Electricity, fans etc VERSUS all natural?

[daemondamian]

Hi folks,
I'm in the process of planning a GH that I hope to build in the spring [I'm in Australia so it's Autumn here right now].

My friend up in Queensland has 5 GH's all made of arc-mesh covered in green shadecloth- the benches inside are of the same arc-mesh. There are those whirly things on top with closable [by rope] vents, 'windows' on each side [that can be covered with roll down window flaps] and solarweave covering on two of them.

He doesn't have any electricity- ie fans etc at all- it's all natural venting air flow [he says roof height is critical] and he grows things extremely well- if not indeed perfectly!

On the otherhand I have been growing things in a little plastic covered, black pvc pipe kit GH with a big desk fan in there, a 150 Metal Halide watt in there as well as two 45 watt daylight compact fluorescents.

I think I have been doing ok so far. I just visted the GH of a member of my local orchid club. His greenhouse- pipe frame, covered with opaque/white polyflute [Polyflute is a one-piece process extruded sheet consisting of two flat skins connected by vertical ribs. Made from polypropylene co-polymer, it has physical durability and chemical resistance properties that make it ideal for a range of uses. It is UV stabilised.]. He has shadecloth over the polyflute roof.

Inside he has two circulating fans, an evaporative cooler and misting on thermostat/timers additional lighting in case he is up at 5am and wanting to do something when it's still dark out .

He has side window vents but doesn't use them- because they let out humidity...

My Queensland friend says you don't need electricity- is he right?

Which way is better and why?

[littlefrog]

No electricity is always better because it is cheaper and far more reliable. But, you have to have a properly designed greenhouse, or it won't work.

My greenhouse has electric vents, the roof opens up like a clamshell, and I have two large vents at each end. If the power goes out when it is hot, I hope the roof vent is already open (it will stay open). And I can prop open the side vents with a clay pot. But to avoid such circumstances I put in a battery backup system that should run the greenhouse for several days to a few weeks depending on the time of year.

[daemondamian]

A bit of both eh? My friend up north has those whirly gig things on the roof that spin around, drawing air out. He says they can be closed to trap warm air in but it has to be done manually..

So I think he has five each with 2 of those vents except one has three on it so that's about 11 vents that have to manually be shut at night or in cold weather

I think I can see the benefit to automation!

I have read that there are vent opener/closers that operate on temperature and hydraulics and don't need electrcity or batteries- they sound good to me

[manfred]

hi damian how did your move go?Dean ,I think you know him,has a fantastic setup I reckon you cudnt go wrong talking to him abt your GH
cheers Manfred

[daemondamian]

Originally Posted by manfred

hi damian how did your move go?Dean ,I think you know him,has a fantastic setup I reckon you cudnt go wrong talking to him abt your GH
cheers Manfred

Hi Manfred,
how's your arachnis going? I turfed mine out of my little hobby GH into a hanging basket with a bit of sphag & loose coconut fibre filling it and hung it on the fence.

To my amazement the stems are actually putting out new roots despite the cold Victoria Autum weather

We didn't end up moving and are probably going to stay for quite some time so yup I'm in the planning stage of a proper big GH which I hope to start building in Spring .