BBR Masonry Heater 120 mm / 4.7" December 2018

[BenAlexanderT]

Hello there again and happy new year guys

After a lot of work,
I finally finished my first, not experimental, BBR heater (still some small details missing).
The bricks below the heat riser are clay hollow bricks, above the heat riser are traditional red clay bricks. and the top is made with four layers. The first layer, (bottom/up) 25mm/1" ceramic fiber blanket, the second layer is 25mm/1" Rockwool blanket, the third layer is galvanized sheet sealed with clay/sand mix and finally, for the fourth layer, I used a 20mm/0.78" piece of marble. For the plaster, I used one layer of clay-rich soil/sand mix 1:1 and 2 layers of lime/sand mix 1:1. I also used sunflower oil on the traditional red clay bricks to give them a darker finish.
The heater is now completely dry and as of the first of January 2019, I started using it. So far I don't see any problems but time will tell. I still can't give feedback concerning heat since it's the first time I'm using a masonry heater, so everything from now on is a surprise for me Photos below!!!

Link to Google Photos: photos.app.goo.gl/Ykx6sqWMHAHkYnb87

[Orange]

looks nice, you get 500C above riser and 50C exit temp? do you need that bypass?

[BenAlexanderT]

Sadly, I do need it, because with only 50C I get a lot of condensation and even with the tape some of it leak's through leaving an awful smell. Also, most of my wood is not seasoned so I get a lot of moisture out of them and I think there is only a win-win scenario having the bypass ready to use if it's needed Today I wrapped the exhaust pipe that's inside the house with 25mm/1" Rockwool blanket, so now the whole exhaust pipe, inside/outside the house, is insulated. I hope that I will no longer have condensation and smell. By the way, the firebox as an oven is awesome!! I made some potatoes and fish sticks

[Vortex]

Nice work Ben! Looks like you had fun over the holidays

What's your internal chimney made of, does the metal flue pipe just go down through to near floor level? How is your little bench connected into the flow or isn't it?

Thanks for sharing.

[BenAlexanderT]

Thanks, I did indeed. although most of my time I spend it thinking about the plaster and the top lid.

The heat riser is made of ceramic fiber blanket wrapped around a 120mm/4.7" pipe and I used a 180mm/7" pipe as a sleeve, afterward I removed the 120mm/4.7" pipe.
The exit starts 15cm from the bottom and it's a rectangular duct 20cm/7.9" by 15cm/5.9" with a length of 60cm/23.6" and it changes to a male pipe (120mm/4.7") at the end of it. Then it's around 3.5m/11.5feet stove pipe that goes straight up.
Link for a 3d model screenshot: photos.app.goo.gl/rNPvqBRrjAW93Xi59
The bench is connected as it can be seen in the photo above and it gets hot!! I need to buy some more concrete paver blocks for at least one layer



P/S: You can also see how the bench connects in the album linked up on the first post

[josephcrawley]

Burning dry wood will eliminate the condensation problems you're experiencing. Nice build!

[BenAlexanderT]

That's the plan for the next year. At the moment I don't have another choice, unfortunately. I might try some briquettes at some point. Thanks for the info though I hope it will cover my needs. Does the heater also increase the room temperature or just radiant heat?

[Orange]

yes, it's job is to heat the space. Has it dried, what temps do you get?

[BenAlexanderT]

The last days the room temperature is 10C. The humidity with the door open is around 45% and the last days that I had the door closed it increased to 55% humidity. Does that mean that it's not completely dry yet? The temperatures above are from a wall clock with a simple thermometer and humidity sensor.

I will take some measurements with the thermocouple sensor the next days and I will post them.

[peterberg]

I've had a look at the pictures and I think the hollow bricks aren't filled with clay mortar. I'd regard that as a mistake: there's not enough mass in them and the enclosed air is insulating. Whether or not you will be satisfied with this heater depends greatly on what you expect of it.

SInce the humidity is rising with the door closed not all the wate ris out yet, in some circumstances this could take weeks. Let it run as often as you can, at some point in time the temperature will rise and humidity go down. Using very, very dry fuel will speed up this process quite a lot.

[BenAlexanderT]

The hollow bricks are filled with concrete and only a few are with clay:sand mix 1:6. At some point, I'm going to buy an infrared thermometer and start measuring the heater's temps. The two sides of the heater that face the wall of the house are insulated with Rockwool, inside out. So, only the side with the firebox and the side with the bench are heating. My dry wood is limited so I mix them with some fresh wood. My expectation is to have close to 20C in the room. It is actually a small one, no more than 15 sq meters. I don't know if that can realistically be achieved but so far it's nice to have a cozy corner on the bench and an oven to cook

[BenAlexanderT]

If you are referring, Peter, to the hollow bricks that i didn't fill, no worries. These are only to the sides that I have insulated. I didn't want to spend time, energy and resources filling them since I was going to insulate their side. The hollow bricks that are on the firebox side and bench side, are all filled with concrete and some with clay/sand mix. They actually get hotter than the old red clay bricks.


P/S I measured the room and it's 13.3 sq meters/143 sq feet and it has huge closet. Also 1 sq meter/10 sq feet of that area is the heater.

Video link: photos.app.goo.gl/CTy2p4EhTZXvD2Ni6

[Orange]

seems like a perfect heater for the room and with insulation heat is directed to the centre of the room. Let us know how it behaves when dried out.

[BenAlexanderT]

Heater update and feedback.

After a season not using it, finally this season it was time to really test it.

The last time I lit the heater it was still drying, so I switched room in the house, but this season for several reasons I had to move back to the old room. After having some cold days it was time to light it up. I had my first REAL experience with a masonry heater that day. I did 3-4 consecutive burns that took approximately 3 hours and then I went to sleep. Early in the morning after 4-5 hours of sleep, I woke up sweating and I actually had to open the window to get some fresh air. The room door was also open and still, the heat was immense.
Now I finally get the masonry heater's slow release of the heat. With 3 hours of burn time, the room was warm for more than 10 hours and after 20 hours that I lit it again, the walls of the heater were still warm, around 30 degrees Celcius.

I am really satisfied. My only regret is making the side bench. I never actually used it and the room is to small for it

Thanks for all the information and help

[Orange]

great to hear that Ben!