It may be easier to create a false ceiling just for winter use, then you could benefit from the extra height in the summer ;)

How do you deal with the agonizing pain of waiting for 2' of snow to melt?
I know just how you feel.. i`m waiting for the pesky freezing temps to rise enough so i can lay some concrete :)

Thanks for the quick response. I have thought about that, but I would prefer something more permanent.

I am also considering replacing the 4mm polycarb on the ceiling with 16mm 5 wall polycarb that has an R3 value. This will decrease heat loss in the ceiling panels by 50%.

Banana-fun, you'll be sooorrryy! Esp. since your name is banana-fun, favorite forum 1 is Banana, favorite forum 2 is Banana. Will you be growing bananas?
What is 12 inches off the sides going to do? Will you have height for benches?
Insulate with a solar cover for the winter. In the summer you'll be better able to cool it with the added height.
I think you should add height not subtract it.
Ensete ventricosum Maurelli
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Musa Basjoo
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It really does stand tall. But, looking at my HFGH, I think it would be a huge amount of work, pain and effort for not much gain. You're right about the door problem...they are the same height as the side walls, so you'd have to cut them down in height too. That would be really complicated since both the top and bottom have to fit into a sliding track...I really am not sure how you'd do it.

If you scroll down to about the middle of this page in my blog, you'll see some pics showing the three horizontal braces we added (made out of EMT tubing) at ceiling height. If you do something similar, you end up with the start of a false ceiling framework. If you decided to try blocking off the peak in the winter, the braces might be helpful.

Cooling is my problem, so in the summer I'm very happy to have that extra foot at the top so some of the hot air can sit up there above my head. I also like having side walls that are tall enough for 3 shelves of plants (most of my plants are under a foot tall, no beautiful bananas for me!)

If I ever have to replace my roof panels due to sun deterioration, I'll sure consider replacing them with heavier polycarbonate, as you said (if I can afford it!)

Sorry, no advice about the agony of 2' of snow. We'd have mass panic down here! Riots! Hysteria! Madness! :-)

Thanks cactusfreak, love the pics! I can't wait until summer when my nanners look like that. I just spent the last 20 min giving my bananas in winter storage a good cleaning and pruning.

I will only be growing bananas in the greenhouse in spring to give them a head start. The greenhouses primary function will be growing cold hardy palms during winter. I intend only to heat the greenhouse to about 15-20F.

Decreasing the height by 12" (maybe more) will decrease volume and not make it look so large. I do not want the look of a large greenhouse to bother neighbours.

I have not decided on the height of the benches yet, maybe 34"ish.

I will installing climate contols in summer that will exhaust the GH when temperatures exceed 100F.

We did some calculations in here about four hundred years ago on how to reduce heat loss in a greenhouse when you don't need light all the way to the ground on all four sides.

Instead of chopping a foot off your greenhouse consider insulating the north wall, part or all of the north roof and maybe 2ft around the bottom of the west/south/east walls.

In spring the sun is low so you will not lose much light by insulating the above. However if you insulate to R3 or so you can cut your heating requirements by quite a lot.

""I do not want the look of a large greenhouse to bother neighbours."" Give them some bananas!!!!

:)

I think a pool cover would save more than cutting the height.
The added height makes it easier to cool.

I have a 10X12 HFGH and the door faces north and the long west side has 1 1/2"foam board insulation all the way to the top of the wall. I also have the north wall insulated and I put the foam board 4 feet up the east wall.

I used the good bubble insulation from Charles and put it on the roof east wall above the foam board and the back wall.
I used the bubble insulation on the doors and a 14MM pool cover on the roof.
My GH heats very easy and it has plenty of sun light the plants do really well in it.

I think most would say that you can not insulate the west wall to the top but all you do is cut out some of the late afternoon sun that overheats the Gh. I would never consider removing the foam board it works far to good like it is.
These things would be much easier to do than cutting the GH down and would be many times MORE effective at saving heat while keeping the better cooling for the warm days.

I have to chime in with everyone here and agree that you would probably be sorry if you tried to shorten the height of your GH.
There are just too many other ways to increase the insulation of the GH and altering the original structure would be complicated and messy.

You would be missing out on a lot of shelf space, opportunities to hang plants and the cooling effect of having that space for the heat to rise.
And we've all agreed that cooling the GH is just as difficult as heating it, even here in the more northern locations. I'm in Ontario also, halfway between London and Sarnia.
Yesterday, outside temps were in the mid 20's but with the sun out it was 105* in the GH until I went out and opened a door a few times. That is *with* an automatic window vent that is located in the ridge line of the roof. Imagine what the temps would be if I didn't have that extra 5 ft of overhead space for the heat to rise to!

My GH isn't a HF but is homebuilt and quite tall. I'm thankful for the extra space that allows me to have upper shelves (or very tall ones on the lower bench), hanging baskets and good air movement. The walls and north roof are insulated and in winter I use a clear solar pool cover over the whole building, with a hole cut to accomodate the roof vent. I ordered it in the States and drove over to pick it up from an American friends address.

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Ok, you guys win. I will not shorten the GH. I do intend to attach my current 6x8' GH to my new 10x12. I'm not quite sure how yet, but I willing to bet it will involve lots of silicon caulking and some aluminum flats.

chris_in_iowa,
I was planning on insulating the north wall and roof with foam insulation and sealing all the polycarb panels with window caulking that can easily be peeled away if neccessary.

wyndyacre,
Very nice GH thanks for sharing the pics. Is that GH 10x12? What temperature do you keep your GH at during winter?

Here's 2 HF's connected together to get an idea.
Rob's New Jersery Greenhouse:
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It could look like this:
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Or like the top two pictures:
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My GH is 10x16. I keep it around 50* at night with a oil filled space heater wired into a thermostat. It works just fine on all but the most windy, coldest storms. This winter I added another space heater set just a couple degrees cooler than the original as a backup and they both work together during the coldest nights.

I use my GH for growing cactus/succulents, storing my tropicals and for starting seeds and divisions of perennials for myself and my huge plant sale I have every spring. I started sowing seeds, sticking cuttings and potting up some divisions about 4 weeks ago.

OH MY GOD.... I lovvvveee the picsss. Barb

Hi Banana Fun,
IÂm looking at buying a 10X12 HFGH. From which store in Buffalo did you buy from, did you call first to see if there were any in stock. I live in the Toronto area.
Thanks
Lou

abruzzese,

I bought the GH at the 1459 NIAGARA FALLS BLVD location. I did not call to see if they were in stock, but it might be a good idea. If you are driving down I would cross at the peace bridge. There were 1 hour wait times at the rainbow and lewiston bridges, but no wait time at the peace bridge. The boulevard mall is only 2 minutes away from HF if you want to buy some clothes for 30% off.

PS. the 10x12' GH box is over 8' long and weighs about 160lb.

Another option banana_fun would be to dig a large 'hole' for the greenhouse and lower it's constructed height that way. You'd have to deal with drainage issues but maybe you're on a slight hill where it wouldn't be a problem to drain rain water away.

kittyl,

I thought of that, but as you mentioned, drainage would be an issue so that is not a possibility.