Can the rocket kiln make an air conditioner? (Technically, an evaporative cooler?)

One common and energy efficient method of cooling is called evaporative cooling. This is sometimes called a swamp cooler. The common swap cooler goes in a window or on the roof and it consists of a water inlet thatfills a pan of water and a drum made of soething that wicks but doesn't rot or mildew, and then a fan that blows air through the wet drum cooling and humidifying the air. Here's a picture from a better explanation by The Spruce:



So basically, you have something porous/wicking, water and a fan.

This isn't a new technology,  Yakchāls were invented around 400 BC and can make ice in the desert. And ollas can cool water, not just water plants. India also uses these clay jug water coolers and calls them Matki. Perhaps we can make a sustainable swamp cooler with things we likely already have or can make?
(Clay can be refined from clay soils: https://practicalselfreliance.com/making-clay/).

So when the same principles are applied to cooling a room, it can look like a ceiling fan and suspended unglazed pots filled with water. Or possibly like this:

or like this:



The drawbacks to this type of system are that it adds humidity inside a structure and that it has to be refilled because it isn't plumbed unless a design is created that is sustainably refilled.

Do you think something like this could be created with the rocket Kiln, perhaps at the next PTJ?

Would you want to see something like this designed? Have you ever tried something like this? Do you have any design suggestions?

A rocket air conditioner would be awesome!

Evaporative cooling is good if you have both sufficient water and low enough humidity. (doesn’t work for all places though because a lot of places have plentiful water but high humidity, or low humidity but scarce water.).

A technology that can work without a lot of water consumption and can work in areas with high humidity is a desiccant based dehumidifier. A common desiccant that is used is calcium chloride salt. It is effective, non-toxic and low cost.

The way it works is when you have a very salty brine, say 30% (mass) salt, it will actually pull humidity out of the air.  This water entering the brine will dilute it to say a 20% solution.  A heat source such as solar or biomass energy can be used to evaporate off some of the water (and distill/condense it if desired), to return the brine to the original concentration.  That condensed water could then to used in a swamp cooler evaporator for example.

Another technology you mentioned, a radiative cooler, is a lot like a solar cooker but in reverse. 1) you need clear skies, 2) a basic optical design, 3) insulation, 4) thermal storage if you want an extended effect.

One difference is that with a solar oven, glass is often used for the window because it reflects some infrared and the greenhouse effect is an advantage for heating. However with a radiative cooler, you want the opposite of the greenhouse effect.  A different clear material might be suitable, or the window could be omitted.

A thermoelectric Peltier device might address some of the concerns with compressor-based refrigeration. 1) The devices are solid state so they should last longer. 2) they should be easier to run off-grid because: a) They don’t have a surge current when they turn on, b) they run on low voltage DC and, c) the current draw is low. d) they are relatively inexpensive.

The main disadvantage is that they are less efficient, requiring about 50% more electricity for a given amount of heat transferred.  I suppose the main advantages are that they are inexpensive and require minimal electronics. They could probably even be hardwired to a solar panel if desired, just to give an example of how simple an minimalist a system could be.  

Seasonal ice storage is of course another possibility.

Another design idea I wonder about would be to essentially use cold-pack technology, but make it reusable.  A salt such as ammonium chloride, when added to water, actually gets cold!  In theory the salt could be reused many many times if it was dried out, again using some heat source such as a solar oven or woodstove.  

Another technology is to use air as the working fluid in a compression refrigeration cycle.  This is preferably done with 2-phase flow, say air and liquid water.  One well-known design is the “Trompe”. Bill Mollison was a fan of. Traditionally they ran on hydropower, but I see no reason why they couldn’t be adapted to run on other sources such as solar electric or wind.

To clarify...  

You're asking if a rocket kiln can make unglazed materials for use in an air cooling device, right?
or
You're wondering if a rocket kiln can make the air cold somehow?

If it's the latter, I think it's a hard no.

Mike Haasl wrote:To clarify...  

You're asking if a rocket kiln can make unglazed materials for use in an air cooling device, right?
or
You're wondering if a rocket kiln can make the air cold somehow?

If it's the latter, I think it's a hard no.

Yes, I'm wondering if using a rocket kiln (or the rocket kiln, since I think there is currently only 1 in existence?) someone (me? a team of people? a skilled potter?) could make unglazed ceramics that would be a large component of an evaporative type cooling system, for use seasonally in mid-latitudes where it can be hot in the summer and cold in the winter (or full time in hot climates), especially when combined with other passive technologies.

I think it is also likely a "no" that the rocket kiln itself could be used as a cooling device, although I know that Paul has outlined how a rocket mass heater can be used to cool a house on his YouTube channel.


So, yes, the original question is the former:  Would it be possible to make a cooling device for essentially free, using unglazed ceramics (probably from home made clay) using a rocket kiln as the only firing mechanism? Does the existence of the Rocket Kiln open up a new area of appropriate technology?

If that were the case, one would have a technology that would work in many places, that might make a significant dent in the 10% of global greenhouse emissions that are currently used every year for cooling structures (air conditioning).

Mike Philips wrote:

A technology that can work without a lot of water consumption and can work in areas with high humidity is a desiccant based dehumidifier. A common desiccant that is used is calcium chloride salt. It is effective, non-toxic and low cost.

The way it works is when you have a very salty brine, say 30% (mass) salt, it will actually pull humidity out of the air.  This water entering the brine will dilute it to say a 20% solution.  A heat source such as solar or biomass energy can be used to evaporate off some of the water (and distill/condense it if desired), to return the brine to the original concentration.  That condensed water could then to used in a swamp cooler evaporator for example.

Are you saying to draw water out of the air through chemistry, and then use it to provide the water to the clay pieces? Are you suggesting this method so that it uses absolutely no power other than from the sun to evaporate and concentrate the water?  I was thinking a fountain pump that was solar powered, but it sounds like this might also work. I suspect that where I personally would deploy it (near Winemucca NV) I may not have enough moisture to pull from the air with that method.

Or wait, are you saying to remove the drawback of potentially damaging moisture in the house and recycle the water? That might work.

Mike Philips wrote:
Another technology you mentioned, a radiative cooler, is a lot like a solar cooker but in reverse. 1) you need clear skies, 2) a basic optical design, 3) insulation, 4) thermal storage if you want an extended effect.

I did? What did I call it? Can we just pretend I didn't and you can explain it to me like it was your idea and I have no idea what you're talking about?

Mike Philips wrote:
One difference is that with a solar oven, glass is often used for the window because it reflects some infrared and the greenhouse effect is an advantage for heating. However with a radiative cooler, you want the opposite of the greenhouse effect.  A different clear material might be suitable, or the window could be omitted.

On that note, I've been wondering if a variation on the rocket kiln would work as a glass kiln. I was thinking more of slumping than the initial Merging process that produces glass from sand or the crucible/gloryhole type glassblowing furnace, though.

(I mostly have no idea what you are talking about in between that quote and the next, sorry)

Mike Philips wrote:
Another technology is to use air as the working fluid in a compression refrigeration cycle.  This is preferably done with 2-phase flow, say air and liquid water.  One well-known design is the “Trompe”. Bill Mollison was a fan of. Traditionally they ran on hydropower, but I see no reason why they couldn’t be adapted to run on other sources such as solar electric or wind.

I saw Mollison explaining the trompe and it is wonderful technology but seems to require 2 things that I don't really have and that many places may not. 1. the ability to make a significant drop and 2. access/rights to a regularly flowing water source

My apologies for going off on a tangent. I was thinking about the general topic of cooling, and what I wrote may or may not relate to your situation, sorry about that.  I’ll try to clarify.

Cat Knight wrote:
Are you saying to draw water out of the air through chemistry, and then use it to provide the water to the clay pieces?

I mean if you have water to spare, and you don’t mind losing it to evaporation, I think it is totally fine to go with your original idea for using a swamp cooler.

Cat Knight wrote:
Are you suggesting this method so that it uses absolutely no power other than from the sun to evaporate and concentrate the water?  

As compared to conventional air conditioning (compressor based) , yes.  As compared to the swamp cooler design, no, because it is already solar powered.  

In theory it could be a way to save water, but this is coming from my somewhat idealistic, radical mad-scientist, bleeding-edge-inventor way of thinking. If you have a water source and you’re not concerned with losing some of it to evaporation, then it’s okay to disregard my comments about desiccants.

Cat Knight wrote:
I was thinking a fountain pump that was solar powered…

Sounds great!

Cat Knight wrote:
but it sounds like this might also work. I suspect that where I personally would deploy it (near Winemucca NV) I may not have enough moisture to pull from the air with that method.

In my opinion, I’m thinking it all depends on the water situation and how abundant or scarce it is, and to what lengths a person will go to in order to obtain water and/or conserve water.

Sorry about the confusion with the radiative cooler.  I was just generally referring to that ancient process of making ice in the desert, and the physics describing that.  I’d be happy to explain more about that soon.

You seem to be interested in ceramics. That’s awesome!  I didn’t mean to change the topic. Sorry about that.