Ideas for heating a greenhouse

  • Ideas for heating a greenhouse

    Posted by Beachchic on October 11, 2022 at 5:07 pm

    Ok guys and girls, I was on a search for ways to heat a greenhouse and came across rocket mass heater. Im looking up youtube videos and other searches on this. Ideally I would build it like the Greenhouse in the snow gentleman and use the ground heat but this greenhouse is built already, its glass with a slab floor and a block foundation that we replaced last summer. I really would like to find a way if heating it because ohio winters get cold. I can grow lettuce, spinach and carrots till february they it gets too cold for a month or two and then I replant but I would love to grow more stuff throughout the year. Ive looked for solar heaters with no luck. So does anyone have any experience? What do you do?

    Annie replied 1 year, 5 months ago 20 Members · 44 Replies
  • 44 Replies
  • TagNBee

    Member
    October 11, 2022 at 5:15 pm

    I have looked into this a lot. I keep getting to the problem of input. without using geothermal, you stuck feeding the heat source. whether it’s a rocket stove or a woodburning stove it requires wood input. you can use electricity but again requires input. I am off grid, so this isn’t an option. I plan to use the geothermal option. If you find something else, keep us posted.

    • Beachchic

      Member
      October 11, 2022 at 5:39 pm

      Bahaha yes I know all about your Walapini 😀 Wanda and Danny made a few comments about this lol. I have looked too for a bit but wasnt much interested but now I want to do ALL that I can. Electric is not something I want to do nor is gas…those would both be wastes in my opinion. I for sure am researching all that I can on this because some time we will move to our forever land and I WILL have a greenhouse in the snow set up lol until then I will do what I can with what I have and be thankful that I have it, but look for ways to make it better!

    • Carl

      Member
      January 10, 2023 at 1:06 pm

      I considered the same thing Tag. I considered the input issue. Geothermal seems to be the best option. Of course down in S.E. Alabama we don’t get the winters like yall do with snow and then of course the ice storms that cover everything in a inch of ice every where you look, a little time in Oklahoma gave me that knowledge.

  • SunshineKid-GardenCoach

    Member
    October 11, 2022 at 11:09 pm

    I know electric for people off grid is not an option but I have used C9 Christmas lights in my small 8×16 hobby greenhouse for heat in the winter. When we had the Suri Snowmaggedon storm in 2021 in Texas, we got down to 9 degrees in southeast Texas with snow and ice for about 4 days. I had a 1/2 inch sheet of ice on the roof of my greenhouse and the doors froze shut but everything inside stayed warm and toasty. There is no electricity to the greenhouse but it is close enough to some outside outlets on the house that I was able to run an outdoor electric cord and plug in the lights. Used two 25 count light strings hung from the ceiling braces.

    • 2010

      Member
      October 12, 2022 at 8:56 am

      That is very interesting!! I didn’t know they put off that much heat! That is crazy!!

    • 5AcreWoods

      Member
      October 17, 2022 at 12:48 am

      Very helpful information. Have been using a farmhouse dietz lantern to keep small greenhouse above freezing. Two of them if temperature 32 or below. But putting in 16×20 low sidewalk and will try the lights.

      In zone 8 – thanks for the helpful information.

    • skainsgirl

      Member
      October 17, 2022 at 4:13 am

      I have used the same method for years to protect outdoor plants when I lived in zone 8b. Christmas lights and well secured plastic sheeting.

      • SunshineKid-GardenCoach

        Member
        October 18, 2022 at 10:28 am

        Yes, plastic sheeting and the C9 christmas lights work well event to close in a porch or pergola to help keep some tender potted plants protected in the winter.

      • 2010

        Member
        October 20, 2022 at 1:40 pm

        Do you use led c9 lights or the other?

      • SunshineKid-GardenCoach

        Member
        October 20, 2022 at 3:12 pm

        I use the 25L Clear Incandescent C9 Lights, the LED lights do not produce heat.

    • 2010

      Member
      October 20, 2022 at 1:39 pm

      Do you use led c9?

    • AmandaFishes

      Member
      October 30, 2022 at 4:19 pm

      Adding this to notes for when we have a greenhouse. We are in 5b and after the garden we built & grew this year, I’m not ready for it to be over for winter.

  • BiggKidd

    Member
    October 11, 2022 at 11:32 pm

    First off how large is your greenhouse? Second how much are you willing to spend? Heat storage is the key right up there with cutting down waste and loss.

    We’ve been using solar hot water for years now even in winter. If I had your problem and had a little money to spend here’s what I would do. I would use solar electric to heat water in large well insulated tank(s). I would then pipe the water in to the floor of my beds through PEX pipe. Thus heating from the root zone upward which will require the least heat with the most gain from that heat. I wouldn’t take the bed temps above 70-72 though. This would basically be a one time expense. Sure parts wear out and such but no ongoing labor or bill. I’ve bought 48 volt DC elements from Ebay with good luck they even have inline thermostats if you want to go that route. But I think you will need to worry more about the bed temp overall more than the water temp in the storage tank(s).

    • Beachchic

      Member
      October 12, 2022 at 12:41 am

      My greenhouse is 10 x 15, Ive looked into using water storage as my heat that would be ideal for a few reasons Ive even considered a fish tank as part of my holding tank but due to my layout the fishtank route would be my only way and even then it wouldnt be my best optionbecause it would take up a lot of growing space. The radiant heat would be a very good option but the problem is we just redid the block and hubby says that is a no go because we would have to jackhammer the floor and mess up the block. We have a friend that has radiant heat and it is amazing how well it works, it runs off their woodburner and it heats their house and humongus garage so well and doesnt use much wood at all. If only I would have had my wheels turning last summer.

      • BiggKidd

        Member
        October 12, 2022 at 12:47 am

        You don’t need the pipes in the floor they work as well or better inside the floor of the beds (in the growing medium). That way you aren’t trying to heat the whole floor just the root zone up. If the roots are warm and the air is above freezing you should be good to go.

      • Beachchic

        Member
        October 12, 2022 at 12:50 am

        Yes I realize this now I had a blonde moment, their was another comment after yours and I realized oh wait he means in the beds not the floor! Thank you! Im going to run this past the hubby and see where we can run with this idea!

        • This reply was modified 1 year, 8 months ago by  Beachchic.
      • 2010

        Member
        October 12, 2022 at 8:59 am

        Yhat is about the size of my greenhouse. What kind of heat you use now? This is my first year using a greenhouse and didn’t know what kind of heat to go with

      • Beachchic

        Member
        October 12, 2022 at 10:49 am

        I dont use any heat currently Ive just done stuff that is able to grow in an unheated greenhouse through the winter.

    • Squashmania

      Member
      January 4, 2023 at 7:05 pm

      I am interested in solar hot water. I would be interested in hearing about your system in the “utilities” forum.

  • AiNt-RiTe-Acres

    Member
    October 12, 2022 at 12:34 am

    One guy I saw had a walipini and he captured the rainwater from the roof. The rainwater was stored in 55 gal black drums. With his setup the sun and the greenhouse warmed the barrels by day and the barrels (which were now heat banks) warmed the greenhouse by night.

    BigKid’s on to something there though. You could do allot with a simple solar heater, especially if combined with a tank to act as a heat bank. With pex pipes you could heat the soil itself, any raised beds and the greenhouse. You could circulate the water with small 12v solar pumps. If you chose too you could do a closed loop system using a “green” antifreeze.

    • Beachchic

      Member
      October 12, 2022 at 12:48 am

      I just replied to him, one thing I guess didnt set in until I read your comment was the radiant heat idea. Instead of running the pex through the flooring you both are talking about running it through the beds themselves, now that is an idea I didnt consider. Ive been on the idea of water storage as my heat source but my concerns are really having the space for it and still having space for growing beds. Im going to run this idea past the hubby and see what he thinks about this. Im not real sure how steady of a heat it would be is another reason ive been back and forth. There are times we have a week or so with no sunshine. I really appreciate you jogging my brain, I will run this past the hubby and see what we can come up with.

      • BiggKidd

        Member
        October 12, 2022 at 1:26 am

        If you have access to regular power you can run dual elements AC from the power grid for extended cloudy times and DC & solar for the rest of the time. But really the idea here is to use a large enough storage tank to hold enough heat for that week of cloudy weather. A Decommissioned propane tank would be ideal and cheap. Insulate it with closed cell foam and paint that black. Insulate your pipes going in and between beds well. A buried and insulated tank would hold heat even better. Open or closed loop doesn’t much matter as long as your water temperature stays below boiling and above freezing. All of your pumps and such can be low draw DC pumps with long life. You don’t need to move a lot of water fast you want to move a little water SLOWLY so the heat exchanges.

      • BiggKidd

        Member
        October 12, 2022 at 1:34 am

        I just had an additional thought. If you decide to bury the tank put it down below the freeze zone all the way to the depth where the ground maintains a steady year round temp. If you’re already doing the work may as well do it right! Plus those 25-40 degrees of constant temp difference from the air temp will make a large difference in how the whole system works. It could also be used for passive cooling in the summer.

      • Beachchic

        Member
        October 12, 2022 at 10:51 am

        You have given me so many great ideas! I am going to show this whole conversation to the hubs because some if the comments I dont even understand how they would work. You have given me so much info I greatly appreciate it, thank you!

      • Annie

        Member
        January 16, 2023 at 3:30 pm

        Thanks for this entire conversation! So many ideas I’m taking notes on all of it!

    • Beachchic

      Member
      October 12, 2022 at 6:16 pm

      AiNt-RiTe-Acres was that Arkopia? Ivewatched him for a good while he has some good ideas.

  • TagNBee

    Member
    October 12, 2022 at 1:53 am

    What a fabulous conversation. I hadn’t considered the solar water heater through the beds. What a great contribution.

    • BiggKidd

      Member
      October 12, 2022 at 2:12 am

      I’ve been a problem solver and prepper all my life and a homesteader for the last fifteen years.

      • TagNBee

        Member
        October 12, 2022 at 2:15 am

        It shows

      • BiggKidd

        Member
        October 12, 2022 at 2:22 am

        Thank you! I probably should have said off grid homesteader for the last fifteen years. Before that I had been running inverter systems on my work trucks for ten or more years so we had power wherever we were. That came in real handy back in the 90’s when it was almost unheard of. IIRC I bought my first inverter in 92 or 93 for the truck that towed a diesel tractor that needed to be heated to start in winter. So we just plugged it in on the way to the jobs in the mornings. Once we realized how handy they were I put them on all my work trucks shortly thereafter.

    • Beachchic

      Member
      October 12, 2022 at 10:55 am

      Right?! It took me a minute to realize that is what was meant but then I was like ohhhh what a great idea. So much great info was given during this conversation I am really glad I asked this! Freesteading is working out pretty great, I was not wanting to sogn up at first I dont do the whole social media thing but I am fiinding I am really glad I have! Finding some really great people.

  • AiNt-RiTe-Acres

    Member
    October 12, 2022 at 3:16 am

    I’m finding allot of inspiration in this conversation myself. Wifey might get frustrated with me changing some of our plans mid reconstruction of our house lol. Already trying to work in earth tubes for cooling. Solar water heating for radiant heat sure beats splitting several cords of firewood every season. I like a good fire but I also like to make the best use of my time and physical labor where I can.

    • BiggKidd

      Member
      October 12, 2022 at 3:19 am

      Amen!

    • Beachchic

      Member
      October 12, 2022 at 10:57 am

      Absolutely! Set up the system to be so easy and maintanable that anyone can use it no matter the age and also agree with the wood that way the time can be used on other things that are needed!

  • DrumminSon

    Member
    October 12, 2022 at 3:38 am

    If you burn fuel to heat your greenhouse (propane electricity wood etc.) don’t just heat the inside air actually heat something like a barrel of water or a stack of bricks and it will retain the heat longer and cut down on your fuel consumption…

    • Beachchic

      Member
      October 12, 2022 at 10:58 am

      Thank you, BigKidd had mentioned heating the actual beds too using the heated water. There are some really great ideas here!

  • Rich

    Member
    October 12, 2022 at 11:34 am

    I am in northern VT. I have been researching out the same problem. Verge permaculture on YouTube has plans and is running tests on a geothermal design. I am considering using composting heat capture in combination with a rocket mass heater. The composting bin would be built into the side of greenhouse. The compartment it creates on the inside would be the base for a water tank/ fish tank. The rocket heater would be vented thru the thermal mass wall much like a kachelofen design. But I am open to any ideas and would appreciate any discussion of pros/cons before the build.

  • KimC

    Member
    October 12, 2022 at 11:59 pm

    I saw two YT videos on this subject a while back. One was a guy who piled all his leaves and any others he could get hold of all along the entire outside of his structure (except in front of the door), right up against it. Piled high. He said it insulated well enough through the winter to keep from freezing and created its own heat from composting, and they even got some snow at one point where he was located. Can’t remember the channel name, sorry, but you might be able to search and find it with key words.

    The second one was from a YT channel called Plant Abundance. He plugged in a simple, small water distilling unit in his and let it do double duty. The heat generated from the distilling unit was enough to keep his structure above freezing, and he got the water he wanted as a result too. He experimented and found that he only needed to increase the ambient inside temperature a small amount. I can’t remember how many degrees it was, but it didn’t require a huge difference for his plants to be okay.

  • Gypsy61

    Member
    October 13, 2022 at 1:01 am

    Do you have livestock? You can make a large circle with cattle panels and coil copper pipe in it (outside of the green house), and fill it with manure and compost materials to make a hot compost pile. Then run some Pex under the beds. Run into a holding tank and from the holding tank back to the pile.

    I saw someone used a hot pile method to heat shower water through a whole winter for people volunteering on their farm, years ago in a YouTube video. I think recirculating water would prob help keep lines from freezing for your application.

  • Nanagoat

    Member
    October 15, 2022 at 8:23 pm

    Im in zone 8. One of my coldest winters I put my grow out rabbit cages in the greenhouse for the winter. I had food all season. Then in the spring I planted tomatoes where the rabbits were and had a jackpot harvest.

  • AutumnRidge

    Member
    December 24, 2022 at 1:03 am

    Lots of things come into play when figuring heating loads in Greenhouses. Basically you must have enough BTUs to maintain your desired temperature in a given enviroment. Heat loss in Greenhouses can vary greatly such as use of single film or double inflated film, Infrared or conventional film, structure orientation, air distribution, type of floor, irrigation and drainage systems. Double inflated film will save you 45 to 50% on heat loss. another 15 to 20% savings if you choose Infrared film. Orientation is a catch 22. East / West allows more solar energy during daylight hours but cooling expense goes up. North / South equals less Solar energy collection but is easier to cool. Correct air distribution is critical to maintaining even heating. Bare ground is a very good heat sink. Its better to have gravel and a ground cloth to mitigate heat loss. Of course if crops are to be grown in the ground within the structure this is not an option. If irrigation systems uses water that is too cold and is allowed to wet surfaces other than what is intended, it takes a large percenage of the heat you have produced out through your drainage system. Just a rough rule of thumb, a 24 ft wide X 72 ft long X 10 ft tall greenhouse with double Infrared film inflated, takes approx. 175,000 BTUs to keep it at 70 degrees with outside air temperature of 32 degrees and no wind. Below 32 and wind another 175, 000 BTUs and it will be good down to negative 10 with 20 mph wind. One of our 24 X 72 X 10 Greenhouses is set up with two 175,00 BTU heaters. we only use the second one when temps drop below freezing to maintain 70 degrees. In our area we figure 25 BTUs per cu. ft. to mainatin70 degrees at negative 10 degrees. Hope this helps some to figure what you need.

  • The_Farm_on_Fall_Creek

    Member
    January 7, 2023 at 5:08 am

    7a here. 16×24 greenhouse and I have 4 heat lamps set to turn on at 38 degrees. This works well normally but for extreme cold which we had over Christmas( 2 degrees for low and 18 for high) I ran 2 single burner propane heaters at night and maintained 40+ degrees. Turn on before sunset and turn off next morning after sun starts warming it. I also keep two fans running year round, low speed in winter and high speed in summer. These work well with circulating the heat on cold nights. I have learned you just have to bite the bullet, I have found no way to combat cold without propane, wood or electric. I have not had issues but I have read where some had issues with smothering their plants using propane. If it’s not vented you will need some fresh are coming in. Multiple ways to achieve this depending on your setup with ventilation. Hope this info helps.

  • Siggy

    Member
    January 7, 2023 at 6:14 am

    We have a small solar hot water heater on the roof of ours. The pipe snakes through the floor . We also have 2 barrels of water in opposite corners with electric fish tank k warmers. Those are also run by solar. We hit minus 2 last year and it did not freeze.

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