2007-01-28 04:52:04 · 9 answers · asked by thirteen 1 in Science & Mathematics ➔ Physics
The best insulator of heat is a medium which entails air cavaties because air is the poorest conductor of heat - whether receiving or reradiating it.
Thus, foam having air gaps or perforated surface is the best insulator out of the 3 given.
2007-01-28 05:40:30 · answer #1 · answered by anil bakshi 7 · 0⤊ 0⤋
I’m not sure in what application you’re thinking of using these three materials as insulators in so my answer is broad.
Aluminum foil would act as a conductor rather than an insulator in heat and electrical applications. Aluminum can be used as a heat transfer material to quickly conduct heat away from the parent material. (ie. heat sink) The Aluminum foil would be a choice if you were insulating airflow because it is a nonporous material. Aluminum foil material with an adhesive backing is usually used in this application. Aluminum foil could also be used in sound insulating applications. Typically, a combination of foam or cloth wrapped in aluminum is used for sound dampening.
The cloth would provide a barrier for heat depending on what material it is made out of and how thick it is. Woven fiberglass cloth has excellent heat resistance and is noncombustible. Check the thermal conductivity or R value (in/°F/hr) for an indication of cloths heat effectiveness as an insulator. Like many things, you pay for what you get.
Foam will act similar to the cloth in many insulating applications. Foam, like cloth has a wide range of R values. Foam’s advantages, depending on the kinds of foam, are ease of application and less health risks. This may or may not be things to consider.
After you have decided on one or a combination of the three, take some time to research the best product for your task. If you are making a decision for a home I would suggest looking at the site below.
Good luck!
2007-01-28 15:46:22 · answer #2 · answered by Michael J 1 · 0⤊ 0⤋
If you mean heat insulation then the best is:
Foam (I suspect you mean special inslatinoal foam)
then Cloth,
Aluminium foil is worst.
If you mean sound insulation it's pretty much the same.
2007-01-28 12:57:35 · answer #3 · answered by Leopold 2 · 0⤊ 0⤋
Foam -
not foil because it conducts the heat/cold to other side
not cloth because it's porous
2007-01-28 12:57:15 · answer #4 · answered by ecolink 7 · 0⤊ 0⤋
Tin foil seem to help the 9/11 conspiracy theorist so I say tin foil
2007-01-28 12:56:22 · answer #5 · answered by bob b 3 · 0⤊ 0⤋
i think foam, cos it has air pockets making it an even better insulator
2007-01-28 12:55:19 · answer #6 · answered by alexisvisjnic 1 · 0⤊ 0⤋
Foam.
2007-01-28 12:57:45 · answer #7 · answered by Anonymous · 0⤊ 0⤋
foil
2007-01-28 12:55:22 · answer #8 · answered by wofford1257 3 · 0⤊ 0⤋
I think cloth
2007-01-28 13:03:26 · answer #9 · answered by xyz123 1 · 0⤊ 0⤋