get some ideas for cooling on one of the gardening or orchid websites. i always empty my greenhouse in the summer and just put sensitive stuff under shade cloth. my only possible idea is that if its cooler out than in put in a big exhaust fan and mist over the air intake vents. good luck and keep us posted the pics look nice.


Too go along with this, if you can locate your intake vent low and from a shaded spot... should help


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## motydesign (Feb 27, 2011)

BonnieLorraine said:


> The swamp cooler currently drops it about 10 degrees when I turn it on, but I think it could do more. I think part of the problem is the front intake vent is located under the bench, but the closest I can get the intake on the swamp cooler to that vent is about 3 feet away, thinking of getting some aluminum ducting so the vent is hooked up directly to the cooler and all air coming in is fed directly through the swamp pads. I'll try to snap some pics this afternoon.


bonnie, is the return air (the air that is coming across the pads) from outside the green house? if the air isnt being drawn from outside across the pads, you only get cooling until the air inside the house is saturated and then the swamp cooler only acts as a circulation fan.

possibly give this picture a try

i know a lot of green houses use the air inside as the return air, but possibly the size of the green house is limiting your cooling capacity.


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## littlefrog (Sep 13, 2005)

Heh.. When I had a greenhouse it would seriously cook in the summer, I just had passive ventilation. Even with four endwall vents and the roof completely open (it hinged up, kind of neat), it would get well over 110 in there all the time. A few thoughts on my end, coming in late.

1. Just because you already have one layer of shade cloth, doesn't mean you can't add another. Get another sheet of 60+% and throw it over the top. 70% + 60% doesn't equal 130%, don't worry. 

2. I think regular white latex thinned with water (1:1) is safe for plastic greenhouses... Might want to experiment. It washes off over time, you need to re-apply every spring. You can buy a special shade paint, but as far as I know, white latex is the same thing and cheaper.

3. I used to have two thousand or so gallons of water in 'ponds' under my benches. To avoid mosquitos, I just put a few goldfish in each pond. I don't know if the ponds helped keep it cool, but when I had droughts or long very cold spells, that extra water was really useful.

4. You can make a simple 'wet wall' by getting a water pump, an eavestrough, and a drill... Drill holes every inch or so in the trough, hang it up high, and let the water dribble down a sheet of fiberglass or acrylic. It will grow some serious algae, and if you are lucky some moss you can ship off to frog people, and it isn't as effective as a wall you blow water though, but it will help...

5. Honestly now that I've moved back under lights I'm having a much easier time with summer... I put as much as I can outside in the summer, and the rest stays under lights in the barn. If sun is really an issue, maybe you could black out the roof of the greenhouse entirely, and invest in a few LED grow lights (the big ones). Light from the walls + LED would be cooler and probably at least as efficient? It is a thought.

6. Invest in plants that can take the heat, and move everything else indoors for the summer... I used to move masdevallias and cool growing orchids inside in may, and outside again in september. Kind of a pain.


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## littlefrog (Sep 13, 2005)

parkanz2 said:


> I like this idea though I also wonder if "trapping" the water beneath the oil layer will prevent evaporative cooling. I'm not sure how important this is when water is used as thermal mass, though.


Coincidentally, I just was at the store looking for pool supplies and they sell a magic 'pool warmer' which was a little ball that you float in the pool that dispenses a little bit of oil over time. The idea (as stated on the label of a rather overpriced little ball) was to put a thin layer of oil on the surface, which keeps the pool warmer by decreasing evaporative cooling. Just what you said. It was claiming 5 or 10 degrees difference, which may or may not be true, I'm not paying 30 bucks for a stupid floating ball to find out. *grin*


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## BonnieLorraine (Jan 23, 2011)

Ooh, those are some good ideas Rob, thank you! And thank you to everyone, you've been giving me some great ideas and stopped me from pulling my hair out over this heh.

Here's the current greenhouse layout, the shadecloth is off center because it gets afternoon sun on the right side, which is where we're thinking of putting up the trellises.










My poor little test subjects



























Heat wise it's doing ok today, it's 90 in the greenhouse, and 85 out. With just the fans and vent last week it hit 105 when it was 82 out. Humidity is still being a bugger though, think it's in the 30's in there (my humidity meter bugs out when it drops below 40, and starts reading 1% until it comes above 40 again.


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## Manuran (Aug 28, 2007)

I was going to ask a question about the shadecloth earlier as it sounded like that was the problem, but that picture answers it. I think you have to make a space between the shadecloth and the structure. And as Rob mentioned, 2 layers would really help. If you can space the layers, even better.


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## BonnieLorraine (Jan 23, 2011)

How do I make a space without building a giant frame?


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## motydesign (Feb 27, 2011)

Bonnie, you have your shade cloth installed how you are suppose to, but i think that an air gap between the shade and the house could really be an improvement.


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## Manuran (Aug 28, 2007)

Not sure how windy your area can get, but the first thing that comes to mind if you don't want to build a frame is cable and grommets and ties.

The shadecloth itself can get quite hot in the sun, by not having the air gap, you are just transferring the heat into the greenhouse. It won't fix the problem completely, but any heat you can minimize means you can close the greenhouse up a little more to keep your humidity up. Of course the best solutions cost money, which hopefully you can implement in the future. Or start planting some trees to mitigate that afternoon sun!


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## LarryLee (Jan 15, 2012)

bonnie you might go to local farm supply place andcheck out plastic tanks for watering live stock...then home depot or lows for garden pond fountain sprayer?? makes the water spray like a sprinkler then falls back into tank, im having a hard time explaining exactly what I mean but it would work. 
Good Luck
Larry


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## littlefrog (Sep 13, 2005)

And the greenhouse is pretty small. Very hard to control any variable (heat, humidity, etc) in a small greenhouse. More volume gives you more 'buffer' against wide swings of conditions. That is just the breaks, and you work with what you have, of course. More shade is your best option. I'd run a second layer of shade cloth over the whole thing, right on down the sides and endwalls, anywhere that isn't a vent. One way to get at least some of the shade cloth off the walls of the greenhouse is to stake out the edges of the shade-cloth on lines (basically build a tent). Your stakes go a couple feet (or more) away from the base of the greenhouse. Cloth will touch at the top, but not at the bottom. Use _LONG_ stakes though. I've pulled my share of stakes out of the ground in even a mild windstorm. I've also been known to use cinderblocks as stakes (or in addition to stakes).

I don't know what the humidity is outdoors, but if it is somewhere even close to sufficient I think I might take the end-walls off the greenhouse for the summer. 

Something else to consider, since I didn't realize the greenhouse was empty (or is it full since you took the picture?). The plants themselves will regulate humidity to a great extent. Once you fill that puppy up with plants your humidity will stay much higher. The miracle of evapo-transpiration... Not saying it will be high enough (that is hard if you have to vent a lot of air to maintain temperature), but it will be a lot higher than zero...


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## motydesign (Feb 27, 2011)

im not sure i agree with another shade sheet, but i could be wrong (this isnt my expertise), but wouldnt that negate the available light Bonnie would have?


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## BonnieLorraine (Jan 23, 2011)

It's currently empty. I did have a bench half full, but when they started to die within two hours I ran them back in the house. It's currently at 102 degrees and 23% humidity, and while I know the humidity will go up with the addition of plants, I'm terrified of risking them like that.


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## pdfCrazy (Feb 28, 2012)

Bonnie, as I read through the thread, a number of things came to mind. As I got to the present, many people had in some fashion, mentioned what I was thinking. But, I'll say it anyway. I have worked in, and set up several greenhouses (employee) and have a couple years experience. #1 The way a swamp cooler works and how effective it is, is due in large part to the humidity level of the air you are trying to cool. This is why swamp coolers are relatively worthless in areas of high humidity. The evaporation of the water from the swamp cooler is what creates the cooling effect. If your air is already saturated with humidity, your cooling effect will be drastilcally reduced. A portable swamp cooler is not the ideal device to use for a greenhouse. This is because the air your are attempting to cool is just being recirculated within the already (fairley) humid greenhouse. A wet wall IS the best way to go, they will dramatically reduce your temps if put together correctly. But, there are cheaper ways. Large (non-portable) swamp coolers can be modified to blow into a greenhouse (from outside the greenhouse) with dryer vent, or somethign similar. Alternatively, if you have access to a good greehouse supplies house, it not difficult to manufacture your own functional wet wall for MUCH cheaper that a prefabricated "kit". Its just the cooling pad, a sump to hold the water, a pump to circulate the water, soem hose, and frame it all together. It would be a little heavy on the labor, but could be done for probably less than a couple hundred. Its quite possible to use materials that are not designed for this purpose in mind that are much cheaper. Been there, done that, for 100ft x 20ft greenhouses.


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## pdfCrazy (Feb 28, 2012)

Also, I agree whoele heartedly with the air gap between the greenhouse and shade clothe. Most shadeclothe is black, and black absorbes heat, and the material used is usally rather dense, like pvc or rubber or polyethlene. These act as a heat sink, and will transfer heat right into your greenhouse. Much of the time, these shade clothes can be suspended with poles and cables above the greenhouse. Even a foot or more is fine.


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## jacobi (Dec 15, 2010)

I'd go with white shade cloth.


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## littlefrog (Sep 13, 2005)

motydesign said:


> im not sure i agree with another shade sheet, but i could be wrong (this isnt my expertise), but wouldnt that negate the available light Bonnie would have?


I believe there is a formula for calculating the actual shade percentage when you have two overlapping pieces, but I don't know what it is. When I was in the greenhouse I had two layers of 60% shade (aluminet) in the summer, and (in theory) one in the winter. I say in theory because while that was the plan, in practice I rarely got the second sheet off for winter... Had plenty of light, even though your intuition would say it would be dark as a cave in there. Remarkably, I had very little trouble blooming very high light plants. I did have a bit of trouble keeping full color on bromeliads in the winter, but that may have more to do with the number of days the sun is actually visible in a michigan winter more than the shade factor.

Here is something cool... Soap bubble insulation


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## BonnieLorraine (Jan 23, 2011)

Ok, so I think my plan of action is this, based on every ones recommendations.

1. Build a frame over the greenhouse to suspend the shade cloth. 
I'm going to head to home depot today, grab some pvc T's, 45's, and 90's, plus some cement to make pole holders, and see if I can raise it up about a foot. If I still need 2 shade cloths, I can leave one suspended, and a lighter colored one or an aluminum one strapped to the greenhouse. I have an 8'x10' aluminex one currently unused I could test it out with.

2. Add some giant rubbermaids with water to act as heat sinks.

3. Build a frame to support trellis outside the right and back walls, to block the afternoon sun. Someone suggested growing trees on those sides, but I think that would take a bit too long.

4.Build a small box around the intake vent, cut out a large hole, attach aluminum duct, and attach that to the back of my swamp cooler so that all new air into the greenhouse is forced through the swamp cooler.

5. Attach a 4 mist head fan fogger to the fan on the swamp cooler, so not only is the air pulled through the pads in the back, but blowing out fog from the front. Already ordered this, should be here next Weds. It's only 2 gph, so I figure I can leave it on 10 hours a day during the summer.

How does that sound?


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## skanderson (Aug 25, 2011)

sounds like you are doing the right things to start cooling it in there. before going to 2 layers of shade cloth i would try out the alumex cloth. they supposedly reflect away the heat/light and do a better job cooling greenhouses.


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## motydesign (Feb 27, 2011)

i think you are going to have a nice cool green house when your done!


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