does wool keep you warm when wet? this question seems to get asked at least once a month in just about every outdoor and bushcraft forum. the answers, based on the experience of individual people, are all over the place.
the greenhouse structure plays a role in heat loss. wood makes a more energy efficient greenhouse because it is 1400 times more energy efficient than aluminum. in cold dry climates ice can actually form on the inside framework of an aluminum greenhouse. heating that type of structure is expensive.
wood stoves also have an ever-present risk of spilling hot embers or other material out an opened door, so building codes and certifications of the unit will cause the manufacturer to specify a minimum size requirement for the area the stove sits on that must be protected or made from non-combustible materials.
one factor overlooked about wood as an insulator is the fact that it performs like a thermal battery. since its mass is so large, it can store heat from the sun during the daytime and discharge this heat when it gets colder.
three factors determine how good a material is at absorbing and storing heat. the ideal material is: dense and heavy, so it can absorb and store significant amounts of heat lighter materials, such as wood, absorb less heat a reasonably good heat conductor heat has to be able to flow in and out
heat value varies based on the type of wood: a cord of wood with high heat value provides the heat equivalent to that produced by burning 200 to 250 gallons of heating oil. other heat values are listed above. cutting wood: freshly cut wood contains up to 50 percent moisture and must be seasoned dried to 20 to 25 percent moisture content
the average specific heat value of pine and spruce at 0 100 c is 2,300 j/kgoc. an increase in moisture improves the specific heat of the wood, because the specific heat of the water is greater than that of the wood. the heat capacity of pine is almost the same as that of bricks, although the density of wood compared to bricks is only 1/3.
the label shows the solar heat gain coefficient shgc and u-factor for the door. look for a low shgc in a climate that mainly requires cooling and a high shgc in a climate that requires heating. the range is from 0 to 1. shgc measures how well a product keeps out solar heat. look for a low u-factor; the range is from 0.00-2.00.
the handle is hot because of conduction of heat through the metal handle. conduction heats the pot that holds the boiling water. on the molecular level, the molecules near the heat source are heated and begin vibrating faster.
the boulton process usually is performed in the same cylinder used to treat the wood. in this process, the cylinder is charged with wood, and heated preservative is used to heat the wood charge for 1 to 24 hours. at that point, a vacuum is dn. finally, the preservative is returned to the work tank.
what is heat value? heat value refers to the amount of heat a wood produced when burned. heat value varies based on the type of wood: a cord of wood with high heat value provides the heat equivalent to that produced by burning 200 to 250 gallons of heating oil. other heat values are listed above.
the temperature decreased much more slowly because the heat was retained by the wool insulation. the above graph shows the expected results. wool insulates, so the heat producing object the container with hot water here, or the human body under real world conditions retains more of the heat, cooling down more slowly.
so far my design can be simply put as 2 metal cylinders one inside the other - now i want to fill the gap with a material that has a high heat retention. the idea being that when the fire is burning cooking food the heat will be absorbed by this material, then once the fire is out the material will start to radiate the heat.
for instance, arsenic, which is only 14.5% less dense than antimony, has nearly 59% more specific heat capacity on a mass basis. in other words; even though an ingot of arsenic is only about 17% larger than an antimony one of the same mass, it absorbs about 59% more heat energy for a given temperature rise.
re: pizza oven heat retention hi guys thanks for your input. i've used a door with a thermometer in it. the initial temperature with only the bed of coals and ashes goes up to 160 degrees celcius and then quiclkly drops to 140 degrees in about twenty minutes. over the next two hours it drops to about a 100 degrees which it holds for five hours.
there are several factors that affect the radiance of a wood-fired stove. the stove material. cast iron is the most common stove material, but there are also masonry stoves that are built with fire brick and other materials to hold heat longer. the size of the stove and the amount of mass that is exposed to the air.
the samples were prepared by glueing strips of wood to form 150 mm × 150 mm × 64 mm blocks. the strips were of various thickness, with a minimum of 38 mm. one 150 mm × 150 mm surface was exposed to the radiant flux. heat flux was perpendicular to the direction of the wood grain, which was horizontal in all tests.