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Lakewood, Colorado

I thought I saw in someone's diary or somewhere that a grower built a small framed greenhouse with roof vents that have actuators that open when it gets too hot. Now I can't find it.

I see commercial websites where you can buy an entire kit, but I would rather build one myself. I really need the vents since I am not home all day and my helper doesn't necessarily care as much as I do. In colorado, when the sun comes out on a cloudy day, the temp skyrockets to over 100 degrees really fast.

5/21/2014 2:18:18 PM

Roy, Washington

Harbor Freight has cheapest solar vent openers I've seen -

http://www.harborfreight.com/greenhouse-window-vent-opener-92192.html

I haven't used these so I can't vouch for them but similar (more expensive) ones in my wife's greenhouse work very well.

Todd

5/21/2014 3:10:54 PM

Farming- a bunch of catastrophies that result in a lifestyle

This works pretty good:
Picture a window (the kind that hinge open and closed like sash windows that you can wash from inside)
Picture that window 'pinned' in the middle, slightly off center, instead of at the bottom like normal. If that window was mounted in the roof, it would 'fall open' all the time because one side would be heavier with it 'pinned' off center.
Find 2 old Governor springs with the long hook things on either end.
Find two of those big straws like Mc donalds gives you for milk shakes.
Put one governor spring in each straw.
Fill straw with liquid wax and let solidify.
Hook window closed with the waxed encased springs.
The wax melts at about 87 degrees in the greenhouse, the spring isn't strong enough to keep the window weight up, and the window falls open.
I had a box of those bricks of wax ladies us for canning. I'd fill the straws at night, hang windows with them before I left for work in the morning.

5/21/2014 4:09:35 PM

Little-TON - Colorado

Brilliant LB...ThankZ

5/21/2014 5:19:24 PM

East Jordan, MI

Don't waste your money on the Harbor Freight ones. They will fail and cook your plant (ask me how I know).

This is what we use now. Have had them for 3 years and they still are like new.
http://www.groworganic.com/automatic-vent-opener.html

5/21/2014 6:09:02 PM

East Jordan, MI

Here are the plans for the cold frames I made. If I had to do it again, I'd make them about 18 inches taller. The ones we have are great for baby plants, but when the plant gets some bigger leaves, they are too close to the plastic and a hot day will burn them.

http://cgpgrowers.blogspot.com/p/coldframes-wauto-openers.html

5/21/2014 6:21:38 PM

Anchorage Alaska

these work great .. for

http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=153495

5/21/2014 9:28:24 PM

Lloydminster/AB

I use those ones that are at grow organics.com. Get a couple of spare cylinders because they fail once in awhile(the rod bent a little on a windy day, just wouldn't close smooth after that) though most of mine have lasted 5 years or more. I have a cold frame that is about 5x7. The open window is about 4x7 so I am pushing the limit for weight. I like the way they disconnect quickly to open and close the frame.

5/21/2014 11:23:19 PM

Central Illinois

I would not rely on one opener in each greenhouse, temps can still get over one hundred easily, they will still help on those days you forget or cant ventilate manually.

Size would matter, a small greenhouse with a big window would cool off better than a large greenhouse

5/22/2014 8:07:56 AM

Little-TON - Colorado

Erik make sure they have emergency release for hail stormZ

5/22/2014 9:47:05 AM

Lakewood, Colorado

Thanks Cecil and everyone for all the help. This is a project for next year. Now on to the hail structure to cover the entire patch. That's what I will be working on this weekend.

5/22/2014 11:44:45 AM

Lakewood, Colorado

No more naked growing like Wizzy!

5/22/2014 11:45:24 AM