concrete climate battery

Hi,
Would a concrete climate battery make sense in places with high water tables? Would concrete generally make sense? The idea is to avoid a rising water table infiltrating into the system and rendering it useless. Integrating it into the foundation as a single block could solve that issue in my mind...
What are your thoughts?

It's considered important to insulate the soil of a climate battery from the soil around it,  to keep the surrounding earth from becoming a heat sink.

Based on that,  I would say a battery poured as part of the concrete foundation might be OK,  as long as the foundation itself is insulated.

That being said,  I would want to store the heat close to the plants.
To me that would be either in the soil of the grow beds via an air to soil heat exchanger or in a water tank via an air to water heat exchanger.

Storing the heat in above ground beds or tanks means it will be surrounded by things you actually want to heat.
Most of the radiant or conductive heat "loss" will be desirable because your losing it to the plants and structures withen your heating envelope.
It also means you only need to insulate your mass horizontally ,between it and the flooring.

Can you give us more detail about Climate batteries please?

Climate batteries are a means to control climate in greenhouses or buildings.
Here a video at random:
https://www.youtube.com/watch?v=8qCucvh57Ro&t

Question;
That Youtube says that humidity is taken out of the hot air.
But if the pipes through the soil are steel or PVC, how is the water discharged to the soil?

In case of PVC or steel pipes you would install them sloping. Water would condense on the walls and you can suck out the water that collects. Usually climate batteries are built with corrugated perforated pipe so the water can be absorbed by the soil.

Thanks, I did wonder if that was the trick

Concrete is used as mass in lots of passive solar designs.

But there are benefits to vented tubes through the soil that are hard to quantify.  How does the air exchange below the root level change the soil biology and plant growth? How does the phase change of water condensing in the pipes AND vaporizing (which the concrete can't do) increase heat transfer?

I don't know the answer, they are just things to think about.

R Scott wrote:Concrete is used as mass in lots of passive solar designs.

But there are benefits to vented tubes through the soil that are hard to quantify.  How does the air exchange below the root level change the soil biology and plant growth? How does the phase change of water condensing in the pipes AND vaporizing (which the concrete can't do) increase heat transfer?

I don't know the answer, they are just things to think about.

Yes, there are benefits and they are not that difficult to quantify/calculate, if you know the composition of your thermal mass/substrate. Air exchange could be beneficial in building up top soil from below, creating a favorable environment for aerobic microbiome. But that would only make sense at 70cm and lowering the pipes progressively depth. You don't really need top soil at 3m below ground. In any case there is no vaporization happening. Water condenses in the perforated pipes and seeps into the soil through the perforations. If the air entering the concrete pipes is warm enough water might evaporate. In the case of "smooth" non-perforated surfaces, as I said, they would have to be laid with a slope to let water collect in a predefined easy to access spot, where you could just suck it off. Heat transfer is always higher when the thermal mass is wet.
The corrugated pipes need really powerful fans, but have a higher thermal conductivity, since a corrugated pipe will almost have twice the surface of a smooth pipe and turbulent flow is generally better than laminar when it comes to climate batteries. The smooth pipe usually doesn't have mold or Radon issues, which the corrugated pipes can have. The concrete pipes might have mold issues, if they're not coated. I'm not entirely sure about that. I have read that there are coatings for concrete water tanks, that can solve that problem. One could also just leave in the plastic pipes in the concrete battery.

I personally have decided against the concrete battery, since I might regret losing access to the subsoil.

There maybe an alternative.
In the past, we used concrete tanks full of large rock pieces.
The rocks were big enough to allow air to past through.
An air system drew hot air from the building into the tank to transfer heat to the rocks and return inside the building.
At cool times, the system was used to bring the heat from the rocks back into the building.

I've only read about smooth pipe used in earth tubes, where they have had issues mold.
Swabbing the insides with rags or pouring cleaners down the holes are some of the remedies.
Theses pipes are not described as being perforated.
In climate batteries, tubing that is corrugated and perforated reportedly avoids mold due to the actions of soil organisms.

I imagine a perforated tube without corrugations are better against mold than  ones with corragations.

William Bronson wrote:I've only read about smooth pipe used in earth tubes, where they have had issues mold.
Swabbing the insides with rags or pouring cleaners down the holes are some of the remedies.
Theses pipes are not described as being perforated.
In climate batteries, tubing that is corrugated and perforated reportedly avoids mold due to the actions of soil organisms.

I imagine a perforated tube without corrugations are better against mold than  ones with corragations.

Yes, earth tubes used for passive houses are usually smooth and non perforated. It is a different system. Some say a constant air flow, but  mounting a UV light at the intake should deal with most mold issues. A climate battery ideally sits directly below the greenhouse.
Most climate batteries are made with perforated corrugated tube.
The non perforated ones are better at avoiding radiation.

Other than the energy savings I would be interested in the efficiency of a smooth pipe climate battery. I could imagine it to be 30-50% less efficient compared to the corrugated tubes because of the laminar flow and the heavily decreased surface area.