Aluminum like all metals is a conductor and will reach the ambient temp and show heat just like if you did not use it.
FLIR does not see thru walls anyway - it only shows difference in temp of the surface scanned.
Unless your grow room is much hotter than the rest of the home or you are pumping lots of heat out of the house you will not be detected - even if they do scan your home.
sorry m8 you are wrong you are thinking of condution heat. i.e rockwool insulation will only slow the heat down before it comes through the other side. then their is radiation or AKA infrared heat this will also pass through rockwool, but it will not pass through mylar or tin foil it is reflected back in to the room if you have an air space between the mylar and the wall then conduction can not pass through nothing it needs to contact somthing for the heat to travle through radation or infrared heat is then reflected back in to the grow room, but still neds to be extracted out of the room or it will get to hot now you have the problem of where to extract all that heat?
there are 3 types of heat
Convection is the transfer of heat by the actual movement of the warmed matter. Heat leaves the coffee cup as the currents of steam and air rise. Convection is the transfer of heat energy in a gas or liquid by movement of currents. (It can also happen is some solids, like sand.) The heat moves with the fluid. Consider this: convection is responsible for making macaroni rise and fall in a pot of heated water. The warmer portions of the water are less dense and therefore, they rise. Meanwhile, the cooler portions of the water fall because they are denser.
Conduction is the transfer of energy through matter from particle to particle. It is the transfer and distribution of heat energy from atom to atom within a substance. For example, a spoon in a cup of hot soup becomes warmer because the heat from the soup is conducted along the spoon. Conduction is most effective in solids-but it can happen in fluids. Fun fact: Have you ever noticed that metals tend to feel cold? Believe it or not, they are not colder! They only feel colder because they conduct heat away from your hand. You perceive the heat that is leaving your hand as cold.
Radiation: Electromagnetic waves that directly transport ENERGY through space. Sunlight is a form of radiation that is radiated through space to our planet without the aid of fluids or solids. The energy travels through nothingness! Just think of it! The sun transfers heat through 93 million miles of space. Because there are no solids (like a huge spoon) touching the sun and our planet, conduction is not responsible for bringing heat to Earth. Since there are no fluids (like air and water) in space, convection is not responsible for transferring the heat. Thus, radiation brings heat to our planet.
HEAT TRAVELS IN THREE WAYS AS SHOWN AND DESCRIBED BELOW
1.CONVECTION
2.CONDUCTION
3.RADIATION1.CONVECTION: Occurs with the physical movement of air. There are two types of convectional heat movement. The first is natural, where hot air rises displacing the cold air and moving it down. The second type is forced or mechanical convection which occurs when an object, like a fan, physically moves or forces the air to move.
2.CONDUCTION: Occurs in a solid or liquid when heat from one object is transferred by touch, to another object. An example of this occurs when a pot on a stove will heat up by conductive heat transfer from the coil.
3.RADIATION: Radiant heat transfer involves the transfer of energy through an empty space or void. Any object that is above absolute zero, will emit radiant heat to colder objects around it.
The transfer of heat from the Sun is the best example of radiant heat flow. Although there is no matter in space, heat travels from the Sun to the Earth through radiation – or infrared waves. When these waves encounter an object, they can be either reflected or absorbed as heat. Highly reflective surfaces such as aluminum, are effective in stopping up to 97% of radiant heat transfer. With this in mind, it only makes sense to incorporate reflective insulation or radiant barriers, in any insulation system.
http://images.google.co.uk/imgres?imgurl=http://www.insulationdirect.com/images/examplehouseknockitoutofthepark.jpg&imgrefurl=http://www.insulationdirect.com/&usg=__X6zzS4Zed6rbKbD_1y3tyUHUWcs=&h=252&w=268&sz=17&hl=en&start=660&um=1&tbnid=jNfEfVAu1XXM8M:&tbnh=106&tbnw=113&prev=/images?q=reflect++heat&ndsp=21&hl=en&safe=off&client=firefox-a&channel=s&rls=org.mozilla:en-GB:official&sa=N&start=651&um=1
