How to heat small green house?

Discussion in 'Gardening & Plant Propagation' started by sisterpine, Oct 4, 2004.

  1. sisterpine

    sisterpine Goshen Farm Supporter

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    Greetings from southwest montana! I have a small 10 x 20 foot green house in which i grow a few flowers, salad greens tomatoes and the like. I really need to extend my very short growing season so am looking for the most economical way to heat the green house. The greenhouse has insulation in the walls but not the ceiling and is glazed with a single layer of polycarbonate on two sides and 1/3 of the roof. Some options are water barrels, propane, wood stove. What have you all used to heat yours?
     
  2. suelandress

    suelandress Windy Island Acres Supporter

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    My greenhouse has no flooring. This time of year, I surround the bed on all sides with grass clippings. They produce good heat as they break down. I have never done it in the winter (no clippings!!) My greenhouse is the same size as yours now. It was originally 10x48 and I used part of it as a chicken coop, with a bed surrounded by a hoop fence in the center. The chickens kept it warm enough until mid december. Curious as to what other answers you get....this will be the first year I try to keep some cole crop and lettuce alive all winter.
     

  3. insanity

    insanity Well-Known Member

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    Some what green horse manure,or wood mulch would put off some heat.Like said grass clippings. I picked up some mulch from the land fill this spring that was greener than i thought.Black in color but not broken down enough to use.When the guy with the front end loader ran into the pile it began to release steam.Lots of it.After he loaded it in my truck i walked back and stuck my hand in it.It had to be 100 at least.The temp outside hadn't been over 75 yet.Im thinking it was around that temp that day.I was wearing shorts at the time. Wood chips/sawdust have been known to get so hot as to catch fire when it piled deep enough.
    Horse manure also gets pretty warm.

    What low temps do you have there?Id think below 0 at times.If so you may still need back up gas/electric or something,at times. :D
     
  4. gobug

    gobug Well-Known Member Supporter

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    Use row covers inside your greenhouse in addition to the mulch Sue and insanity suggest.
     
  5. PonderosaQ

    PonderosaQ Well-Known Member Supporter

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    If the uninsulated parts are clear you can insulate them with bubble wrap. My last GH was insulated that way. In addition to the row covers suggested you can use a heat tape in a bed and then add the row cover. You'd be heating the growing area instead of unused space. I tried that for the first time last winter and it worked out well. Also be sure you are using the hardiest varieties of whatever plants you are growing. Whatever type of heat you try be sure to have a back up in case after all your hard work the first system fails. I have a back up electric heater. I've moved since last winter and my new greenhouse is just going up. I'm trying to figure out the heat thing too. Prices of propane and Kero have gone up way too high.

    Good luck,
    PQ
     
  6. farmmaid

    farmmaid Well-Known Member Supporter

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    Place hoop cover over the row and place a small cube heater inside. It will come on and off when needed, it is electric. Back-up would be a small wood stove...Joan
     
  7. uncle Will in In.

    uncle Will in In. Well-Known Member Supporter

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    If you heat the whole house in bone cold weather, wood is the only thing that might cost you less that you are willing to spend on the plants you are growing.
     
  8. sisterpine

    sisterpine Goshen Farm Supporter

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    Well thanks for all the information! I have been thinking about this topic and discovered the following: Our winters always include several days of -20 -30 degrees during Feb. So if I plan on only heating till the end of January that would extend my growing period by 90 days! I could also start heating the greenhouse in say beginning of April and get my plants in earlier! In fact I could just forget about Feb totally LOL would love to do that! I think I will talk DH into helping me put a wood stove in the corner with some of that non burnable cement type board behind it. I will also put plastic (of whatever type i can afford) over the polycarbonate glazing and make some row hoops for starting plants earlier in the spring. Your ideas helped alot- many thanks! Kathleen
     
  9. jackie c

    jackie c Well-Known Member

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    In addition to the replys already recieved, you can heat very cheaply at the ends of seasons with water. Get some plastic or metal drums, size does not matter, paint black, fill with water and place them on the north side of the green house. At night they give off heat. You can use plastic milk containers or anything that will hold water, anything you can paint black. Hope this helps a little.
     
  10. Timber

    Timber Well-Known Member

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    I'm in the building of a greenhouse, hope to get it up before the snow. A cattle panels and plastic design.
    I heard of a Canadian family a small local grower I believe in Ontario that sprayed bubbles on their greenhouse. It was a big success.
    A friend emailed the info I'll send off an email for more info.

    Timber
     
  11. Cyngbaeld

    Cyngbaeld In Remembrance Supporter

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    Without supplimental lighting, you will not get enough plant growth for healthy plants thru the winter. Frankly, I would not plan on anything but salad greens from mid october on. Extending the season from march or april and having warmer conditions for heat loving crops like tomatoes and peppers , squash and melons thru the summer will be the most cost effective.
     
  12. sisterpine

    sisterpine Goshen Farm Supporter

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    Timber: Sprayed bubbles? that is interesting. Yes i am thinking about salad greens through the winter and then earlier starts in the spring and a bit later in the fall. It is now the middle of October and my tomatoes are just ripening along with the squash! I started these plants may first but we have had a very cold wet summer and plants took forever to mature. I would love to hear about the bubbles! Kathleen
     
  13. sisterpine

    sisterpine Goshen Farm Supporter

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    Yes I am thinking about the water barrels just dont know where i would put them in this little green house. I have a plant bed on the north side where i grow my beans etc. so will have to work on this a bit. I did take out the watering water barrel last week to see if i had room for a small wood stove or sorts, will have to wait till DH gets back from his trip to know for sure. I will ask about barrels too. I know the biggest problem is the uninsulated roof and the single layer of polycarbonate greenhouse panels....so much to work out! Kathleen
     
  14. Timber

    Timber Well-Known Member

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    SP here's the link that was sent
    http://www.tdc.ca/bubblegreenhouse.htm
    I did a search here saw that it was mention earlier by john#4

    Some time ago Mother Earth News made a pulse heater out of downspout tubing in their first greenhouse. I'm not sure but I think it caught fire because of..

    How about making an outside solar collector with black plastic tubes filled with antifreeze, then plumb it inside into the barrels or some kind of storage containers under the soil beds to radiate the heat.

    A thought of adding one of those outdoor wood boilers to heat the home and another zone to the greenhouse would be real nice.

    Timber
     
  15. greg273

    greg273 Well-Known Member

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    Compost can release a lot of heat, as well as carbon dioxide, that your plants will love. ( a good, active compost pile can get up to 160deg) I've used the heat from that to warm oil for making biodiesel in the winter... very nice to have 'free' energy in the middle of the cold season.
    I would also recommend some sort of insulative air space, perhaps a layer of plastic sheeting attached to the undersides of the framing, any dead air space will help keep your heat in.
    If you decide on a woodburner, i can attest that the 'barrel kits' are a good buy, in fact, i'm heating my cabin for the second year with one and it perfoms well. (the price certainly is right for those on a limited budget).
    Also, using dark-colored water barrels can be an effective way to store heat, if the sun can shine on them for sufficient time in the day.
    You also might be able to get a waste-oil burning furnace, then you can use your own used motor oil, or waste vegetable oil, or glycerine, or some other cheap fuel to get by.
    \

    good luck!
     
  16. sisterpine

    sisterpine Goshen Farm Supporter

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    greg: thanks for reminding me about the clear plastic and creating an air space. that is something i thought about last year and then forgot. i will beat feet to town tomorrow and get a bunch and hang it up!
     
  17. treeguy

    treeguy Active Member

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    I know one guy who salvaged a furnace out of a mobile home and set it on blocks and added a fuel tank outside.another option might be a furnace from a camping trailer. I know in florida they just light a kerosene ball like the kinds they used to use for road work to keep the frost off the citrus trees
     
  18. sisterpine

    sisterpine Goshen Farm Supporter

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    Hi Again! I found some greenhouse plastic, 6 mil and uv protected and guaranteed for 4 years on a site and ordered it , should be here soon. I am also thinking about installing along the back wall tall pieces of black pipe, like maybe drain pipe with cap glued to bottom and fill with water and cap the top? Thought I could buy them a bit at a time through the winter , would be looking for something that could be capped and would be like 6 inch diameter. Should hold some heat. DH says i can put a small pot belly stove in if i save up the money on my own (not too hard to do). and also the motor home heater is a good idea since we already have propane! You guys are great, it is true many minds are better than one! Kathleen
     
  19. cowboy joe

    cowboy joe Hired Hand

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    Greenhouses are typically warm during the day time hours due to the effects of the sun. Keeping the space warm enough is the big challenge during the night time hours in the dead of winter. Assuming that there is sufficient thermal mass inside the structure (i.e water barrels, rock, etc) some of the heat gained during the day from the sun can be retained by installing blankets of insulation over the glazing during night time hours. The biggest drawback to this system is the commitment to installing / removing the insulation on a daily basis.

    A more efficient greenhouse design entails a 'half' greenhouse, or lean to, attached to the southern side of a house. The installation of upper & lower vents allow the greenhouse to exchange cool, humidity air with the dry, warmer air of the house. The advantage is two fold: the greenhouse remains warm & some humidity & oxygen makes its way back into the house.
     
  20. bethlaf

    bethlaf Homegrown Family

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    put a good compost pile in there, it will heat it up good, think BIG terrarium , them oisture will help the plants too ! put your compost pile around a large water barell , and its even a better idea:D