when you think about heat you're probably thinking about heating your home or a car
but managing heat is at the core of the design of almost everything around you and besides
being one of my favorite subjects as an engineer it's also a bit misunderstood I want to show you
something really cool about heat transfer and to demonstrate I got my son Remington to help me come
on over here Remy okay here's your question I have this piece of wood and I have this piece of copper
okay now I want you to touch them and tell me which one is colder okay so touch the wood first
okay just touch just like that okay now touch the copper here right there okay which is colder this
is colder yes why because of it's like metal is called and wood is hotter well he's close
well the truth is both of these things have been in this room for 24 hours they're the exact same
temperature and the reason why the copper feels colder is it's a much better conductor of heat so
your hand is 98 degrees Fahrenheit that copper is around 70. that 20 degree Delta is big enough that
the heat from your hand flows to the colder side of the copper whereas on the wood which is also at
70 degrees it's a much slower conductor of heat so today let's explore how heat transfer plays
a vital role in the design of almost everything around us and look at some breakthrough materials
like 3m's boron nitride cooling fillers and how it enables some pretty amazing Next Generation
products I'm Ricky and this is Two Bit da Vinci
huge thanks to 3M for working with us to make another awesome video highlighting some of their amazing climate Innovations
there are three forms of heat transfer one conduction the transfer of heat within an
object or two objects in contact two convection is the transfer of heat in a bulk movement of
molecules within fluid such as a gas or liquid third and lastly we have thermal radiation which
is an electromagnetic radiation generated by the thermal motion of particles and matter let's start
with our homes and see how we can maximize comfort and lower our energy bills if our goal is to keep
our home around 75 degrees or 24 degrees Celsius that's really easy when the temperature outside
is also 75 but as temperatures start falling in the winter the warmer air inside your home will
start to flow to the outside and the opposite is true in the summer if your home is made of wood
you'll likely find insulation between the studs this insulation has much lower heat transfer rates
than the wood helping to slow the transfer of heat for example in my house I have 2x4 construction
and the wood has an R value or resistance to heat loss of one per inch so two by four is an R4 but
the installation between the walls is typically around an r13 much better so therefore the better
the insulation you have the slower the heat will transfer this is why newer homes have much thicker
walls Matt Farrell my friend from undecided is building his house as we speak right now and his
walls are 15 inches thick a similar strategy is also used in thermoses like this one to keep your
drinks hot or cold but instead of insulation they work by creating a vacuum cavity within it and
without any air molecules there's no conduction or convection the metal is connected over this
rim for example so there is heat transfer from the inside to the outside but between the walls
here they're isolated with no air within a vacuum and as a result this can keep your drinks hot or
cold for hours but this vacuum also causes the air pressure inside to be much lower so it's going to
want to want to crumple in on itself and this is why most thermoses are made out of metals this is
a heat sink and this is used to keep your computer processor cool while it's running so in the case
of your thermos the heat comes from the hot liquid jet you supply in the case of a computer the heat
comes from billions of transistors switching back and forth at 3.5 gigahertz or whatever the speed
of your computer is so the base of your heat sink makes contact with the CPU and then these
heat pipe that you see running up in here take all that heat and transfer it up into these fins and
these fins have a huge amount of surface area and as air from a fan blows over it the heat from that
CPU is sucked up into the fans and then convection the cooling from the air blows over the fins and
cools off your computer a similar application is also used in cars like in a radiator in the case
of internal combustion cars front grilles house radiators where coolant is piped through the
engine components warming up and then pumped through a radiator where it is cool via a
convection by incoming air from the front of the car and when it comes to cars these grills seem
to be getting bigger and more distinctive every year in fact I would argue that this Grille which
is actually an engineering application a design consideration made not for the car but for the
function of that engine has become the most iconic part of modern car design so you're probably
starting to see that managing heat is a central tenant to engineering design and it's all around
us in a more high-tech application like electric cars or computers this thermal management becomes
really critical that's because now we don't just have to worry about heat but also electricity
which gets us to a very interesting relationship in most materials most really good thermal
conductors like this copper are also really good electrical conductors aluminum and copper for
example are both good at both in contrast thermal insulators like wall insulation or ceramic are not
only poor thermal conductor but they're also poor electrical conductors and this relationship can be
a bit of a problem when it comes to electronics if you think about circuits or the leads of a battery
it's crucial that they remain isolated if the positive and negative leads of the battery came
into contact you'd have a short circuit and major problems this is why electric wire is housed in
a protective non-conductive sheathing to keep wires separate but there's still a problem one
of the biggest enemies of electronics is heat it causes electronic components to fail prematurely
but most electrical insulators are poor thermal conductors which would trap it the heat in like
a blanket and this is where 3m's boron nitride cooling fillers are kind of a game changer they
are great electrical insulators but also great thermal conductors and this characteristic has
some pretty amazing possibilities for future Electronics EV batteries and so much more take
for example this computer motherboard it's full of transistors capacitors and other sensitive
electronic equipment that gets really hot but as you can see here they're all often exposed and
at a risk of debris falling in and causing short circuits but because these various components get
so hot you can't just cover them in a traditional electrical insulator and this would be a perfect
use case for 3m's boron nitride cooling fillers at its core 3M boron nitride cooling fillers are
in a family of advanced ceramic materials used to help improve thermal conductivity
and polymers while maintaining or improving electrical insulation boron nitride is often
referred to as white graphite because it has a hexagonal structure just like graphite does
but the difference is graphite is a thermal and electrical conductor whereas boron nitride is
electrical insulator and thermal conductor the 3M boron nitride cooling fillers are engineered
to line up easily and to form bridges that conduct heat in the direction of their orientation here's
ethereum's bra nitride cooling fillers compare in terms of thermal conductivity to to other
commonly used materials and here's a look at how they compare in terms of electrical conductivity
and this combination is kind of a game changer in previous videos we've discussed how companies
are building digital twins of the Earth where we can try to better understand and predict weather
conditions and other variables in our world but to do this we'll need sensors that can withstand
harsh weather without degrading bare circuits like this on our computed motherboard just
won't work we'll need materials that can provide electric isolation from the elements and water and
anything else that could cause short circuits but for reliability in the field these sensors will
also have to dissipate all that heat that they're going to produce to maximize operational life and
if this win-win wasn't enough 3m's boron nitride cooling fillers are also super low density which
means low weight and the potential for weight savings is really important in electric vehicles
and batteries thermally conductive materials are used throughout the vehicle things like
potting resins heat spreaders glues greases and thermal interface materials thermal Management
Solutions are needed in electric motors batteries sensors ECU electronics and even headlamps so more
cars can turn to LED lighting when it comes to batteries any weight required for outer casings or
thermal interface materials is weight that doesn't increase energy storage and therefore energy
density as companies race to find better and better cathode and anode chemistries they'll also
have to look at how they can better manage heat and save weight and that's exactly where these
cooling fillers come in weight savings result in higher energy densities which means more kilowatt
hours per energy storage given a certain amount of weight but an equally important component
of batteries is their thermal management overall early EVS that didn't have active Cooling in their
packs were prone to overheating and early energy degradation but as the technology matured we now
see cooling ribbons that run along outside the battery packs to transfer heat via conduction into
the ribbon and then convection out from the fluid to a radiator just like an old-fashioned internal
combustion engine but that's the out side of each cell in a battery pack but it's just as important
to have really good thermal conduction inside the battery cells to eliminate any hot spots and have
more even heat profiles 3M is one of those companies you've probably heard of but don't
see directly because their breakthrough Material Science and Innovation goes inside the products
we love but they're boron nitride cooling fillers have the potential to really be an engineer's best
friend in terms of heat management did you also know that 3M has a goal of going carbon neutral by
2050 and aims to cut its 2019 levels of greenhouse gas emissions 50 by 2030. the company is proud
that it has already reduced its greenhouse gas emission 72 percent since 2002. so it's great
to see so many Innovations and commitments to a more sustainable future from 3M you probably
don't spend a lot of time thinking about heat and thermal management but as an engineer that's
pretty much day one our jobs is to handle heat whether it's for Comfort like in your house or
your car whether it's the waste product of a thing like an internal combustion engine which is only
30 efficient and while EVS are way better closer to 90 95 percent efficient they still to make heat
anytime you have motion you have heat and as that builds up in something it'll slowly start to wear
out things prematurely so what do you guys think did I miss a few examples of ways that
heat transfers at the core of good design around the products that we love every day sound off in
the comments below alright thank you so much for watching if you like this video have a feeling
you'll like this video as well until next week I'm recruit Da Vinci thank you so much for watching