grga
Junior Member
Posts: 76 
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Post by grga on Jan 7, 2019 3:26:01 GMT -8
This is the second season the heater is in use and it works very well. I fire it mostly 1x or 2x a day in extreme cold weather…   Link to the building thread is: donkey32.proboards.com/thread/2307/heater-cast-batchbox-bell-benchSome remarks: - The core is still in one peace. I build it from home made refractory = CACD cement + crushed stone bricks sand. It has a few tiny cracks which are there from the beginning. So I believe this is a good (and quite cheap) alternative for builders who do not want to invest in expensive factory premixed… - White oven is nice but it gets to max 200C which limits its use. It still is fine for food warming and some baking. - The heater overall works super. A bit annoying are only embers which stays unburned if the heater is closed while embers is still red (it need to be crack opened at least 1 or 2 hours more after fire dies). I need to clean ashes cca. after one week (7 fires) which is still fine but not as good as some of you? I guess this depends also on wood type. - I decorate it with led strip... - I still need to improve air vent to be able to fine adjust it in different positions. In next build I would change: - The use of high temperature silicone (1200 C) to glue parts of the core and heat riser was a mistake. The silicone becomes non elastic and does not allow different expansions between various parts. Better is to use only ceramic wool to seal parts… - I would not build bypass again as I never use it. Mostly because it complicates the build… It does help to run the heater faster but in my case I found out that at difficult startups (cloudy low pressure weather) it is more help full to open a window for a few minutes. The house is obviously quite airtight and the fresh air supply at the button of the heater probably is not enough for problematic starts (in most of the cases during winter is enough). |
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Post by drooster on Jan 7, 2019 11:14:48 GMT -8
In next build I would change: - The use of high temperature silicone (1200 C) to glue parts of the core and heat riser was a mistake. The silicone becomes non elastic and does not allow different expansions between various parts. Better is to use only ceramic wool to seal parts… - I would not build bypass again as I never use it. Very good information. Your heater looks so smart, did you use stick-on fake stone cladding? (I seem to remember from the build-thread discussion) and what material is that made of? |
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Post by Dan (Upstate NY, USA) on Jan 8, 2019 2:03:39 GMT -8
What happens when the differential expansion stops?
Does that cause cracking of the individual parts.
I always wondered if high temp silicone would work in this way.
I guess not...
How would you do it today?
Just dry fit the pieces and tie them together from the outside?
Thanks.
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grga
Junior Member
Posts: 76
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Post by grga on Jan 8, 2019 6:38:48 GMT -8
Thanks for your comments!
Tiles with imitation of stone are glued with the tile glue - the best I could find (very elastic and tested by the producer to 80C). The outside of the stove could get to max 60C at two fires per day...
3mm space between the tiles are filled with regular silicon, which is said to be fine to cca. 150C (stays elastic).
Yes I think a few cracks in the core happen also because of this hi-temp silicone. Next time I would only use a thin strip of ceramic wool (cut and split from the bigger piece in the width of cca. 5mm) between the parts of the core - like some of you are already doing (I thin Peter does it this way) and additionally secure the core with some wire or better metal strap from the outside. During the build the wool could be glued to one piece of the core by ordinary paper glue stick, just to stay in place...
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Post by Orange on Jan 9, 2019 11:57:35 GMT -8
How big/insulated is the space you're heating it and what's the room temperature? Does the led strip change colors?  |
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grga
Junior Member
Posts: 76
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Post by grga on Jan 10, 2019 3:15:40 GMT -8
How big/insulated is the space you're heating it and what's the room temperature? Does the led strip change colors? I heat the space in two floors (two floor house, open design, together floor surface 130m2, external wall and floor surface cca. 340 m2 and its volume also around 340m3) it has quite good insulation (my guess 0.3W/m2K in average). The heater can easily keep the house temperature between 22C and 23C if outside is around -3 to -5C at two fires a day and if there is no sun during the day (foggy weather). However I usually combine the RMH heater with existing floor heating to have higher comfort and make fire when I have time. |
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Post by Orange on Jan 10, 2019 11:56:56 GMT -8
grga, thats perfect!
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Post by Orange on Jan 19, 2019 4:54:00 GMT -8
if you only used RMH for heating, than the upper floor and rooms further away from RMH would be significantly colder or not?
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