Heat radiation is poorly emitted and absorbed by shiny surfaces but well emitted and absorbed by dark surfaces.Explain the following in terms of heat radiation.1.Shiny aluminium foil containers are used in take-away restaurants.2When runners pass through the finish at the London Marathon they are given a blanket made of shiny aluminium foil to wrap around them.3The cooling fins on the back of power amplifiers are painted dull black.4.Space suits are usually shiny white.5If you focus the heat from the sun onto a piece of paper, using a magnifying glass, it is easier to make a section covered in black print catch fire than a section of white paper.
1and 2Same reason: the alu foil reflects the radiated heat from the food and the runner back inside, to prevent colling off3Cooling fins work by radiating accumulated heat awaySo they radiate better when they are black4White reflects the most of the infalling radiation, so it prevent the astronauts to become too hot5That is so because, all other things being equal the black surface absorbs heat more efficiently than the white surface.
cover your returns with plastic seal them then turn on blower only for a minute if you feel air coming out of a vent then you have a return leak now when i say 1 minute thats what i mean you dont want to blow out blower motor
