User Tag List

Informational! Informational!:  0
Likes Likes:  0
Page 1 of 2 12 LastLast
Results 1 to 8 of 15

Thread: help me heat my greenhouse for zero cost after initial investments

  1. #1
    D_muscipula's Avatar
    Join Date
    Aug 2007
    Location
    Oregon
    Posts
    1,500
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    help me heat my greenhouse for zero cost after initial investments

    Here's the deal. I have a small 6x8 or so greenhouse that I've had four 3 or 4 years. I've never grown any plants inside but I would like to start growing nepenthes in it, and not just khasiana

    I live in zone eight, and recently have been thinking about various methods of harnessing energy from the environment and using it as heat.

    So far here are ideas I've come up with to keep my greenhouse at a comfortable 55-60 during december nights.


    Caulk Caulk Caulk
    Add insulation to the north wall, cover in plywood and paint black
    Glaze all panels and add bubblewrap insulation
    Insulate the floor.
    Add gravel to the floor to act as a heatsink.
    Make a solar water heater and use the hot water to somehow heat the greenhouse
    Move my rain barrel inside, paint in black, fill with water and seal tightly.


    Any more ideas, the more the better. My goal is to have zero heating costs after initial investment.
    view my growlist
    http://grwlist.notlong.com

  2. #2
    Eats genetically engineered tomatoes Sig's Avatar
    Join Date
    Mar 2010
    Location
    Michigan -- If you donít like the weather, blink!
    Posts
    900
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I've head of people keeping a compost heap inside, which releases a lot of heat... but that's probably only good for larger greenhouses. All your ideas are really good though and in zone eight might be enough. You might want to keep a heater backup though in case something fails, so your plants don't die. If you don't mind a small cost after initial investment, you could use heating pads and heat the individual trays, which would be much cheaper than heating the whole greenhouse.

    You could also live in there... I'm sure the plants would appreciate the warmth and CO2.

    Good luck!
    Last edited by Sig; 08-22-2011 at 05:58 PM.
    Formerly known as Silenceisgod!

  3. #3
    Hear the Call of Nepenthes carnivoure12's Avatar
    Join Date
    Nov 2008
    Location
    Ontario, Canada
    Posts
    1,643
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Since it is a fairly small GH, you could probably use a small space heater to warm the GH. I'm sure it won't take too much energy to run one if you could insulate the GH.
    -Carnivoure12
    →Growlist

  4. #4
    D_muscipula's Avatar
    Join Date
    Aug 2007
    Location
    Oregon
    Posts
    1,500
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by carnivoure12 View Post
    Since it is a fairly small GH, you could probably use a small space heater to warm the GH. I'm sure it won't take too much energy to run one if you could insulate the GH.
    I have though about using a space heater, but decided against it.

    Let me say this first, I'm not a fatalist.
    That being said, let me say this...

    I want my greenhouse to be heated in a way that isn't dependent upon the activity of the sun, the electrical grid, and the condition of the nations economy.
    In the Victorian Era many greenhouses went cold across Europe and America.
    I'm not a fatalist, I'm simply thinking long term.

    For example.... It's a fact that solar flares have occurred in human history and knocked out power grids. While it's not a common occurrence, if my greenhouse relied on a space heater a solar flare could spell disaster for it's inhabitants. I wouldn't have room for all the plants on my already full windows.

    If my greenhouse is truly self sustaining (other than repairs, etc) I could move the easier HL plants off of my window and into the GH (in shade at first) and grow the more tender intermediates and HL species indoors
    Also, the more passive the heating system is the less chance for mechanical failure.
    A space heater may fail to work, but a barrel of water will always absorb heat and release it at night.

    ---------- Post added at 10:56 PM ---------- Previous post was at 10:50 PM ----------

    Here's a video of a solar water heater that heats water to 120F. It's on the roof of someones car port.

    I just installed a carport like the one in this video. The roof is basically flat, there is only a slight slope of an inch or so. The carport is also near the hose faucet and less than ten feet from my greenhouse.

    The question is, how would I use the hot water to heat the greenhouse? What about running the tubing from the carport into the greenhouse and snaking it through the floor?


    Here's the video
    I would skip to 3:43 the intro is a lot of fluff
    Last edited by D_muscipula; 08-23-2011 at 07:09 AM.
    view my growlist
    http://grwlist.notlong.com

  5. #5
    Steve Booth's Avatar
    Join Date
    Oct 2010
    Location
    Birmingham UK
    Posts
    150
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hi muscipula

    I would bury the pipes in the greenhouse soill, (can you insulate the greenhouse soil from the outside soil by use of polystyrene slabs or similar?) the idea being to heat a relatively large mass, so the heat gets released slowly over a period of time, similar to your water barell idea. This would have the added benifit of adding 'bottom heat' to any plants sunk into the soil.

    Probably plastic pipe would be the easiest as you wont need to make a load of joints, although its coeficient of heat transfer isnt as great as metal tubes so you will need to use more.

    Putting in a radiator or just letting the pipes conduct heat in air, will rapidly heat (when you dont really need it i.e. the sun is out so presumably warming the greenhouse) or cool the space, which is undesirable.

    Sounds like a usefull project, I'm also zone 8 so am interested in the results, good luck and let us know how you get on.

    Cheers
    Steve

  6. #6
    D_muscipula's Avatar
    Join Date
    Aug 2007
    Location
    Oregon
    Posts
    1,500
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Steve Booth View Post
    Hi muscipula

    (can you insulate the greenhouse soil from the outside soil by use of polystyrene slabs or similar?)

    Cheers
    Steve
    I am not sure Steve. The easiest way to insulate the ground would be to add a foam insert to the bottom of the greenhouse. But stryofoam would compress under the weight of me walking on it and definitely under the weight of a rain barrel filled w/water to act as thermal mass.

    This is something my mother mentioned earlier, if the ground is not insulated I'll lose heat to conduction.

    Okay new challenge? How do I insulate the soil if I need to?
    view my growlist
    http://grwlist.notlong.com

  7. #7
    Steve Booth's Avatar
    Join Date
    Oct 2010
    Location
    Birmingham UK
    Posts
    150
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hi muscipula

    I was thinking of the vertical aspects only, i.e. from the green house base vertically down say 700mm (28-30") to be lined with polystyrene, on the premise that heat rises, the downward disipation of heat would a) be small in value and b) if the heat is contained at the sides, the bit that goes downwards could be deemed as benificial as it then forms part of the heat sink.

    So the the polystyrene would not actually be walked on so wouldnt compress.

    Cheers
    Steve

  8. #8
    Whimgrinder's Avatar
    Join Date
    Jul 2011
    Posts
    3,875
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    While it's not a common occurrence, if my greenhouse relied on a space heater a solar flare could spell disaster for it's inhabitants.
    In a climate such as ours in the PNW it is possible to rely on "passive" techniques to capture what heat you need to maintain a greenhouse for highland species, under most circumstances. However, it is worth keeping in mind that once or twice every winter, we experience a few nights that dip down to as low as 8F, and there isn't a passive heat system on earth that will prevent serious freeze damage to the contents of any greenhouse that does not make use of artificial heating. You may be able to engineer a system that works when night temps do not drop below 40F, but beyond that, you will need to have a backup system at the ready.

Page 1 of 2 12 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •