Ash problem

[Forsythe]

here's the link to the free "heating degree days" AKA "HDD" calculator website.

www.degreedays.net

[Forsythe]

Mar 16, 2022 12:46:43 GMT -8 milegas said:

Now, climate conditions here are very tricky. During autumn, winter and even spring it can be 15C today and -5 tomorrow and temps can jump around several times every two weeks. That is generally why people here aviod thermal mass since it is inert and takes time to heat up and cool down. Imagine fully charged mass after freezing day and spring weather tomorrow or worse freezing night and following day after not firing heater during 18C day.

This kind of temperature variations require longer burn periodes for cold weather and smaller mass to store heat overnight or less burning during the day and heat up in the evening to store heat for overnight. It is very tricky here.

well, with this style of heater, you should have a good compromise between instant heat and thermal mass.

A) The air channels underneath along the floor and up the back, coupled with B) how thin the heater is front-to-back, and C) the steel plate on top and along the front of the riser bell; should give you the ability to harvest more heat from the wood before it escapes up the chimney.

burning wood and putting the exhaust directly up the chimney wastes most of the heat you're generating with the fire.

Most masonry heaters are thick from side to side and front to back, so they take a while to radiate heat into the space, but I think this should work well for both heat harvest and relatively rapid heat transfer into the living space without holding too much heat when you don't need it. 

[milegas]

I agree, next is gathering magnesite bricks and casting core for spring to start building.

Thank you for a bunch of useful information and plans. And thank you for the time you have chosen to waste on solving my problem.

You are truly a great guy.

Cheers!

[Forsythe]

Hey, thanks!

Be sure to keep us updated on how the build is going when you start. Folks around here love to watch the progress and see the completed results.

Cheers

[Forsythe]

Hey milegas the more I think about this build, the more I think it might be easier to have the burn tunnel's feed-tube out in front and center, and make just one bell — the riser bell.

That would probably make it easier to design your ash clean-out ports into the system without getting in the way of the cross-channel flue that would have to run underneath the J-tube feeder and burn tunnel in my earlier design idea.

Plus, not having that cross-channel flue under the combustion chamber might make it draw better and avoid back-drafting after the burn cycle (in case your feed-tube cover / door isn't air-tight.) 

So, with the feed-tube out front, it might look something like one of these:

[Forsythe]

...or you could do the mini-bells on the sides, and the cross-channel flue wouldn't be in the way of the ash clean out port for the feed-tube.

All-in-all, it should be a little easier to accommodate the front-and-center J-tube feeder now with the depth measurement being a little over 22" instead of 19" like we had calculated for earlier.

[milegas]

I'm sorry i haven't seen you post, i have been distracted from heating thinking by everything going on. I own a lpg conversion garage and fuel prices kinda busted my business. But now wood price and retarded serbian government will provide us with natural gas cut off and electricity price rocket high made energy efficient wood heating really trendy subject.

Anyway, I've came up with a design that sshould compromise between mass storage and instant heat. Haven't made my mind yet between casted j core or fire brick in metal frame. Bell should be about half made of magnesite bricks, the bottom part around 2ft high, and the top should be metal with a double top and a fan blowing to side rooms through holes. I am aware that this kind of setup doesn't give much to heat storage but i am shure that it will fulfill the expectations i have. I have solved a big problem and that is as you may presume my wife that was charmed by my little fast heating 5 inch rocket that i have tricked way into the house from the garage. It is all metal with uncovered riser and external gas tank bell, another one of my creations... It managed to heat the house with more than half less wood than the conventional stove that we used. And the outside temps variated from 15 to - 5C in that period.

This design i plan to build should be, now you'll erase me from the forum, all day fire rocket. 7 inch properly built insulated refractory core should give enough heat and bigger chunks of fire wood could be used. Also i plan to build much higher feeder with air intake positioned at height of normal feeder and air tight top, something like gamera stove and secondary air intake. This kind of setup should give me at least 4 hour feeding interval.

[milegas]

freeimage.host/i/h0KLSs

This is my little badass rocket. It is ugly as hell but heats well. Btw I don't know how to post pic the way you do so your posts look pretty and neat.