Micro-greenhouse with thermo-hydraulic window opener

I have been growing cactuses for many many years, but never had a regular big greenhouse. What is pity because living in quite high latitude (48 grades) the effective and usable growth period for cacti is quite short. No more than 4 months in outdoor conditions. Peoples who have greenhouses, ideally with heating, can extend this time by two good months at least.

So I opted for this compromise:

A polycarbonate 1x1 m sized mini greenhouse for about 90 EURO. Photo taken in the morning when still in shadow, and still closed :)

Greenhouse of this size can easily cook your plants if closed in direct sunlight for 10 hours and I am not there to "babysit" it so some king of automatic opening is a must. And not too expensive of course.

So here come thermal based automatic window openers.

To make the long story short: there are two types of openers - as available on Amazon.

Wrong one

First I got this one - and it cannot be fitted in small greenhouse anyhow, so I was left without automatic opener. But not giving up I found another one browsing internet and mainly Amazon webpages.

Right one (almost fitting)

Here it is in work:

It fits only almost so some 'duck-tape' adjustments were needed, you can easily see yourselves on the above picture.

Adjusting target temperature

What I noticed was that the opener is too eager to open the window and keeps the temperature too low, so I had to drill extra hole in the axis of the shaft. It is less eager to open window now, so it is OK. 

So far after about one month cacti looks nice and growing and going to flower. I am going to find out if summer temperatures that can reach here about 35-37 centigrade will not be too high even if with the opener.