[EMAIL PROTECTED] wrote: > Message: 7 > >Date: Tue, 29 Jul 2008 09:39:29 -0400 >From: [EMAIL PROTECTED] >Subject: Re: [OGD] Orchids Digest, Vol 10, Issue 216 >To: orchids@orchidguide.com >Message-ID: <[EMAIL PROTECTED]> >Content-Type: text/plain; charset="us-ascii" > > > Replacing the polycarbonate on the roof of a greenhouse with 5 or 7-wall > plycarb. would insulate the greenhouse better and save on heating costs. > > Not necessarily a good idea in areas with heavy snowfall. My triple-wall glazing prevents snow from melting at any noticeable rate. I had to make a rake, get out in the snow, and up onto a ladder, to 'rake' off the snow to allow light to enter and, during our large snowfalls this past winter, out of fear the two feet of snow would be too much weight. Here in central Ohio, snow can sit for a month or longer before temps rise enough to appreciably melt it. No light getting into the GH for that period of time would have very negative consequences. I had planned to line the interior of the GH with sheet plastic this winter, but now will definitely not do the roof.
> >2.The area above the sidewalls is space that does not need to be heated, at >night. So, retractable, thermal, shades trap heated air where it is needed, in >the area of the greenhouse where the plants are. > I have friends who do this and say it makes a big difference. Theirs sits on suspended wire and pipes and is simply manually pulled across them with pole 'handles' at the end of the day. Unfortunately, I can't use this as I have a lean-to style GH with plants all the way up to the top (five levels of shelves against the wall). Many of your ideas are good ones and hopefullly others here will come up with additional ways to help hold costs down. One I've toyed with is somehow dividing the GH to allow part of it containing cooler/cold growing plants (disas, laelias, lycastes, paphs, trichopilias, masdevallias, etc.) to use less heat, reserving that for the vanda/bulbo/catasetum/phal area instead. A friend heats his GH only to 40F in the winter and his disas love it. He also had no trouble with his parvi paphs, which often set bud at that time. Tennis _______________________________________________ the OrchidGuide Digest (OGD) orchids@orchidguide.com http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com