Greenhouse back garden - probably best DIY project

Calahonda52

Wonderful project: thank you for posting all the detail.

A few questions:
How does the heat recovery work:
You take the hot air from the top of GH and pump it through the perforated pipes into the stones and it also comes up through the pipes around the edge?
How do you change the air once a day?

recedite

Its not going through the stones, just the pipes. With those 100mm pipes and that many of them, there would be quite a large volume of air stored in the pipe.
If OP is still looking at automation options. I suggest maybe see how long it takes to "flush" the pipes (after which time the air coming out is closer to the same temp as the air coming in.) Maybe 10 minutes or so.
Then set up a timer on the fan to operate for that 10 mins or so every hour (or half hour) during the sunshine period. To charge the soil.

Add a thermostat in series too, so it only kicks in when the air temperature has reached a certain point, say 20 degrees in summer, or less in winter.


Then do a time control for the coldest part of the night, to take the heat back from the ground and heat the air in the greenhouse. I think this would have to be a second timeswitch, so the power goes straight to the fan from it without going through the thermostat.

rolion

So,there are few mechanisms independent and working togetehr.
Very important that the plants are not exposed to shift changes and extreme values... i lost a lots last year due to temps reaching over 40 for hours,for days !

For cold days,i have a mini MHRV unit fitted that takes out the CO2 air from inside and warms the fresh oxygeneted air from outisde,then spreads on 180 degrees at the roof level.
This is to keep the humidity and air at a certain levels when is cold outside.

The geothermal system,is a closed system.We know that some plants loves CO2 and they grow betetr with it.Also,they are overreacting when changes abrupt in temperatures.So the two big fans takes the hot air from top and moves it through pipes inside the soil and then force it in many directions,inside,at ground level,under the plants leefs or at their level.The system brings about 3 positive degrees in the cold and over 10 degrees when is too hot. Is not the most efficient system...i seen after i built mine a dual piping one,with major pipes at 150cm and other smaller size at 30cm .Deeper for constant heat,higher better for plant roots. Next time...

I have 6 (six) cooling fans that can be programmed to change speed and direction. Can go slow or fast. Can bring cold air inside or extract hot air outside.There are DC motors from car radiator's fans. As well, the outside extractor holes can be covered or left open,with a piece of mdf timber,controlled ( i truly hope) with a linear actuator,to be ordered online.Now,i just pull up or down,as needed.mostly down as high temperatures.

i have a home dehumidifier that work smostly at night time,in the morning,when higher values are being recored ( plants sweat due to temperatures changes).

Also,i have in plan a black-out foil that will open or close,rolling under the acrylic roof,covering sections of the ground against high solar light / heat /radiation.Roof being acrylic,it already disperses the sun rays.

Working curently to tidy up the controllers and the wires inside the GH. Just delayed and plants / seeds went in already.
I have SONOF controllers and i ordered another temperature logging system for graphs and historical analysis,to see reaction to changes in fans. With SONOF, you can create timers,actions based on events and / or scenes.Very handy !

Never ending story,work,improving,playing,testing,enjoying,eating,talking to my lovely plants...

recedite

Its a lot of fans alright.
Do you think the dehumidifier is needed? Plants usually like a bit of humidity.

Looks like a fire waiting to happen.

rolion

recedite wrote: »

Its a lot of fans alright.
Do you think the dehumidifier is needed? Plants usually like a bit of humidity.

Yes,you are right.
Last year,i had only the geofans and ... the doors.
I lost a lot due to heat and humidity.
Summer time,over 40 degrees.
And,most important,when the big plants are "big" i still need to get the air flowing under their leafs / ground levels,at the ground level. Otherwise,is going to be a heaven for diseases...

For tomato and cucumber,there is a plague that makes the leafs going like white powder,that bacteria thrives in heat and humidity.
I empty twice a week that dehumnidif water container... and in cold seasons keeps the algeas away too.

BrownFinger wrote: »

Looks like a fire waiting to happen.

Thanks, thats why i have the black metalic cabinet on the floor,waiting for a free Saturday to fit and tidy and label all in there.

recedite

Is that a tomato seedling growing out of an upside down plastic bottle suspended from the ceiling?
Not that there is anything wrong with that, I was just wondering.
You'll be able to stand underneath it and just nibble the little cherry tomatoes off the plant

recedite

Oh and I see a grape vine too. Even better for nibbling.

rolion

Well spotted my friend ! Nice...

Grapes runnign too wild in the 3rd year as i want to give it a form / length around the greenhouse inside / roof.
Already blossoming and few fruit shots are happy.
Every week i need to spray it with washing up liquid and water, lots of flies and insects around attacking the stem.






Tomatoes,i tried something new this time.
Last year,the ones inside riped faster but at a cost of the taste while the outside ones way longer and slower but with a deeper sweety taste.
So,this year i want to give it a try to both,in the bottle hanging and see if the gravity does any difference.
And easy to feed and water too.
Is amazing how quick they turned against the earth force...

recedite

Its an interesting idea alright. Tomatoes don't seem to need much soil.

At the end of the summer when you pull up a big plant its surprising how small the root ball is. Even when the plant has plenty of room, it doesn't seem to expand the roots out to use it.
Use some kind of liquid feed mixed in with the water later on, and they should be grand.