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--00000000000045374805a6abcdf2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Re the blacking, when living in Montreal in an old house with hot water furnace and radiators , I wondered at a certain point if the radiators would radiate more heat if they were painted black. I couldn't find anything on the net, probably because I did not know what question to ask. It was just a hunch, because black absorbs more heat; but this heat would be coming from the inside, so to speak...? Still don't know but perhaps David's discovery holds the answer. I did not paint them black and did not use my chimes to test anything. Nancy On Wed, May 27, 2020 at 10:44 PM David Webster <dwebster@glinx.com> wrote: > Hi again Henk & All, > Original box found; says "Swedish Angel Chimes" on main panel: "Angel > Chimes A Product of Swedish Handicraft" on end tab. > YT, DW, Kentville > > -------- Forwarded Message -------- > Subject: Re: [NatureNS] Stove Blacking and heat transmission > Date: Wed, 27 May 2020 08:44:56 -0300 > From: David Webster <dwebster@glinx.com> <dwebster@glinx.com> > To: naturens@chebucto.ns.ca > > Hi Henk & All, It is one of these effects which must be seen to be > believed; the difference between 'black and white' (via dull grey). That > Swedish connection may be in error. Will be on the lookout for the origin= al > package likely about 50 years old. > > Dave W. > > On 5/26/2020 9:13 PM, Henk Kwindt wrote: > > Hi Dave and All, > > I don=E2=80=99t really have anything to add to your explanation but I tho= ught it > interesting that you have one of those =E2=80=9Cangel carousels=E2=80=9D! > We have had ours for at least 40+ years, they were quite popular in The > Netherlands in the 60s, didn=E2=80=99t know they came from Sweden. > Ours is packed with other Christmas decorations so it is being placed on > the stove every year in Dec. > We have not used the candles to =E2=80=9Cpower=E2=80=9D it for a long tim= e. > Since we have a more modern high efficiency stove the black top is not > directly accessible so I won=E2=80=99t be able to repeat your experiment. > Henk Kwindt, Cow Bay, NS. > > > > On May 26, 2020, at 7:47 PM, David Webster <dwebster@glinx.com> > <dwebster@glinx.com> wrote: > > Hi Steve & All, > > No my mill is powered entirely by upward flow of warm air; a thin circula= r > sheet of brass clipped to form eight vanes which slope downward to the > left. This fan consequently turns near side to the left. (Clockwise viewe= d > from above). > > The original unit, made in Sweden, was powered by candles and intended as > a Christmas table decoration. > > The fan is supported by a brass plate with three arms on each of which an > angel hangs and a brass rod hanging from each angel rings a chime as it > turns. > > I just stuck the working parts in a support made from a length of burned > out oven element, bent to be stable with the filling removed from the > vertical end by tapping. > > Just to confuse matters; note that what we call clockwise (down on the > right side) is counterclockwise from the clock's viewpoint. > > YT, Dave W. > > > On 5/26/2020 5:53 PM, Stephen Shaw wrote: > > Hi Dave, > I=E2=80=99m not familiar with your named device or its principle of opera= tion, but > we too have a small windmill that simply rests on top of our (also black) > wood stove and spins faster as the stove heats up. It works as a Peltier > device, with parallel hot and cold junctions built into a short aluminium > tower, the top of which is an air-cooled heat sink. I think it cost ~$130 > some years ago. The =E2=80=98hot' side of the Peltier junction faces down= to the > hot stove top upon which the frame rests, while the =E2=80=98cold' side i= s > uppermost, and its heat sink is cooled partly by the little rotating fan > and partly by radiation. With enough heating differential, the Peltier > effect generates a small current which is enough to turn a small DC motor > that carries the fan. > Is this like your device? If so, you may have simply have cleaned and in > effect flattened the stove top a bit so the base of the device makes bett= er > thermal contact with the Al base of the windmill, though the black-body > improvement should help a bit. A better solution in my case and maybe you= rs > would be to apply a thin layer of heat-sink compound to the base of the > tower. This is a messy paste based on zinc oxide, used standard in > electronics to attach a power transistor to an aluminium or copper heat > sink, while at the same time providing electrical insulation. It would > certainly enhance heat conduction to our windmill, but the compound is > white, sticky and difficult to remove once applied: I would become locall= y > unpopular if I so disfigured our black stove top, so I haven=E2=80=99t ye= t risked > the experiment. > Steve > > On May 25, 2020, at 7:55 PM, David Webster <dwebster@glinx.com> > <dwebster@glinx.com> wrote: > > Dear All, > > I heat the house mostly with wood burned in a fireplace insert and, > apart from some air circulation in under the fire box, up behind it and > out over the top, most heating is radiant off of the top. > > For decades I have used a Swedish Christmas heat mill, sold for > candles, which I adapted for stove top use, as a measure of heat release > rate. In recent decades it turned less frequently and for several years > not turned at all even with a brisk fire so I suspected wear and > increased friction at pivot points. > > The stove top had become dull grey in color so to improve > appearance I located a source of blacking last fall but it could be > applied only to a cold stove so was applied to the top, on first recent > warm morning this spring, and the increase in heat radiation from the > top was dramatic. With just a token fire that Swedish heat mill was > spinning full tilt ! > > This I assume was a practical demonstration of increased radiation > from a black surface (Black Body Radiation ?). And all along I had > imagined that stove blacking was just for appearance. > > Yt, DW, Kentville > > > --=20 Nancy Robinson 514-605-7186 --00000000000045374805a6abcdf2 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div dir=3D"ltr"><div><br></div><div>Re the blacking, when= living in Montreal in an old house with hot water furnace and radiators , = I wondered at a certain point if the radiators would radiate more heat if t= hey were painted black.=C2=A0 I couldn't