How To Design A Climate Battery for a Greenhouse

How To Design A Climate Battery for a Greenhouse

In this video we will review how a climate battery, also known as a subterranean heating and cooling system works. There are a lot of misunderstandings on how to design and build one of these systems so first we will cover the basic theory behind them.

When designing one of these systems it is critical to understand how air moves through a duct system, why it is important to size it and how to go about doing this.

If you are looking to design one of these systems for your greenhouse you might find that this tool makes it a lot easier. You can purchase the tool at:

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What do you think?


Written by Aleksandar

Video MakerContent AuthorYears Of Membership


  1. I wonder why you need the pipes to move the air. Would a manifold at each end of a rock bed of sufficient depth achieve the necessary contact between the moving air and the thermal mass( rocks of the proper size). I am guessing solid rock is way more dense than soil so the total storage per cubic ft of rocks would be higher than a cubic ft of soil.

  2. so the pipes are empty and only the air from the greenhouse flows in them? no chemicals in them like in geothermal heat pump? do the tubes need to be made out of plastic or can they be made of metal?

  3. Great share, Will this be able to climatize a Mediterranean climate greenhouse? Where winter is cold (down to around zero Celsius) and hot summers up to 40 degrees Celsius.

    The greenhouse we are thinking to build has double glazing on the south and insulated walls on the north. Considering a Trombe wall at the back wall, as well shade cloths on the outside with ventilation vents at the lowest south side and autogas vents at the highest north side, plus 2 large doors at east and west.

    This kind of knowledge on passive climatizing is rare here so hoping to overcome the lack of local knowledge and examples by relying on info that I inquired in the last 10 years of Permaculture design and research and a great community of spread out international colleagues like you. Then provide this example to locals.

    I’m open to any advice in any direction. The goal is to be able to stay inside and grow plants all year round in soil an aquaponics systems. The greenhouse is not attached to a home, it’s stand-alone.
    Geo-location: 31.706334, 35.228147

    Thanks in advance.

  4. so, why would an air particle choose to pass through the center of the pipe system when there are twice as many corners to overcome? Only if the outtermost side pipes were 'full'? If I'm an air particle and I'm going to take one of the middle pipes, I have to turn 90 degrees into the manifold, 90 degrees after the manifold, 90 degrees into a small pipe, then 90 degrees into the outter manifold, and 90 degrees again to get into the exit pipe. The air particles who go through the outtermost pipes have two less corners to overcome. I imagine someone's thought about this already and it was still deemed appropriate to have the middle pipes? Has anyone built one of this with softer corners for easier airflow? I bet traditional masonry heater builders would have some wisdom about design possibilities for these kinds of fluid air dynamics….

  5. Thanks for a great series of videos.  Have you ever designed a climate battery using water in drums underground?  Clearly there are some logistical issues, but water stores much more heat than gravel or soil.

  6. You're an amazing person! Thanks for sharing this great knowledge. Curious, would it not benefit the "soil" to be small gravel and pebble instead? By replacing soil directly on the piping, wouldnt it hold underground temp better if it were stone? Any downside to this thought process?

  7. Good morning,

    Summary: Will your model address the concerns I have listed out ? If so, it seems a small cost to be able to KNOW prior to construction the the earth tube system was designed correctly for the above ground construction (and to be able to play "what if's" for that).

    Since you are in Canada, even though I see / hear the model input "for your US climate zone", you state your model is designed for cold climates. I am in US Zone 6b, Southern MO, it is rare for freeze line to extend 6" down. Is your model still accurate this far South ?

    We are at the design phase, looking at earth sheltered (North wall semi-underground and bermed up to top of 10' wall etc.) using 'earth bank' system for primary heating, would prefer to avoid the need for a secondary heat system to maintain temperatures above 33 F., with thermal pane glass (we have source of 1" commercial thermal pane glass at LOW cost, even if structural costs will increase due to additional weight).

    Summer cooling is of at least as much importance as is winter heating.

    Is this a good tool, that using references for r values etc. (are they referenced or linked, or will we need to look up each ?) for different glazing / insulation questions (what is the effect on minimum temperature if we increase the exterior closed cell insulation on the outside of a 8" poured concrete wall from 2" to 3") type questions ?

    I am aware of the 5 volumes per hour minimum winter but thought that 20 volume changes per hour would be more ideal for summer cooling – is there a rule or is this in the model to determine run time ? Is it better to run close to continuous or is it fine to have a 20% duty cycle ? If time the fan's are on is not a design criteria, then higher volume fan's with the ability to meet / exceed 20 volume changes per hour running full time make a winter heating / summer cooling simple – just differential thermostats controlling larger fan's.

    Placing a bi-level set of earth tubes placed 3' and 18" down (staggered vertically and input diagonally opposite outflow), but I can clearly see the advantages of more accurate calculations!!! (is 18 and 36" for THIS climate adequate, or do I need to be 24 and 48" (does your model consider depth placement ?), AND your info was the first time I encountered the idea of 3 levels of earth tubes. I had also been planning to use smooth walled tube for drops, raises, manifolds for less friction losses, and the corrugated standard = lower cost 4" sewage drainage tubes to connect the manifolds. Dose your model allow for adjusting (and give references for?) smooth (PVC) vs corrugated tubing ?

    BIG question: I had assumed 2 independent systems, 1 for each level to decrease manifold size/cost and to be able to utilize smaller / cheaper fans. NEW, if 3 levels, 3 independent systems and use one to zone on section with subdividing wall as more a warmer section??? (I see the lower cost in-line fan's at 400 and 720 CFM) Does your model account for design of 2 or 3 independent ground heat systems ?

    Thanks for your consideration,



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