Hot air rises, so if you just remove the sides you'll get a pool of very hot air at the top on still sunny days. It would be better to vent out the apex, perhaps you can modify the split roof to include a full length louvre? You say that is your plan, you haven't done it though?

You don't need much area to vent well, a vent the size of the square to the right of the door would probably suffice.

How do your self watering pots work?

It looks good! I am halfway through installing the roof on mine.

I really like it good job ! If mine I would get shade material and one of the mist fans from Lowes .. and as recomended more venting . Gin

Hi Dave

Nice greenhouse!
What size is it? Looks approx 10x15' (?)
How did you attach the polycarbonate panels and what thickness are they?

Domeman

Hi and thanks :). Not sure why, but GW didn't email me the responses. Sorry for not getting back sooner.

Looking at my post I should have included more info. :). I did install auto louvers and put fans in the windows. The top half of the door is screen and the ridge is open, I planned to used this only from late March to November. Thoughts were the ridge vent could be left open, if I were to close all the door and windows I wouldn't have alot of convection. With the fans running and all the windows/doors open on an 80F day, it was 95F in the GH. So I was concerned about how well will veggie production be when it is in the 90's outside and 100F+ in there. Not sure how well a misting system will work, we get high humidity along with hot temps for weather here.

I wanted to grow squash and cuks in the containers, now I'm learning about pollination issues..lol. So I thought, the side panels are easy to remove, why not open it up for the summer (leaving the end walls on) and not worry about heat or pollination. It would be like an outdoor veggie container garden. Swap in some fresh plants around late July (will have plenty off veggies coming from the outside garden around that time). Put the sides back on in Sept and keep growing. Kind of like a roll-up sides on a hoophouse.

nathanhurst...so far I'm surprised how well the containers work (first year with them), they seem perfect for GH growing. Consistent waster and fertilizer, holds 2.5cf of potting mix and 4 gal of water. Proof will be in the production, I'm optimistic :). I'll include a link to a closer look at how I made them. I got the basic idea in the Container forum, this is just my variation. Any pics of your GH?

ginge...I'll look into shade material, but direct sunlight on the house is 8~ 9 hrs, was wondering if shade cloth would limit light to the sun loving plants like tomatoes.

domeman...the panels are attached with 2" stainless screws and 1" rubber backed washers. A larger hole around the screw for expansion. The polycarb is 8mm (5/16) thick twinwall.

Here is a link that might be useful: DIY self watering planter pics

Wishing for an edit button here..lol. domeman, the GH is 12x16. I have enough polycabonate panels to add another 6~8 feet to the length if I decide to do an addition.
Dave

Dave

As well as wall fans I put in additional fan action inside to increase circulation. I found it successful in lowering temperatures and some plants respond well to the air movement. I use the large ocscillating direction pedestal fan - these are very low cost.

Here is a closer look at the ridge vent.
Dave

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The roof vent does look a little narrow (round is the best shape), could you remove the bottom framing timber and use a smaller piece? The problem is that the air is sticking to the flyscreen and to the sides of the vent which restricts the flow considerably.

If that is not enough I would take off the center PC on the ends at the top and put flyscreen there, and maybe a luva.

Hehe, now I see how your planters work they're exactly the same as my homemade self watering pots, only I just use polystyrene broccoli boxes and some coarse gravel on the bottom (total cost, about 30 cents excluding potting mix). I thought you might have some clever way to top the water up automatically from the tap. (like autopot systems, e.g.).

No greenhouse photos, been too busy making it to put anything online :)

Nathan..I'd like to hear more about your broccoli boxes :). I'm going to run a 3/4 poly line around the GH and use some sprinkler splices and run a branch off to each box. Then connect the main line to a timer valve for topping off.

So instead of trying to cool the house with fans and more ventilation, what are the drawbacks with removing the PC off the sidewalls? Mid June to mid Sept? The fans and vents should hold me over until the weather gets mild enough to open it up.

The ridge vent is 9"W and 16' long. Thats not enough area?

it's not just area, but also friction. flyscreen adds a fair amount of friction to the process. If you can take the flyscreen off you would probably notice the difference. Still, 12ft^2 seems reasonable. do you have any intake vents?

What do you want to know about the broccoli boxes? they're just rectangular boxes made from polystyrene foam that you can get from a grocer. otherwise my design is much the same as yours, but I use gravel or pine bark instead of the eggcrate for drainage, and 40mm pvc pipe for the tube. I'd like to replace the pvc pipe, as it isn't great stuff.

So your fill mechanism is to just fill to overflowing each day. That will probably suffice in your situation. I'm still thinking about my tomato powered evaporative cooler, and I need a more reliable system for that.

"tomato powered evaporative cooler"??

There are two windows w/screens, screen door and two powered louvers. I have fans in the windows and louvers pulling air in. Figuring the cooler air coming in from both sides would help to push the hotter air out the roof vent.
Dave

According to ASHRAE (engineers who do cooling), a chminey like vent should move 16.6 * area * sqrt(height * different in temp between inside and outside) cubic foots per minute. So for your greenhouse I get 16.6*12ft^2*sqrt(8ft*10F) = 1780cfm which would be more than adequate. I can only think that the flyscreen is resisting the flow too much, unfortunately. You could improve flow with a whirlygig vent or a chimney, though neither are really suited to your design.

Do you have any thermal storage (water?) or shading?