Arlons Blog: Propagating Cycas revoluta "aurea" ..SUCCESS !

[Julia]

Tear down the bubble wrap immediately, the insulation is a wonderful colour. I was thinking how gorgeous the plants looked in front of it and then you only went and covered it Seriously top job though, secretly you are slightly OCD, everything you do is so neat and ordered, not like a bloke at all. Hope it makes a difference to your greenhouse Arlon, hopefully you'll have a terrible winter just to test it out, only in Wales though

I'm loving the pink too

[flounder]

Its too girly. Then again I suppose you've got those soft, manicured, builders hands

[Arlon Tishmarsh]

Its too girly. Then again I suppose you've got those soft, manicured, builders hands

The Gok Wan of building

[Arlon Tishmarsh]

Blog on...........

Next to bubble wrap was the glass roof. Anyone i've ever known do this has always put the bubble facing the glass. I've never understood why ,as in construction terms it causes "cold bridging" and in my humble opinion reduces the effectiveness of the insulation. So, where there are glass area's, all my bubble will face inwards away from the glass.

Having bought the 1500mm wide wrap mean't that i could do each side of the glass roof in one continuous 21ft by 5ft length of wrap, so no joins, no taped joints etc..........



then out with the benches down the other end of the greenhouse...........



insulate and back in with the benches...........



then the other half of the roof and 21 feet of front glass panels..........







just the roof apex's left and a few odds 'n' sods, tape a few joints and its about done. A fiddly job but worth it i think if it lasts a couple of years.

I'm toying with the idea of making a couple of solar collectors out of some glass shower doors, as well as an "above ground" heat sink with a heat collector made from old black soil pipe at the ridge of the greenhouse.....perhaps next year

[Simba]

Its all coming along a treat Arlon, and that Moorei of yours is looking in great condition....

EDIT: I posted the wrong thumb icon, hope nobody noticed....LOL

[Mr List]

wouldn't having the bubbles against the glass trap more air in the gaps between the bubbles?

like making extra bubbles?

[Arlon Tishmarsh]

wouldn't having the bubbles against the glass trap more air in the gaps between the bubbles?

like making extra bubbles?

Having worked in construction for what seems like a zillion years , we always do the utmost to avoid "cold bridging". Having the bubbles touching the outside glass would allow the transfer of cold temps into and heat out of the greenhouse more quickly. A bit like having bubble wrap inside the two panes of class in a double glazed window. By putting the bubble facing away from the glass and keeping it taut, the result is two surfaces that don't touch and therefore reduces the transference of heat / cold.

Thats my theory anyway

[Arlon Tishmarsh]

and that Moorei of yours is looking in great condition....

Its not put on as much growth this year Kev. Hopefully a repot in the spring ready for next season will get it motoring again.

[Bob]

Very nice job Mark!!

[Arlon Tishmarsh]

Thanks Bob

[Kristen]

Thats my theory anyway

"feels right" to me too.

It raises the question in my mind though about whether the bubblewrap should be attached to the frame, or can be suspended inside the greenhouse - like pitching a freestanding tent inside the greenhouse.

Run a wire below the Ridge and Eaves and "drape" the bubblewrap over it. It will have no contact with the glass at all, but it will leave a large air-mass between bubblewrap and glass, which will be free to move, and maybe that movement will reduce the effectiveness of the insulation benefit? (That's the bit I'm headscratching on )

If this "tent" approach would work efficiently then the "Ridge" support could be reduced to the lowest level that would allow working inside the greenhouse, which would reduce the volume of air needing heating

Creating an opening in the "tent roof" to connect with the roof-vents would be an issue.

(Commercial greenhouses use a "thermal curtain" which is drawn horizontally above the plants to create a smaller-volume of air that has to be heated, but that curtain is opened during the day / when ventilation is needed)

[Yorkshire Kris]

Top job. I wish I had half your practical knowhow.

[Julia]

I wish my looked as neat as yours
Did you use spacers on your GH clips? (Sorry if you have already said)
I did. I read something on here about condensation. But I found those green spacers fiddly to use, mine kept twisting out the frame!! I nearly chucked them!!!

[Arlon Tishmarsh]

Top job. I wish I had half your practical knowhow.

I wish i did as well

............ like pitching a freestanding tent inside the greenhouse...........

Yep, i understand what you mean Kristen, I just wonder would the added expense and time in doing it would justify any gains for peeps like us working on a small scale.
As far as cold bridging is concerned, by turning the bubble away from the glass it reduces the amount of cold / heat transference by an extremely large margin. At the moment the only contact is the thin ali frames of the greenhouse. If the "large" bubble was toward the glass, practically every bubble would press against it and would probably result in a figure of approx 70 / 80% cold bridging, which imo reduces the effectiveness of the bubble insulation dramatically.

Did you use spacers on your GH clips?
I read something on here about condensation.

Julia, I didn't use spacers at all. Just the ordinary fixings are fiddly enough. If i had hair i'd have pulled it out by now.......

Condensation was another reason i turned the bubble away from the glass. There's always going to be air movement between the underside of the glass and the bubble wrap . With the bubble turned away from the glass it will allow the air to move more freely, keeping it gently ventilated and thus reduce or hopefully negate any condensation. I would have thought with the bubble pressed to the glass it would reduce the trickle ventilation effect which imo would increase the risk of condensation between the glass and bubble wrap............

[tropicalwon]

Love the greenhouse Built better then a well known house builder, which rhymes with claret...

Very well insulated!