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

Yikes !!

I though my old orchid set up was complicated, but that sounds quiet amazing !

What size greenhouse do you have and are you growing some very specialized plants ?

Though very interesting, think for most folk its not a practicable or affordable system, but would love to see some pictures of it in action and during your build stage if you took some pics.

 

Easy peasy.....most garden centres sell green shading net. it`s not that expensive, lasts for ever and it works. You can use it inside or out of the greenhouse.

 

Given that nowadays you can control your heating from your phone.. that would`ve been met with similar sceptism as my greenhouse in 2008, switches were "in", now switches seem to be "out", but basic greenhouse design will probably never change.
Home build greenhouse.

 

Its a good looking greenhouse, would have been nice to see a finished pic of it with benches /plants etc.

Bit surprised you have not made a dedicated build thread of it (?) , would have been very interesting to follow.

Hi Tech, it all comes and goes, just on the news today, that paper books are making a comeback as E reader sales drop.
I've built and programmed SMS remote switches etc, ok for receiving warning messages but generally still prefer to operate the physical switches etc, smart phones just too small/ tiresome to read for me these days.

One point I cannot quite see, you say you use perforated hose, ( land drain 80mm type ?) laid 4 ft deep, but how many meters did you use and , importantly, what stops the hose from filling up with ground water ?
Does it also operate in reverse to give back heat during winter ?


EDIT - Sorry to TravelBug, not meaning to hijack your thread ... I used this last year on my polycarb glazing, found it went on easy and came off ok at the end of the season.
Summer Cloud Greenhouse Shading | Vitax

 

Yup, can do the Rick Wakemans grump old man bit too,, but also do like some of the newer tech, keeps the grey matter going !

Think Hex is a bit reticent about his greenhouse and cooling projects as its rather different from the conventional and am sure some will find it ott, but equally sure as many more will be interested to see what different methods can achieve.

 

I am currently preparing the site for my new greenhouse and Hex_2011's post has got me thinking. My problem is that I cannot get 4ft down as I hit rock at between 2 and 3ft.
In theory the clay will be warmed in the daytime and then give up its heat to the air at night. Even in winter the clay 4ft down should be several degrees above freezing so the air coming out will be above freezing even without any daytime warming. The overall effect will be to smooth out the extremes of temperature.

 

I dont comsider it to be high tech, it doesnt involve heatpumps or any of that malarky. The plants generate the water vapour through transpiration which is their natural method of cooling. The air goes underground, drops to dewpoint and the water condenses out, releasing the heat used to evaporate it in first place (980btu/lb). The plants get the water back and the air returns cooler and drier. The only tech is plastic tube,a fan with speed comtroller hooked up to a differential thermostat.(compares the difference between air and soil temperature not the actual temperatue)
It works for cooling and heating, keeps the gh above freezing in the winter. Water in the tubing isnt an issue nor is mold as most people think.
Using solar panels to generate compressed air is good but nature provided a better method in the USA in 1910. The Ragged Chutes air plant (Trompe) produced a constant 40,000cfm at 125psi for mines until the 1970`s with just falling water (no moving parts). The compressed air was clean, cool and free. You dont need high tech, just a big river than runs downhill A longish vid but interesting to watch.

 

They do but not quick enough to be useful.What you need is 200ft waterfall or a 200ft deep trench next to a river

 

Looked into this a bit and found these two articles Greenhouse Heatsink Connection Diagram | REUK.co.uk
Solar Greenhouse Heat Sink | REUK.co.uk

 

Mr strawbridge`s design isnt effective, physics/thermodynamics dont seem to be his strong point The performance of a system is related to how long the "entire" greenhouse air volume spends underground. This shouldnt be confused with how long the air spends underground.
Conventional wisdom suggests using long tubes and low airflow rates so the air stays underground for longer. What you need is the exact opposite. Long tubes create resistance which reduces airflow. The fan also has to work harder which increases power consumption.
The air will drop to the soil temperature in the first few feet, its very difficult to get the outlet air temperature to rise above the soil temperature unless you have considerable airflow, typically not less than the equivalent of 20 greenhouse volumes per hour with shorter tube lengths.
If the outlet air temperature is always the same as the soil temperature, you dont have enough airflow to utilise the full cooling capacity of the tubing and the efficiency will be low.
As an example, the extreme temperature test moved 1.26kw of heat from the air to the soil in around 12 minutes using 31w of electrical power. This figure relates to the energy difference in the greenhouse air between the start and finish points but doesnt account for any additional heat gained during the 12 minutes as the greenhouse remained sealed and in full sun throughout.
This represents a short term, one off COP of 40, but 10-20 is typical with normal (80F-90F) temperatures in cooling mode.