Greenhouse glass - a blast from the past

Last week, I tried finding windows for the greenhouse in the demolition yard, and on Craigslist, but - no luck. Craigslist has lots of windows, but not the kind that would work in a greenhouse.

So, this morning Dusky Footed Wood Rat and I laid out the footprint of the greenhouse with scraps of lumber, decided that 10X14 feels like a goodly size, and headed into town to explore our options.

At The Home Depot in Soquel, we found some wood frame doors with glass panels that actually looked promising, for around $170 each.

The frames were about three inches wide, though-- Hm. Well, it would be pretty good. We were almost convinced. We almost bought them.

But we decided instead to go to Lighthouse Windows a few miles north in Santa Cruz, and talk to the friendly people there before making a decision. When Rat replaced all our misted-up dual-pane windows, that's where we bought the replacements. They're a local company and we like to shop local when we can.

Guy at Lighthouse Windows got right into the spirit of the project. It would be easy, he said, for Rat to just frame custom cut glass. At around $4.65 a square foot, it worked out to be about half the price of The Home Depot door solution, and it would be much prettier without that thick frame.

Or - even cheaper - he could sell us the panes of glass that go into standard door frames. They are dual pane low-E glass, though. Would that be a problem for a greenhouse?

We did what anyone with a question does: got on his computer and Googled. No problemo - low-E glass is actually good for greenhouses (you can see more details below).

Guy and Rat got into a discussion about using turnbuckles to prevent sagging - and Guy invited us outside look at the cool turnbuckles under the old Santa Cruz to Roaring Camp holiday train, which was parked just behind his fence.

I couldn't believe my eyes. Look what was propped up against the fence:

"Wow! Wow! Look at this door! This door is great! Wouldn't that look cool on the greenhouse?" I enthused.

Guy grinned. "You can take it, if you want it. It is a cool old door."

"And what about all this other stuff - Look, more doors, and even windows!"

"These have real character, don't they? Take what you want - it's all going to the dump, except a few things I'm keeping for myself. "

"Really? Really?" I squeaked. I was one tickled-pink mouse. Rat gave his assent, from the woodworker's point of view, and Guy was just delighted at the whole idea.

I was doubly impressed by his generosity as he helped us load up the truck because every door we loaded was a sale he wasn't making.

Five regular size doors, two beautiful narrow doors (you can see them clearly below), and four windows, all wood framed, some from houses nearly a hundred years old, with "wavy" glass.

So having gone around the mouse wheel a good few times regarding the greenhouse covering, we have ended up with super-cool, traditional-looking recycled old doors with that traditional look I really wanted all along but didn't think I would ever be lucky enough to find.

We still have the roof to consider, of course, and you can be sure we'll be going back to Lighthouse with that business.


Low-E Glass
It turns out that glass with low-E coating is actually better for greenhouses than non-coated glass. I did a bit more follow up at home and here are a few links and bits of info for your delectation. (If you want more technical details, just google "low-E glass.")

http://www.hobby-greenhouse.com is a Canadian company with attractive kits, and good info on their site. They have this to say about glass:

Double-walled tempered glass reduces [heat loss] by about one third. Low-emissive, or low-E, coating, is another option; it reduces heat loss without a corresponding loss of light. In addition to being energy efficient, low-e glass reduces condensation, partially blocks ultraviolet rays, and makes the inside glass warmer to the touch.

Florian Greenhouse is also a big fan of low-E: "Research has shown that the stability offered by Low-e coated glass enhances the growth for a wide variety of plants. "

I also read on a Google Answers page that "when the sun's elevation is high in the summer the heat will be reflected back and not enter your home. In the winter when the sun's elevation is low the heat will be absorbed." But I don't know on what basis that statement is made.

This invaluable nugget about which side of the dual pane window the low-E coating should go on, comes from a www.energysavers.gov page:

If the windows are designed to provide heat energy in the winter and keep heat inside the house (typical of cold climates), the Low-E coating should be applied to the inside pane of glass.

Yup, greenhouses are designed to provide heat energy in the winter alrighty! Good to know: coating on the inside.