/ Register

Welcome to OrchidsForum.com. We are a friendly online community for Orchid Growers all over the world. If you haven't joined yet we invite you to register and join our community. Hope to see you on our forums!

Greenhouse window quality

Discussion in 'Growing Areas' started by Miska, Nov 24, 2009.

  1. Nov 24, 2009 #1
    Miska

    Miska New Member

    Messages:
    3
    Likes Received:
    0
    Location:
    Norway
    I am building a 125 sq.ft. greenhouse connected to my house. The main object is to grow orchids (mainly phals & cattleyas). I live in Norway, near the coast, where yearly temperatures range from about 15-80 F. We have a minimum of 5 hours daylight in winter (no sunlight on the house) and 18 hours daylight in summer (16 hours of sunlight on the house). My question is: what kind of glass should I use in the greenhouse? The main object must be to maintain insulation. Indoor lights will of course, be needed, but at the same time, it is important to allow the greatest visible light transmittance. Double pane/argon gas-filled glass is probably good enough to maintain heat in winter. But what about multi-coated Low-E glass? Any help would be appreciated.
     
  2. Nov 25, 2009 #2
    abaxter

    abaxter New Member

    Messages:
    499
    Likes Received:
    3
    Location:
    6B Southeast KY
    Miska, must you use glass? What about uv protected fiberglass? You can do a lot of
    insulating with fiberglass and greenhouse plastic in layers with dead air spaces in between. A really well insulated knee wall helps a great deal as well.
     
  3. Nov 25, 2009 #3
    Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,732
    Likes Received:
    3,530
    Location:
    Santa Rosa, CA
    You might look into multi-walled polycarbonate. It has great light transmission qualities and very good insulation.
     
  4. Nov 25, 2009 #4
    Miska

    Miska New Member

    Messages:
    3
    Likes Received:
    0
    Location:
    Norway
    Thanks. We have decided against polycarbonate in the walls because we do not want to inhibit our fjord view. Maybe polycarbonate in the roof would be an idea, though.
     
  5. Nov 25, 2009 #5
    Jon

    Jon Mmmm... bulbophyllum...

    Messages:
    4,437
    Likes Received:
    107
    Location:
    Denver CO, USA
    Are you planning on looking through the greenhouse to the fjords? I think condensation might be an issue if so.
     
  6. Nov 26, 2009 #6
    Ray

    Ray Orchid Iconoclast Supporting Member

    Messages:
    1,808
    Likes Received:
    580
    Location:
    Oak Island NC
    Depending upon the particular coating used, Low-E glass reduces the transmission of the wavelengths critical to plants pretty evenly, allowing about 70%-75% of the incident light to pass (compared to about 80% for an equivalent two-pane window with no coatings).

    As you're going to need supplemental light anyway, you should probably focus on overall energy savings to make your decision.

    I did a little digging and found the following for comparison of U-values (lower = better insulation):

    PPG Sungate 100 0.27
    PPG Sungate 500 0.33
    Polycarb 8mm twinwall 0.56
    Polycarb 16mm 3-wall 0.37
    Polycarb 25mm 5-wall 0.29
     
  7. Nov 28, 2009 #7
    Miska

    Miska New Member

    Messages:
    3
    Likes Received:
    0
    Location:
    Norway
    Thanks very much for the information, Ray, and your comment Jon. The PPG glass sounds good, and it even helps to reduce condensation. The problem is that it is not available in Norway, as far as I can see. I'll ask our window suppliers if they have anything with similar characteristics.