Pop Cans? Just make the coop as a greenhouse .

Discussion in 'Coop & Run - Design, Construction, & Maintenance' started by Rangely, Nov 16, 2009.

  1. Rangely

    Rangely Out Of The Brooder

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    Fort Collins
    I don't want to rain on anyone's parade with the whole pop can heater thing, but this seems like a whole lot of work, in order to collect some passive solar energy and electrically pump it into your coop. I DO believe in the collection, it is the method I question. I simply made my coop as a greenhouse. Wish I had pics. My coop is 8'X3' with the top angled at 30 degrees(4.5' in back, 3.5' in front). For the top and front of the coop, I used corrugated Polycarb from Home Depot(12'X2' sheet cost $24).

    You're probably thinking: doesn't the warmed air escape through the corrugations at the top? The answer is yes and no. They make/sell foam forms that fit the corrugations top & bottom, but I wanted the option of sealing the corrugated "vents" depending on heat. So, in the dead of winter I just stuff them with straw. In spring/fall I remove the straw and let it vent excessive heat . In the summer, I simply move the coop under the 75 year old apple tree, where it sees zero direct sunlight. Venting is aided by having the section of the floor beneath the roost(6'X18") be 1" hardware cloth. Since cold air doesn't rise, this hasn't been a problem, although on really windy evenings it does pose a slight problem, solved by having a wooden flap that closes over top of it. The coop door is also lower than the "living" quarters of the coop, reducing heat loss in the winter.

    Insulation and critical mass are the keys. Of course, the back, walls & floor are painted black where it is practical, and the feeder is and old 5gal bucket(painted black). The waterer(old 2gal bucket) is painted white. Turns out chickens don't like hot drinking water. Who does? I used pressed wood on the outside AND inside. Having used 2X3 construction, this leaves a 1.5" gap on the sides and 2.5" in the rear. The sides I insulated with straw. The back, I have filled with heavy duty, seal-able garbage bags(OK. They are animal "body bags" from the vet) filled with water. Seems to work really well. I live in Colorado where we are not only a mile high, but also have 300 sunny days a year, so passive solar is easy and reliable. In the Winter, the coop runs about 40-50 degrees above outside temp during the day, and is usually around 25 degrees warmer at dawn. In the Spring/Fall, with the vents open, it runs around 20-25 degrees warmer during the day and 15 at dawn. With the vents working in the Spring/Fall, most heating results are from the water filled wall and not the greenhouse effect.

    Using straw and "pet" bags as insulation really kept costs down. The entire coop was built for less than $100. It doesn't require heat pads and/or water bowl heaters. In fact, no electricity at all. Since the top is clear, I use two solar landscaping lights to help the hens in the winter.

    Comments? Questions?
     
  2. patandchickens

    patandchickens Flock Mistress

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    Ontario, Canada
    Quote:The biggest selling point of popcan heaters is that they can super easily be retrofit to ANY coop. Whereas what you've got pretty much needs to be built from time zero, or would require extensive rebuilding.

    Also, in many climates i.e. the north, you really need to be able to shut off the popcan heater (or whatever) unless the sun is out. If I left my front solarized run (see below) open during cloudy spells I doubt I would get any net benefit from it, and if I was stuck with it that way all night too it would be a strong net heat LOSER from the coop. I suppose you could rig insulating panels that could close off your plastic coop front as long as you had other windows, but a little flap or popdoor or window is MUCH easier to operate than big insulating panels/curtains, and closer to 100% effective. A popcan heater is also easier to turn off in hot weather -- doesn't require major work like moving the coop or removing plastic panels or anything like that.

    I am not knocking your setup, clearly it works well for you and you have used many features that I think more people ought to use more often, esp. having good insulation on the outside of lots of thermal mass in the coop to buffer temperature swings.

    All I'm saying is, there are many people for whom it would not be such an optimum solution.

    Have you seen my solarized front run setup? There are pics on some other threads around here, I will try to find some to link here. It is sort of halfway between what you have and a popcan heater. It works *wonderfully*. It's a steep lean-to run on the S side of the building, 4x7' footprint, with both a popdoor and a window opening into it. I cover the wire mesh with shadecloth in the summer, which actually keeps out some of the heating that the building otherwise experiences, but in October or so I wrap the whole thing in not-quite-clear 6 mil vapor barrier plastic (would use corrugated panels if I had the cash) and run it as a passive solar heater. With the popdoor and window open on a sunny day, it pulls cool floor air in from the coop, warms it up real good, and sends it back into the coop via the window. Ideally I would have built it on a raised insulated wooden floor; as it is, it's on dirt and I sometimes have to run it for a day with the popdoor/window closed and the run's outside door partly open, to drive out humidity from the ground. Othewise it works great, and I get 5+ C (that's >10 F) boost from it in a 15x40 slab-floored building. Imagine what it'd do in a normal sized coop [​IMG]

    Have you done a page for your coop? It would be great if you would, with pics and the sort of discussion of solar-capture and thermal-mass issues you describe in your post. I really wish more people would see this being done successfully and build it inot their own coops instead of assuming all you can or should do is plug in a lamp for half the winter [​IMG]

    Good luck, have fun,

    Pat
     
  3. Rangely

    Rangely Out Of The Brooder

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    I read on some other threads that this is a bad idea due to condensation. I though I should address it. I can definitely see this as an issue in some parts of the country. Here on the front range of Colorado the climate is considered semi-arid. We only receive about 14" of total precip per year. This may seem completely impossible to some people but we don't need coasters here. Glasses of ice water don't sweat, even in the summer heat. We have whole house humidifiers, not de-humidifiers. No rice in the salt shaker either.

    Now, all that said, moisture does come from the birds exhaling in the vent-less coop. The solution is not overcrowding the coop. A 500 square foot coop with one hen will never develop a condensation problem. This set up has six hens in it, giving each hen about 9 cubic feet of coop real estate. That, coupled with the dry climate mitigates condensation almost entirely. I may see a thin fog layer on the polycarb on a cool spring morning, but never even close to the point where it beads/runs/drips, etc....
     
  4. Hoosiermomma

    Hoosiermomma Chillin' With My Peeps

    Jun 6, 2009
    S.E Ind
    Can you take pictures of your coop and post them? [​IMG]
     
  5. Rangely

    Rangely Out Of The Brooder

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    Nov 4, 2009
    Fort Collins
    Thanks Pat. Indeed I need to get out there with the camera.

    I think my dogs would appreciate the pop can heater for their dog house!

    The more I think about my set up, the more I think it is not well suited for many parts of the country. Anywhere with higher humidity will prolly experience unacceptable levels of condensation. So that leaves dry climates and most of those are in the southwest and too hot & sunny. I guess cold and sunny climates are are the only optimal ones for this setup.
     
  6. patandchickens

    patandchickens Flock Mistress

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    Ontario, Canada
    Quote:Actually that's not really a limiting problem. If you lived in a less dry climate all you would have to do is open some vents atop the walls (probably at the far end of the E wall, high up), same as if you *didn't* have the solar feature. Actually the solar feature will enable you to get along with less ventilation being open, partly b/c it keeps the coop temp up a bit (warmer air has lower relative humidity for the # grams of water vapor it holds) and also because the air being exhausted will be warmer thus carrying more moisture thus doing more good for a given volume of air exchange. Think of it as two separate functions. The solar thingie is a closed-loop thing that provides heat but no ventilation; then you also would have ventilation openings.

    What *would* be a bad idea would be to do what you're describing for the RUN. There, you have a large area (larger than the coop!) of chronically-damp ground that will always be wicking up more moisture from underlying and adjacent soil. A totally greenhousified run is essentially a perpetual humidifier [​IMG] Even with my leetle 4x7 jobbie, that for various reasons gets minimal rain coming into it even when not plastic-wrapped, I do have to open the door and dry it out periodically.

    I'm a bit surprised that you don't have problems with excessive heat loss through that large uninsulated 'window' type area on cold nights, though (even without condensation being a factor). I guess that is testament to what a LOT of thermal mass, allowed to collect a good amount of heat, can do for you! [​IMG] It almost sounds to me like your coop may be excessively warm for the chickens; a 40-50 degree difference when they go outdoors to the run sounds a bit iffy for them. But if it has worked for you so far, that's good.

    Pat
     
  7. DarkWolf

    DarkWolf Chillin' With My Peeps

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    Murray Kentucky
    For those of you who did NOT build your coop like a greenhouse and are still looking at the pop can method.. Lets not over work ourselves.. This is a simpler method of solar heating and takes far less work.


    http://www.instructables.com/id/Solar-Heater/

    Though the pop can method is indeed more efficient and has a better BTU output, the method above is fine and will raise the ambient temps within the coop more than enough.
     
    Last edited: Nov 16, 2009
  8. Hoosiermomma

    Hoosiermomma Chillin' With My Peeps

    Jun 6, 2009
    S.E Ind
    I thought I read somewhere where you mentioned using pressboard. Is that similar to osb ? If so did you seal it with anything? I can't wait to see pics as your coop sounds very interesting. We live in S.E Indiana and we have some pretty cold winters so I am trying to find ways to insulate without breaking the bank. lol [​IMG]
     
  9. patandchickens

    patandchickens Flock Mistress

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    Ontario, Canada
    I think a lot of people here are using "popcan type solar heater" to refer to the whole genre -- there are zillions of variations on the theme, from very simple (panel of glass or suntuf over a dark rear panel with a couple inches space in between) to very complicated (spending lots of time engineering things out of cans, piping, paint, etc etc etc). There are a LOT of designs to suit every taste [​IMG]

    And of course also passive solar thingies that double as chicken-use space (mine, and Klorinth's "sunporch"), and then the "greenhouse-walled coop w/ high thermal mass" that this thread was originally started for. And presumably other designs that someone else is using somewhere, too [​IMG]

    Plus less complicated things, like just putting a big dark drum of water where the sun coming thru the window hits it [​IMG]

    Pat
     
    Last edited: Nov 16, 2009
  10. sashurlow

    sashurlow Chillin' With My Peeps

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    Aug 18, 2009
    West Rutland, VT
    "Plus less complicated things, like just putting a big dark drum of water where the sun coming thru the window hits it wink."

    Any comments on putting dark beer bottles full of antifreeze in the windows? Would it make a difference?
     

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