Tiny House 6" Rocket Mass Heater

 

Source for clay, clay, and rocks on their support.

Notes: 

-The rocks hold heat well: at 5:30am the rocks are 12 to 15F degrees warmer than the rest of the interior.

Burning the paint off the barrel

Sand, clay and water.

the metal riser was a mistake....metal burn tunnels, feed tubes, and risers will burn out in one year or two of usage.  Only specially designed 4" systems can use metal without this issue. check this site out for changes in technology to RMHs DIY Rocket Mass Heaters DVD

Firebrick, high temperature mortar, and 6" pipe: J tube almost complete.

J tube ready for barrel.

Barrel on J tube and cob 75% done.

Things learned on this build:
 -the feed, throat, and j-tube's geometry should be symetrical for a perfect burn...my first build, see the older rocket stove build, was built perfectly symetrical and it's smoke smelled like steam instead of smoke (indicating a perfect burn). This current build is not a perfect square, but rather the feed and throat is rectangular resulting in output smoke smelling faintly like smoke which indicates failure to burn perfectly;
-cement backer board doesn't hold up to flame or coals very well;
-high temperature fiber cloth doesn't hold up to orange hot coals very well.

Temperature Data on the Rocket Stove:
Highest recorded temperature on top of the barrel is 432F

***Update 20190118

erm, so the rocket stove had to be modified so that I had an air gap between the rocket stove's base and the wooden floor (obvious yeah, but I thought ceramic tile and thermal blankets would do the trick -nope.) To do this I got a 1/4" steel plate (with legs), the entire J could set on; took off the barrel, lifted the J onto the plate with legs, rebuilt parts of the J a which came unmortared, rebuilt the clay base, put the barrel back on, and clay sealed the entire assembly.  ....Sounds easy??? try water, clay, and sand in 40 degree weather with out heat.

The steel plate modification cause an unforseen issue: I can only run the rocket stove for about three hours before the throat becomes hotter than the vertical part of the J tube. 

This limit on the rocket stove means my heat sink, the cob bench, takes a morning and an evening burn over more than two days to get the bench up to 80 or 100F.  Since I don't have four to six days off to get my cob  bench heat sink up to temperature, I cannot really test how long the cob bench lasts between firings.

I still can heat my entire building for eight hours with a small  bundle of sticks (due to the fact the rocket stove by design gasifies the wood and burns the gas too).

I am now looking at a batch mode rocket stove which would fit the life style of a wage slave such as my self at the moment.  Batch mode means no fire tending.

Clearly any one can build a rocket stove however, it is much trickier to build one that runs at maximum efficiency .....check out the video download here:

$15 if you want to build one that works!

***end 20190118 update***

Tiny House Wool In the Walls

 

Notes:
-The wool shrinks and compacts with wide temperature swings (120F to 38 F). For the wool to be effective as insulation, the wool must be held in place (chopsticks?, glue?)

Tiny House Through the Wall Solar Oven Install

***Update 20190118**
My reliable summer solar oven doesn't reach more than about 155F during the winter. I strongly suspect it is because the back isn't insulated. I was really surprised that my SAH worked so well but my solar oven lost so much heat during the winter it maxed out at 155F instead of 224 or 227F. 

I won't modify the solar oven until I have designed an insulated version and have the funds to construct it (e.g. remodel the current one). The remodeled version will have insulation, good seals for the door, and thermal glass which won't melt at 320F.

***end 20190118 update**

Yep, it looks ugly. Later it won't look so ugly and it will have nice shiny side fins which open and close by through the wall stiff wires.

Eventually the oven temperature maxed out around 224F.  This is without sealing the two side 2" pipes and without reflective material on the east and west sides (both of which I will do later).

A quick search shows the melting temperature of plexiglass is 320F, so I guess it is a good thing I didn't have the funds to add the two adjustable wings. The plexiglass will have to be replace with glass that can with stand 400 F.

Tiny House Cool Box

A cool box is....well, a box that is cool inside.  Mine is the thing sitting on the back of the tiny house's porch in the pic below (it hasn't been installed yet in the pic):

It is currently installed now. It has a 4" screw cap on the upper east side which is meant to allow cool air to be sucked up by the hot air vent (yes, my shell has to be air tight for this to happen). It also has a below the floor 6" inlet pipe on its lower west side. It's three foot tall and about 2'x2'.

On the day I showed my nephew the temperature differences inside the cool box compared to the inside shell temperatures:

•  92 degrees F in the hottest area (near the ceiling)

• 81 degrees F on the floor 

• 69 degrees F in the cool box

These temperatures were taken around 5:30pm. Yes it's hot and dark inside the shell still...there's no windows yet so I can check the effectiveness of all my thermal devices.

BTW: the shell itself has a temperature lag of 3 degrees F (with the door closed).  When the sun goes down, the temperature inside is three degrees warmer until 9pm.

Experimental Second Function of the Cool Box

This resulted in a failure from my view point. It warmed the cool box inside temperature by three degrees and wasn't effective in cooling the house.

The second function was meant to cool the tiny house with in reason, say 10 to 15 degrees F from outside temperatures (remember there are no windows and no air leaks at the moment).  This meant I would open the 4" top exit to allow cool air to be sucked out when the shell's door was closed due to the hot air exiting the hot air vent near the shell's roof.

Here's what happened:

Shell's Ceiling Temperature

Shell's Floor Temperature

Actual Inside Cool Box Temperature

This is a cooler day than usual this summer as the ceiling isn't 92F or higher (I've seen the ceiling get up to 117F).

 

This is failure because the cool box is now only 5F cooler than the floor of the shell instead of 12F cooler and the cool box is only 8 F cooler than the hottest part of the shell instead of 20F.

 

Therefore the cool box cannot act as a cool box and a room cooler.  Given the inlets and outlets, the second function doesn't really even cool the shell very well either. After seeing the data (and yes, I've collect more than I show here), I believe there should be at least at 16" cool in and a 12" cool out for a room cooler to work in a 10x12x12' shell.