On Apr 11, 7:01 pm, douglas sherriff <[email protected]> wrote: > The glimmerings of a masterpiece. Zig. > > Questions: > Do propane hotwater heaters have a central, vertical, "pipe" for > exhausting waste gases?
I believe they tend to be vertical, as this shows: http://www.diychatroom.com/attachments/f7/15426d1260731499t-propane-hot-water-heater-venting-drafthood.jpg > > Why? - Because if they do, we have a perfect tool to adapt to the highly > insulated, highly efficient, "rocket stove" prototype. . > > Do commonly used "oil type" heat transfer mediums (cooking, hydraulic, > used crankcase) exceed solder melt temperatures for solders used in car > radiators? > > Why? - Have to be able to make failproof pipe connections with barefoot > peasant tech. Also water medium is a PITA. Freesez, pressurises, explodes. It > doesn't usually contaminate the environment. Oil won't explode in the absence > of adequate oxygen. Water sure will. It doesn't matter too much, since its all about the pump here. You could fill the water tank with light oil and as long as you had a pump that could handle it, it should be fine. The hot water heater has a built in thermostat, so you can regulate temperature that way. If you use oil in a homebuilt heater, I would DEFINITELY have a thermostat of some kind to regulate the temperature of the stored liquid. I thought about adding additional heat (since hot water heaters are pretty anemic BTU wise) as well. As long as it was also linked into the hot water heater thermostat control, you could add burners to the inflow pipe, of course making sure the pipe could handle the heating. Perhaps you could solder on fins to help with heat transfer. Any way you do it, the idea is to preheat the returning cool fluid. If you are talking about using a rocket stove to heat the liquid, then I think a BIG thermometer with a RED LINE showing maximum allowed temperature should be attached. If you had to tend the fire for this sort of heater, I think you would want to have thermal mass inside the dwelling to help buffer the times when the heater was off and not tended. Im dubious about using oil.. it tends to be flammable so leaks would be a hazard, and if you wanted to avoid the freezing problem, some off the shelf antifreeze should take care of that. "Exploding" could be handled as in traditional hydronic systems.. with a hole in the top of the tank, or more fancy.. an expansion tank. A 6" PVC pipe, maybe 4 feet long and a small vent hole in it connected into the system as per standard hydronic system design (see above). > > Is there a cheap "velocity accelerator" (pump) that is not externaly > powered, that could be used to move "medium" from boiler to radiator? Don't know about not externally powered, but a "Tesla Pump" would do the trick, and can be assembled pretty cheaply from scrap. Google for many possibilities. > > Why? - Heat rising principle is ok if there's big diam pipes, vertical rise > (not semi horizontal) and more head = better circulation. BUT it is limited. > > It is entirely possible that the most "barefoot" approach ie. hot air might > be the most practical. A pure hot air system is more complex than this in some ways, in that you need a really good heat exchanger sealed up tight in a box. It will also use more power than a boiler system like this since you have to blow air across the flame to get the heat to all parts of the exchanger, AND you need to blow air through the exchanger to move heat into the dwelling. If you can get a hold of some scrap furnace parts, by all means. :) > > I am known to be easily transported into uncontrollable longlasting spasms of > ecstasy by elegant ideas and a smooth line. > > Does anyone know the intricacies of heat exchange mediums? I recall reading > that energy required to raise the temperature of water by x deg/unit mass is > very high compared to other materials. How bout oil and air? Its not only about temperature, its about Heat Capacity.. Its actually GOOD that something has a higher heat capacity in a tank system, since it will store more energy for you at a lower temperature. If you were using a tankless or intermittent small tank system, it might be more worthwhile to look into the lower heat capacity fluids because a fast rampup temperature would be important. Its hard to beat fresh water, at about 4.19 kj/kg*K . Normal oils have something like less than half that, across a spectrum. I welcome corrections and comments! > number one Kooona > > >>>>>>>>>>>>>> ZIG wrote: > > I'd think about using a hybrid hydronic/hot air system. > > http://en.wikipedia.org/wiki/Hydronics > > Setup a hot water heating system "in a box", well outside the yurt. > This could be as simple as an insulated cookpot with a low flame > underneath, but probably better would be a small propane water heater > since it has an integrated thermostat. To get more efficiency, put a > thick insulating blanket around it. The radiant heater (could be a > scrap automotive radiator) is in its own duct nearby, and the other > side of that duct is connected to your space. The pump could be an > automotive coolant pump. Using a water heater, you might want to make > sure the tank is vented to avoid expansion problems. > > You blow air through the duct, which is attached to the yurt somewhere > near the base with flexible, insulated ducting to heat the space. To > avoid noise, perhaps situate the fan inside the duct right in front of > the radiator, or just use the fan that came with it :) > > This avoids any trouble with CO or CO2 if the source air is ducted > from somewhere above and away from the heater > > --- On Sun, 4/10/11, Zig <[email protected]> wrote: > > > From: Zig <[email protected]> > > Subject: [hexayurt] Re: Stove question > > To: "hexayurt" <[email protected]> > > Date: Sunday, April 10, 2011, 7:30 PM > > > I'd think about using a hybrid hydronic/hot air system. > > >http://en.wikipedia.org/wiki/Hydronics > > > Setup a hot water heating system "in a box", well outside > > the yurt. > > This could be as simple as an insulated cookpot with a low > > flame > > underneath, but probably better would be a small propane > > water heater > > since it has an integrated thermostat. To get more > > efficiency, put a > > thick insulating blanket around it. The radiant heater > > (could be a > > scrap automotive radiator) is in its own duct nearby, and > > the other > > side of that duct is connected to your space. The pump > > could be an > > automotive coolant pump. Using a water heater, you > > might want to make > > sure the tank is vented to avoid expansion problems. > > > You blow air through the duct, which is attached to the > > yurt somewhere > > near the base with flexible, insulated ducting to heat the > > space. To > > avoid noise, perhaps situate the fan inside the duct right > > in front of > > the radiator, or just use the fan that came with it :) > > > This avoids any trouble with CO or CO2 if the source air is > > ducted > > from somewhere above and away from the heater. > > > -- > > You received this message because you are subscribed to the > > Google Groups "hexayurt" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]. > > For more options, visit this group > > athttp://groups.google.com/group/hexayurt?hl=en. -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hexayurt?hl=en.
