Greenhouse

I have a few sets of used sliding glass doors I plan to use for a greenhouse . I originally planned to use them double pane like they are but read somewhere that the panes should be separated & used as single pane glass if using for a greenhouse .
Anyone know which way they should be used & why ? TIA

[||Downhome||]

I say depends on the weather you expect... here I'd leave them double pane.

Edited to add, they can be a pain to get to part sometimes also.

[Paumon]

If you live in a location that gets very cold from the autumn to spring it's advisable to leave them as double panes for the added insulation. If you live in a location that is generally very hot and humid from spring to autumn and doesn't get very cold in winter it's advisable to have single panes. If prolonged outdoor humidity or rain is a problem in hot climates then with double panes there's an increased risk of moisture getting in and remaining collected as steam between the 2 panes and causing growth of algae and mold between the 2 panes of glass. There's also the higher risk of retained moisture between the glass panes causing rot and other structural damage to a wooden greenhouse frame.

[Callieslamb]

I think if you're using them as the bottom part of the greenhouse, it's great to just leave them as they are. If you want to use them on the roof, it might be easier to separate them. That would be a lot of weight to hold up on a roof. I've seen a patio roof made with them, but they were used single-paned.

[Wolf mom]

I hope they are "old glass". By that i mean glass that has not been treated with any type of film as that inhibits the sunlight and heat needed for plants to grow. I'd really check out the doors if they're double paned. What is needed, is for your future greenhouse to be facing true south.

There are lots of ways to capture heat in in the winter from a sink hole to black painted water barrels. All it requires is googling solar green houses and creative work.

[7thswan]

I used them for the walls of one of my greenhouses and they worked just fine.

[ronbre]

my purchased greenhouse I've had for over 20 years is double corrugated polycarbonate, always use double if you can. I have used salvage doors to enclse a back porch and have more in storage to enclose my east door this spring

[KIT.S]

If they're relatively recently made, they may have some kind of gas between the panes that retards sunshine and kind of negates the greenhouse effect you're looking for. (Found that out in Oregon after using inexpensive new big windows for another greenhouse)

In Alaska we had a greenhouse built onto the side of the house made all of (older) double-pane sliding doors. The walls were great, but the slanted roof always leaked a little. There was a rim at the eave line that we could never get completely water proof, and when the ice built up at the eaves, it always leaked. I don't know what the solution would have been, but maybe something different on the roof, or even a layer of those wiggly fiberglass panels above the sealed sliding doors, so the rain/snow didn't get to the glass.

It was a very successful greenhouse, though - the door into the house itself was also a sliding door, and we just left it open and put more wood on the fire to heat the greenhouse along with the house.
Kit

[TnAndy]

If you use them doubled, the seals will likely fail ( or may already have ), and you will collect moisture between the panes, reducing your light into the greenhouse.

Also, really older panels did NOT use tempered glass, so if they break, you'll have large hunks of glass that could rain down on you. Tempered glass is tougher to break, but when it does, all you get are a million little tiny pieces.

Newer panels may have LowE glass, either as a coating added to the glass, or made into the glass when manufactured. LowE glass is designed to reflect heat/light away from the glass to lower energy transfer, making windows more energy efficient. You can sometimes see a slight purple sheen to the glass when viewed from a side angle, but not always.

Argon gas is also used sometimes between the panels, but has no effect on light transfer...just heat transfer....and it leaks out of the seals anyway after a year or two, so it's not an issue. Argon is just a gimmick used by the window industry to temporarily gain a better energy rating for their windows, and to make theirs sound "high tech".

Is the glass marked in any way so I can tell if it's tempered or not ?

[TnAndy]

Not the glass usually, but sometimes the aluminum spacer between them is stamped with a date code so they could tell for warranty purposes when the unit was assembled. IF you can find that, and IF is is about 1980 onward, it should be tempered glass.