ritchie brown

What about a grid of diffusers, like a lattice work, or even a horizontal or vertical simple  window sun blind, to partly shadow the Fresnel... and lower or slow heating speeds, or gradually raise temps?

"I'm currently adding a bedroom to the side of my house, and the whole south facing wall has been left open with the intention of capturing as much winter sun as possible and storing it in the concrete floor. "


I too am trying to do this, except on a larger scale.  
We own a huge Bauhaus-style building in central Bulgaria and want to use double-glazed passive solar collectors (glass covering black metal half-pipe in deep frames on the south-facing wall) to funnel heated air  between the floors.
Our apartment is on the top floor, and there is a cavity of about 3ft. between the apartment floor, and the ceiling below it..  (Floor and ceiling below it are shuttered concrete,) The frame of the building is concrete with brick leaves between. We estimate that we have about 10 or 12 square metres of glass. (from double glazed windows that we have removed, and bricked up the cavities, because the building was impossible to heat, with such a huge glass area.) If required, we could make up more panels and think that with say 10 sq metres of panels we might catch in the region of up to 8kw per hour total.   Bulgaria has 300 days of sunshine per year.

We hope that the passive solar system will work like a Roman hypercaust, and will funnel the heat after it has passed and heated the floor,  up through existing central chimneys, which I shall break into from the floor/ceiling cavity,  and lay insulated 'vent' pipes from. The end of the pipes will lay close to the inside of the cold north facing wall, so I hope to passively draw heat from south to north and then up the chimneys.  
The whole building is 8 metres high and 25 metres long, and 12 metres wide, so a massive amount of area and mass to heat. (82 feet x 40 feet x 25 feet high)

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My main problem is that in Bulgaria in summer, we often get temps exceeding 35C. ( sometimes 100 farenheit.) We already have a 280 litre solar hot water which works very well.  and gets our water way above boiling temps if not shut down. In emergency (power outage) our water system has got to 250 farenheit!  (I need to buy UPS battery storage for the pump)  

How can I shut the passive building solar system down in summer? Wooden close-able shutters?  Big canvas blinds, to cover the collectors?  Large metal 'shading-shelf' at the correct width and height above the collectors to shade high summer sun from the collectors?

Will we have to somehow shut the system down every night, so that the accumulated mass heat stored in the building doesn't escape to 'ground'  or alternatively suck in cold night time air, and then lose all the accumulated core & floor  heat,  up the chimneys?

How to do this? Any help much appreciated.

richard
bg

Thanks for the valuable pointers Al.

I did want to make a Kuznetsov-type free gas movement stove incorporating my existing fire box, ( because I paid a lot of money for it ) but alas, if RMH's and Russian stoves do indeed get up to those temps, then I understand the non-feasibility of such a project
And better that I know now, than to do a lot of work and spend more money, and end up with problems ..and probably also ruin the firebox.

A great pity, because I've had the stove for about six years, and it's unused, and in addition, the bloody thing cost me 1,000 Euros.. Damn!!
Still, if I can get an efficient Russian heater design and build it, then I shall be happy, and possibly save that amount in wood over a few winters.

I have a wood burner pyramid-style design at the moment, a design which is typically Bulgarian, but now, in the autumn and also in spring, if I fire it up, it goes from being fairly cold (which is the reason I light it ) to severely roasting and unbearably hot after 15 minutes. Hence the idea for a Russian stove which would release gentle heat throughout the day and night.

Can anyone recommend anywhere that I can get any 'Dragon heater'-type plans, which would incorporate a RMH front end (with a vertical fuel feed to a 'J' tube) with a couple of Kuznetsov-type masonry bells for heat storage?
I have a lot of space that I need to heat, so a marriage of the two designs would be ideal.

thanks for any help and suggestions

ritchie

bg (Bulgaria)

Hi.

I am interested in building a Kuznetsov 'free gas movement' stove, but think that two or more side-by-side bells are more efficient.
Doesn't the stacked bell design allow heat to convect, and thus to heat the top-most bell more? (the bell which should be the coolest) and only serves to warm up the exhaust more? If so, it is contrary in efficiency to two or more side-by-side bells, which give a closer to zero heat emission temp at exhaust, because the exhaust obviously gets cooler further away from the heat source.. (like bench mass storage design) I understand that stacked bells are better footprint-wise, and take up less horizontal space, of course.

I also have a new and very large firebox with pyrex side windows and pyrex front door, and fitted with a back water boiler. I had thought of incorporating this into the Kuznetsov design. Are there any disadvantages in using a steel stove with back boiler as a firebox? I have a reinforced concrete building, so mass and weight is not such a problem.

I intend having an insulated pipe exiting the firebox stove flue, with a drum above, as the rocket stove design.
The drum would sit 1.5" above the insulated flue pipe as does the rocket stove, and the drum would vent into a cavity which would lead to the first of the bells. Presumably an oil drum above would maximise burn temperatures, although I have not worked out how to extract fly-ash from the drum, as yet. (because it would be directly above the stove and behind two masonry walls. (outer cosmetic stone or brick leaf, and inner firebrick, with an expansion gap between the two))
Any suggestions or comments or ideas how to clean the drum and beneath it out? Vertical traps with access plates/doors below are probably not practical because of the width of the firebox/stove.

Scaled down side-by-side Kuznetsov 'free gas movement' bell systems could presumably work well with rocket technology, feeding into Chinese Kang-bed designs.

richie
bg