Eden shading...help needed please....

Hi Everyone, having just put up my new greenhouse I have already discovered I need to shade the sun coming in! Please can anyone help, I have googled Eden accessories to see if they do shading for my model which is the "Birdlip", I have to say I am absolutely delighted with it! thanks for reading, happy gardening

 

Grannies old net curtains!

 

Sacrificing upto 50% of the available light to control temperature never made any sense to me.

 

It's a bit late if you've already got the greenhouse, but I think the main thing is to have adequate ventilation, preferably with automatic openers. Saving money on that so you need to retrofit shading later on is a false economy. As Hex_2011 says, shading cuts out the light your plants need to grow, and unless you're going to be around all day to open/close blinds as required then you're going to have shading in place and blocking light at times when it's not needed (e.g. mornings, overcast days), when your plants would benefit from all the heat & light they can get.

 

Ventilation helps but its limited by the outside temperature and how much air you can move. I can keep the greenhouse temperature in check without too much trouble. Preventing direct sun from scorching plants and creating shade without using any fixed shading isnt as difficult as it sounds

 

What do you do to achieve this?...

 

Nature has all the answers, i`ve used the ground under the greenhouse to control the temperature since 2009. I did a test last year during that hot spell (32C), sealed up the greenhouse in full sun and waited for it to max out to a very toasty 140F. Still sealed up and in full sun it took a tad over 12 minutes to drop to 68F which was the average temperature of the ground at that time.
Shading without using physical shading involves using dry fog (1-30 microns) to create a cloud in the greenhouse.The density can range from a light haze to a complete whiteout which takes about 4 minutes for 900 cubic feet. The whiteout level raises RH% by about 15%. To maintain the "shading" you just need to topup the fog as it hangs for ages.
Here`s an idea of what the fog looks like, its normally used for dust suppression. A single nozzle would take about a minute to whiteout the largest Eden Birdlip model which has a volume around 214 cubic feet.

 

That sounds impressive and if as you say it can work in a typical 8x6 greenhouse it could solve a lot of folks over heating problems.

However can you give more practical details of how you have done this and what equipment /cost is needed to achieve it ?

Also in summer, as you say, how often do you have to keep refilling the greenhouse with the haze ?

My only negative thoughts about it would be that when using it, there is no ventilation, so does this have an impact on the plants ability to breathe/ gas exchange ?

 

My ventilation and cooling are seperate, i mainly use passive venting at night or occasionally in the day to replace co2. The cooling consists of a matrix of perforated drainage tubing buried 4ft deep in the clay soil under the greenhouse. A variable speed duct fan (155w) moves all the greenhouse air underground upto 60x an hour. It takes less than half a second to scrub 30F off the air inside the tubing, the higher the RH% the more heat is transferred.Install cost was around £150 all told if memory serves so thats £18.75 per year so far.
The fog is generated by a twin fluid ultrasonic air atomising nozzle, which uses compressed air and water. The water is initially sheered into droplets inside the nozzle and as they exit they impinge on a passive resonator tube (which vibrates at ultrasonic frequencies like a tuning fork) further reducing the droplet size. I use reverse osmosis water as it leaves no residue but the nozzle can turn most liquids into fog, including neat neem oil.