rocket heater not getting as hot as I expected

Any ideas

No insulation around feed tube and burn tunnel? No insulation around riser? Leaks between the firebricks? And is that another opening at the lower end of the feed tube? Please, read the book.

Peter Berg wrote:No insulation around feed tube and burn tunnel? No insulation around riser? Leaks between the firebricks? And is that another opening at the lower end of the feed tube? Please, read the book.

And i'm sure the gaps are respected!

Plus, you need barrel surface if you want quick radiant heat, which you haven't. And so on!

IMHO, do a tried and tested design before delving into weird gizmos!

pictures of the inside would help the knowledgeable folks on here decipher it. or even a drawing of it with dimensions.

Firstly I realize this is a highly bastardized rendition of a rocket heater but as always Im operating under some constraints and need it to be like this. If it would reach 6-700 on top Im pretty sure it will do what I want. And Ive seen similar heaters do this. I doubt the burn chamber or riser have any leaking I VERY carefully cemented. After the feed tube there are indeed some pieces that are not cemented yet as Im trying to incorporate an ash clean out tube that I havent exactly figured out yet. I also have no insulation I believed the fire bricks were insulation. Im also not completely understanding what the insulation is for. Is it to increase the temp of the burn chamber and riser or to protect the descending exhaust gas from being warmed. Any help is appreciated. Im a disabled ex-auto mechanic and the heating bills here are further disabling me.

Joe Sylwestrzak wrote:After the feed tube there are indeed some pieces that are not cemented yet as Im trying to incorporate an ash clean out tube that I havent exactly figured out yet.

Much easier to clean the thing by hand or with a vacuum cleaner. Leakage at that spot will hamper the stove seriously.

Joe Sylwestrzak wrote:I also have no insulation I believed the fire bricks were insulation. Im also not completely understanding what the insulation is for.

It's simple, really. The stove relies heavily on a high gas speed, this is achieved by insulating the riser. This will increase the temperature and therefore the speed. Around the tunnel and feed insulation will increase the combustion temperature which in turn helps to achieve nearly complete combustion. Hard fire brick won't insulate, in fact those will extract heat and hamper the burn.

The transition from the barrel to the horizontal pipe need to be spaciously. When you've all that and it won't help, add a better vertical chimney.

Make sure you have enough clearance from top of your riser tube to the top of the tank. If you don't have enough clearance I have seen this cause reduced performance.

Kudos on your design! I like the wheels!

Thank you guys so much. Im grateful that this forum even exists. I did reconfigure my exhaust some putting the first elbow up connected right to the 1 ft stub thats welded to the barrel and that seemed to help some. My top gap is exactly the recommended 2 in. It seems to rocket pretty well from feed tube into burn chamber but doesnt seem 700 at top of barrel. Ive seen in some rocket stoves where people insulated using wood ash. If I welded a divider in bottom to 1 in. over burn tunnel to isolate it from exhaust and filled it with ash and then slid a 6 in. stove pipe over my riser and filled it with ash do you think it would help ?

Hi, mind if I ask what is the general difference in where/how you will use the RS? I see that you make some interesting changes on it so I gotta wonder.

It sounds like you are starting to propose a lot of modifications and may start encountering secondary problems from the modifications (flow restrictions). Just make sure your cross sectional area doesn't decrease when you increase the area for more insulation.

To get the barrel as hot as possible the heat riser needs to be insulated. The heat riser should be long enough to give you good draw, yet the shorter it is the closer it will be to the hot combustion chamber.

If you really want hot temperature why not build a short lived very hot pocket rocket? The pocket rocket will get red/yellow hot.

Ok to start with I was forced to move from my affordable mobile home in a trailer park as I have built 2 LOUD chopper motorcycles and an even louder home stereo and like to play with them lol. I bought at pretty much the bottom of the foreclosure market and got a smokin deal on a 3 bdr. 3 bath home on 5 acres with 2 huge garages and a nearly new horse barn with stalls. House 2100 sq. ft. with only access to propane and I live alone with only meager disability income. Im extremely frugal and actually get along quite well except for heating. My mortgage holder is my brother who is an attorney + I had to borrow some cash for propane this year. This is unacceptable to me. Brother is cool and not hurtin but if this continues Ill have to sell my house. I have never b4 and will not be dependent on my brother. Pretty close to flat broke n cant bring myself to borrow more from brother. I love this house wild deer,turkeys,pheasants and Im a bit of a recluse. So I need cheap heat NOW. Have heated the part of home I live in with 23,000 btu kerosene heater and well placed fan so I thought my monstrosity would do the job easy. Which it is close to. Kerosene was only a little cheaper than propane and huge pain in butt. Found rocket heater 3 weeks ago and spent many hours researching and designing with what I had available and bought a cheap arc welder and trained myself to use it. Im almost possessed by the rocket Ive had to put 3 new notches in my belt since Ive discovered it. It could save my home. I just came in from the garage to see if you folks had answered my ash insulation question. Ive had to make improvements on my design. Wheels on heavy end a little splayed added brace and oiled all wheels and swivel points with rem oil. ROLLS much better. A gearhead so most of my stuff has wheels lol cept my boats. Im 1 man the wheels are only to get it in the house and will be removed. Noticed a few Polish sounding names-stay tuned Im the most pro Polish guy on the planet and I wont let you down. I have to get back to the garage. Ive nicknamed mine Rock-it and its calling me.

My last post didn't answer your ash question, but yes, fly ash or combustion ash can be used as insulation. It will improve your system but not by much. I don't think you will notice the increase in temperature unless you put about 4 inches of ash insulation around your heat riser. Yet, 4 inches of ash won't fit in your system.

You need cheap heat NOW, I again recommend building a pocket rocket. It will take a wrench like you 30 minutes to build max. You just need a 55 gallon barrel, a chimney section, a feed tube, some fire bricks under the barrel, then done!

Pocket rocket video:
https://www.youtube.com/watch?v=HcXlCc7lA74

This will give you heat now so you can optimize your Rock-It in warmth.

I dont need anything nearly as hot as the pocket rocket. To be frank that kind of heat frightens me. Mine is actually pretty close to doing what I need it to. Mainly I want to make 0 permanent mods to my home. Want chimney to exit through plywood placed in open window. Think Ill insulate the burn chamber with ash and raise the chimney some. any improvement will be good. Im nearing the end of the heating season for this year. Friend has offered 35 gallon drum so Ill build a little bigger 1 this summer. My Rock-it should heat enuf for the rest of this spring. Bottom line I believe the rocket heater will save my home. Thank you folks for being here !

https://permies.com/t/29470/labs/rocket-mass-heater-shippable-core

https://permies.com/t/30006/labs/pebble-style-rocket-mass-heater

How well insulated is your house?

If badly, pile strawbales on the outside for next winter.

House is fairly well insulated modular with 2x6 walls But Im just testing some changes I made and its looking pretty good. I got to looking down the riser and at all my cement joints the cement had oozed out into the riser. I carefully chipped out the cement. I also tapered the brick at the top of the burn tube leading into the riser and spread some cement on a 45 at the sharp corner where the floor of the burn tube meets the wall. Sort of ported and polished my J tube LOL. And I welded in a sheet metal retaining wall and insulated the burn chamber with ash. The little bugger is rocketing nicely now. No more fire creeping up the feed tube and is putting out quite a bit more heat. I think it will heat my home easily now.

always good to hear someone doesn't have to loose their home! thats awesome Joe! good luck

i seen a video of a similar stove as yours. he didnt use mass but extracted some more heat from flue with sheet metal fins. he just clipped fins out of sheet metal and hose clamped them on his flue. it did work to reduce the final exhaust temps, which means he extracted heat. watch where it goes out the wall for fire reasons. like cement board instead of the plywood. keep us updated man.

If one wants mo heat, metal bells are kind of weightless compared to massonry ones. And they can have bricks or pavers, or whatever piled on the sides, and top, to make a real mass. But which is dismantleable. Or you could go for the half barrel system!

http://s65.photobucket.com/user/mremine/library/NYC%20Rocket%20Stove%20Build/

That's removeable and pish easy!

Thank you Peter you told me what I needed to know. Increased flow and Bingo insane heat from little wood. Thank you Peter

Joe Sylwestrzak wrote:Thank you Peter you told me what I needed to know. Increased flow and Bingo insane heat from little wood. Thank you Peter

Well Joe, it's up to you.

But heat doesn't last when the rocket isn't fed, exept if you store it. You would use even less wood then!