Up, up and not away!

Hello azee_2009, OK I originally thought it was going to be a rooftop greenhouse, but after rereading your second post I wasn't sure anymore. As far as the construction I used to build mine, it could be applied to a rooftop situation. By just building a sturdy base for the electrical conduit posts/poles. Similar to the baseboards I made for mine. The weight of it will keep it in place. The poles for my greenhouse only go down in the ground about 8-10 inches, and there is no cement holding them down (just the weight of the greenhouse structure itself). I just posted the link/information to give you some ideas. That greenhouse looks much nicer than the one I built. Although much more expensive too. Not including the subterranean system, and the hydro systems inside, I built my whole 10 by 20 foot greenhouse for about $800. Ya, heat will be challenging. Our outside temp today was about 92 degrees, but the temp inside the greenhouse was 108 degrees. When the temps here reach the 120 mark, greenhouse temps would likely be around 140-150 if I didn't have a multi tiered cooling plan. Cross ventilation is great in some circumstances, but it wont help much at all to blow 120 degree air on your plants when it gets hot. Given the best circumstances, swamp coolers may bring the temps down about 20 degrees. But if humidity isn't carefully controlled, they may only provide a difference of between 5 and 10 degrees at most of cooling effect by themselves. Just to clarify, when I mention high humidity, I mean in the greenhouse. That will depend a lot on temperature inside the greenhouse, water vapor given off from the hydroponic systems inside. Not to mention the biggest factor, how many plants your growing, and how big they are. Plants breath out water vapor (called transpiration). The water vapor (relative humidity) in the greenhouse will get higher and higher unless it's ventilated. But ventilating a cooler greenhouse with the (hot) dry outside air will only heat up the inside of your greenhouse. I have searched the web a lot & every where i have read that Double Poly Sheet that makes air pockets between them retain heat within the greenhouse & reduce heating costs about 50% compared to single poly coverings. So how would i be able to use it. As i have to fight against high temperatures. The air pocket in-bitween the two layers of poly is an insulation pocket. Air pockets are the best insulation there is. Insulation will protect against heat just as easy as it does against cold. If your greenhouse is cooler than it is outside, the insulation (air pocket) will help keep your expensive cool air inside the greenhouse stay cooler longer. If you have no way to cool the inside of the greenhouse, then it wont help much. The air pocket is just insulation, not a cooling or heating layer. It just helps block the heat transfer from one side to the other. Blocks heat from getting out during winter, and blocks against heat from getting in during summer. The 4-5 inch's between both layers you describe should be plenty. Typically it's only about one inch between layers. Though I would expect that you will still get much better results with a air blower between the two layers. The reason is if you blew the cooler air in between the layers, it won't give the air pocket a chance to heat up. Thus keep the heat transfer between the inside, and outside layers to a minimum. I want to know the link & name of software you are using to create 3D images. I want to download it to make someone understand what i mean. I use a free program called Google SketchUp. They have a pro version you can pay for, but I've always used the free version, and like it very much. I save all my drawings into a folder so I can expand on them later without starting over. Before you post your drawings, you'll need to remember to export and save it as a 2D image. Otherwise it wont be in jpg. format, and people that don't have Google Sketchup wont be able to view it. Before I built my greenhouse, I did a lot research online to figure out what would work the best for me, as well as my budget. Here are a bunch of the links I have got bookmarked from those searches. I know it's a lot to read over, and it's been a long time sense I looked through it myself. But a lot of it is in lists of topics. I just read through what was of interest to me. Arched Greenhouse PRESENTATIONS REFERENCE SOURCES Horticultural Engineering Greenhouse Energy Cost Reduction Strategies POLYTHENE GREENHOUSE FILM FACTS Chapter 11- Greenhouse Site Selection Chapter 12- Greenhouse Structures Chapter 13- Greenhouse Control Systems Chapter 14- Greenhouse Energy & Resource Alternatives "Greening" the Greenhouse Greenhouse Glazing Greenhouse Energy Conservation Strategies Greenhouse Energy Conservation Strategies: Temperature and Scheduling Managing Greenhouse Temperature

I am new to hydro so need to know the following too: 1: Yes, I know these all crops can be grown in hydro but I am talking about to grow them in single 20 x 16 feet greenhouse alltogether at the same time. For example: If all the four crops can be sown on 1st May 2012....? Plz re-confirm. Moreover should I maintain greenhouse temp at 78f range for each four crops from seedlings to full maturity or there will be some variables? 2: If the pollen grains (cross pollination) of any kind of vegetable effect any other kind of vegetable resulting in deformed fruit shapes, un-uniformity or show adverse reaction in any way..? For example cross pollination among tomato, bitter gourd or watermelon? 4: I have an idea to use a fan for a pollination purposes. I want to temporarily place a fan under targeted plant & blow air upwards for 30-60 secs daily that may spread pollen grains in a small scale backyard greenhouse. Please comment. I have a diagram in a link below & that is self explanatory. 5: Is it necessory to maintain humidity in greenhouse....? I don't want to use eveporationg cooling pads in my greenhouse. If humidity is necessory how much average percentage it should be at for all four crops grown at same time in a single greenhouse...? Please reply. Thanks. Here is a link that might be useful:

The most recently posted Long Island street view is from 2012! No proof they are still there after the 2 polar vortex winters. And the other recent winter that was very cold in New England but not as much down here. (2016 IIRC: well below 0F on Martha's Vineyard. Have no idea how LI fared) They often look out of place in typical residential settings but I think those twin Seattle trees suit the house and are well taken care of so I give them a pass! Good catch GG. I am actually wondering if the NW DC, Bethesda, and Baltimore trees survived this horrid summer...by far the most humid I can remember. We barely had any comfortable dewpoints throughout September, not until the last few days. USUALLY cold fronts start pushing in some crisp weather by the 2nd week of Sept. It was a constant steambath since May. And yes it is humid compared to the PNW, but constant dewpoints 70F or above are not normal at least up here. There's a reason you see at least a few old ironclad rhodies in the DC/Baltimore area, but none in the deep south. And other than the late June/early July drought/heatwave - just long enough to be a nuisance - incredible rainy spells, one after another. I'm lucky to have only lost a couple important rhodies to root rot. OTOH it was nice to not worry about watering the 6 or so new planted camellias in my garden. They are so thirsty in the first year!