Cast Batch Box Rocket Mass Heater using LTGS

Satamax Antone wrote:Fill with concrete. Sand insulates.

Another alternative would be to fill them with Cob.  I have plenty of sand and clay on hand.  

Steve Shelton wrote:

Satamax Antone wrote:Fill with concrete. Sand insulates.

Another alternative would be to fill them with Cob.  I have plenty of sand and clay on hand.  

Yes. Tho it's not as fluid as concrete.  Ans, since i've been there and donne that.  Vibrating witha vibrating sander work not too bad.  

Here's a pic of the same cement block that is covered in thin-set is now further covered in Geopolymer (GP).    The big test is which trowel notch size provides the best adhesion.  I will go with the smallest notch size with good adhesion.   This will provide the most efficient use of materials.  

The "redneck solution" Bell is now built.  It will be used temporarily to test the flow of air through the system.  Some time within the next week or so I'll fire it up.  

I hope to achieve a solid "Rocket" sound and temps exceeding 900 degrees F at the bell.  

Temperature just above the riser inside the bell.

Temporary Bell is leaking badly

Extending the chimney to 6' above bell top increased the temperatures.

I ran one last test to document the temperature progression through the initial stages of a burn.    This demonstrates the insulative properties of the Geopolymer Settings.

This was a small burn with half of the Batch Box filled with wood.  

Here's a pic of the 1st layer of the permanent Bell.  It is nearly complete.  I need to fill the remaining blocks with Cob to finish it.   The frame of the DSR is shown to show where it will fit.  However, it will be located on top of the 4th layer.  

The Bell is complete.  Next steps include installing the Bell Roof, Fire Wall behind, and hooking up the Chimney.  

Here's a quick update so far:

- DSR is performing above my expectations
- Our Electric furnace and heat pump have not run for the last 10 days.  Yeah, it's only November, but it could be the coldest November on record in Kansas City.  Also, yesterday a blizzard hit with 50mph winds and 6 inches of snow.  Some areas got dumped on.  It just missed us.  
- So far, we have been using 1 - 2 cubic feet of wood a day.  This is largely dependant upon if it's sunny.  If the sun shines, the solar gain from our south-facing windows allows us to only have 1 fire a day.  Each fire uses about 1 cu ft of wood.
- this would extrapolate to about 1 cord of wood for the year.  This is more than what I was expecting but is not bad considering I can collect wood for free.  
- It took several days to figure out the best way to set up the set-back thermostat to work together with the DSR.  We ended up setting the thermostat to 55o F.  This in effect only uses the furnace as a backup device.  
- Downstairs, where the DSR is located, is very comfortable at all times.  The lowest temperature recorded was 63o F. The average temperature overall was 67.5o F. The upstairs is a tad on the cool side.  During the daytime, the average is around the upper-60s.  The lowest temperature recorded was 58.5o F.   The average temperature overall was 65.1o F.
- 2450 sq ft home.  2/3rds of that is the upper level.
- I was worried that the DSR room temperature would be uncomfortably hot when it is burning.  This turned out to NOT be the case.  After the learning curve, the high temperatures were just a tad over 70o F.   Not bad IMHO.
- The electric savings should more than make up for the construction costs in less than 2 years.  WOOHOO!

Very nice.  How are you distributing the heat to the rest of the house?

Graham Chiu wrote:Very nice.  How are you distributing the heat to the rest of the house?

A thermostat controlled fan pushes air from the ceiling into the ductwork.

Final Build prior to a stone facade.

Exhaust chimney

Looking GREAT  Steve !

Can't wait to see pictures of your stone work when done!

Keep them pictures coming !

Could this chimney cowl be adversely affecting my chimney draw?

Hi Steve;  Hard to say from the photo. Does it have wire mesh in it ?    I have always used the simple cap (coolie cap) and never had a problem.
EDIT)   Steve with warmer temps and a brick bell sometimes its colder in the bell than outdoors. Draw can be harder to get going. Try heating the exhaust stack with a hand held torch … see if that helps.

Upgrade to DSR2