New Greenhouse and Heat sink....

[lmayhow]

I am so excited, he's budget but hey it was that or don't have one so we are happy happy. Brought in November it has been a slow process to build what with shift work, children and family visiting (my Dad did help us a little) but ta dah!!!!! Currently he is being held down by ropes and bricks but we will fix him permanently in the next week or so. Cant wait to grow tomatoes', peppers, cucumbers blah blah, blah. Husband also brought me a heated propagator for xmas so its full steam ahead next season what with the garden and allotment should be easier work with seeds in greenhouse?

The last job when its warmer is the heat sink we have read about, anyone managed this with effect before? Dig hole in GH fill with plastic bottles, rubble, polystyrene with network of perforated pipework. Then leading up to above ground with a fan, leisure battery and solar panel. We have read this out of a Dick Strawbridge book about self sufficiency. Was hoping to hear from someone who had tried and seen how there effort worked out.

[Snadger]

This will enlighten people.

Solar Greenhouse Heat Sink | REUK.co.uk

Good way to get rid of the broken glass and scrap metal on my plot!

[happyhumph]

Looks interesting - OH v interested in doing to ours retrospectively.

[JusPotterinTim]

In my mini wood-polycarbonate greenhouse (about 1 metre high, 80cm wide and 60cm deep) I used 2 litre drinks bottles at the bottom, and filled them with water, then added food dye to turn the water black (to try and absorb more heat). I needed about 50 litres for the water mass to make any real effect on the night time temperatures. I have ended up with about 65 litres in there, and it made a degree or two of difference at night in autumn when I was monitoring the temperatures. When it gets close to freezing though I think the effect is stronger, due to the crystallisation energy of ice, i.e. it takes a lot of energy to be removed from water to freeze it so it acts as a buffer when the environment is on the cusp of freezing temperatures.

In a larger structure such as your greenhouse you have proportionally less surface area compared to the volume of air so you would need proportionally less volume of heat absorbing matter I think.

[jackarmy]

Had to comment just about that ^^^^^^^^^^
loving that username Tim

[JusPotterinTim]

Thanks jackarmy, I do exactly what it says on the tin. This week I have spent a few hours reinforcing a new blowaway greenhouse with clear tape, stapled the zip with about 200 staples to reinforce it, added gaffer tape to seal the bottom to keep the cold out, and put coat hangers on the top to make it tent up and let the rain run off. I'm even considering adding a greenhouse vent opener to the door of my blowaway.

I do love pottering!

[Baldy]

Some breeze blocks to anchor it... ;-)

[JusPotterinTim]

Cable ties, forgot to mention that step... ;-)