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Building Material Absorbs and Releases Heat
Zothecula writes "Researchers at the Ningpo, China campus of the University of Nottingham (UNNC) have created a new heat-regulating material that could be used to cut the heating and cooling costs of buildings. The non-deformed storage phase change material (PCM) can be fixed so that it starts absorbing any excess heat above a pre-determined temperature and releasing stored heat when the ambient temperature drops below the set point. The researchers say the material can be manufactured in a variety of shapes and sizes, even small enough so that it can be sprayed as a microscopic film to surfaces in existing buildings."
I'm pretty sure that almost every substance on earth "absorbs and releases heat".
Whoa! Just like... matter!
Can I patent this thermodynamics stuff?
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Never been known to fail..."
Link no worky. False link.... Its a TRAP!
..."adobe". [Dr. Evil pinkie]
Its all about bringing the state change into a temperature zone that can utilized, and it has to be cheap.
Damp Magnesium Sulfate always worked for us.
How does it react to common hazards ... such as fire? Boom? If it goes up like a pine tree then it isn't very good, imo.
After all the articles about plagiarized and outright made up research in Chinese universities, I have to take every "discovery" they announce with huge skepticism.
Note that this kind of material only works to increase the heat capacity of the building, so it will only work when the temperature fluctuates across the phase change temperature over the course of the day. You'll still need a heater if it gets cold and stays cold and an air conditioner if it gets hot and stays hot. The big benefit is that the heat capacity only applies across a narrow temperature range, so it's relatively easy to maintain that temperature passively.
There's no point in questioning authority if you aren't going to listen to the answers.
Yes, every material absorbs and releases heat.
The interesting bit here is something different though. I have never seen that someone wants to use a phase change material for buildings, but why not? For coffee cups this already works nicely. The walls of the mug contain a material that is undergoing some phase transition (liquid to solid, different crystalline structure, magnetic, etc.) at a temperature that is slightly below really hot coffee but still a nice drinking temperature.
What happens is the following: the thermal energy of the coffee gets absorbed quickly by the material, therefore cooling it down fast from really hot to a lower temperature. The material can store a large amount of thermal energy and releases it slowly so that the coffee stays at a constant temperature for much longer (gizmag article).
For a whole building this makes a lot of sense as well. It more or less acts as a large thermal reservoir, so that your wall temperature does not increase during the day and falls too much during the night. You could achieve a somewhat similar effect by using 20 inch stone walls but this might be a bit easier to incorporate into modern buildings.
This is useful for maintaining a consistent temperature inside when the outside temperature is bouncing above and below the temperature of the phase change (say, between day-time and night-time) rather than always needing to heat when it's cold and cool when it's hot. The PCM "building material absorbs and releases heat" automatically, in theory lowering your energy bills.
The neat thing--and yes, this IS neat--is a) this material is tunable; you can set the phase transition temperature at time of manufacture and b) it doesn't turn into a liquid, but rather changes between two different solid phases, which is nice for things like, you know, walls, that you'd like to stay solid.
And you were all so excited by this idea when Wozniak was pushing it in 2007; he'd latched onto a certain species of wood whose sap underwent a phase change at 72 degrees. Build a house out of that, and it will tend to keep the inside temperature at a Woz-friendly 72 degrees.
Those who fail to understand communication protocols, are doomed to repeat them over port 80.
for thousands of years.
I wonder how much the material out gasses...
"If any question why we died, Tell them because our fathers lied."
Ice Nine
Link
http://www.nottingham.edu.cn/en/news/scientific-breakthrough-university-invents-heat-regulating-building-material.aspx
and article
http://www.sciencedirect.com/science/article/pii/S0196890410003729
Microscopic sprayed on layer will have microscopic heat storage capacity.
Is there a link to the story? The link in the summary doesn't seem to work.
These Phase Change Materials are different from other matter. They absorb heat without changing their temperature.
So as the heat energy increases in a room - say, when sunlight shines in a window, or hot air circulates in - the energy is absorbed by the PCM instead of heating the regular matter in the room. So the energy increases, but the room's temperature doesn't. Instead, the heat energy changes the phase of the PCM. So work is done by the energy, just not work that increases temperature. Which means a room can "heat up", but doesn't feel like it to people (or other things made of matter) inside.
Later, as heat leaves the rest of the room (outside temperature drops as Sun goes down, cold air enters, etc), the PCM phase changes back, releasing the heat energy into the rest of the room. The temperature of the room stays the same again, though there's less heat - the lower heat content of the PCM merely "relaxes" the phase to the lower energy phase.
It's exactly like the way that ice stays at 32F (0C) in your drink in a 70F room or a 90F beach, even as it absorbs heat from the drink and the surrounding air. So the drink and everything in the glass stays at about 32F (given convection in the drink around the ice), even though the total heat is increasing in there. The ice gradually changes phase, which consumes energy without its temperature rising. Until eventually it's 32F water when the phase change is complete. Then the temperature rises, because there's no phase change consuming energy.
Yes, it's thermodynamics. But unless you can invent a PCM that harnesses thermodynamics, you can't patent it. Unless maybe you're just a patent troll. They're immune to thermodynamics laws, and probably legal laws, too.
--
make install -not war
This material is consuming heat energy to perform the work of dis/organizing its molecules without its temperature increasing. That sounds like a (maybe just nearly) perfect nanomachine powered by heat. If the mechanical work can be powered by heat to do useful matter movement, like microfluidics or even nanoassembly, we might have found a device that can use our too-abundant waste energy (heat) for some of our most useful tasks: chemical manufacturing. Maybe even nanocomputing, pushing molecular rods or fluid transistors.
Any way you look at this stuff it's exciting. Revolutionary. If it's cheap and nontoxic, the whole world could pivot on this stuff the way it did on the steam engine.
--
make install -not war
welcome to thousands of years ago
Very similar systems are being developed to aid A/C units in cars with stop/start engines: http://www.sae.org/mags/aei/9864
You can fix anything with duct tape and sticks.
Since when did this international campusing became the vogue?
U. California Los Angels at Shanghai anyone?
http://www.micronal.de/portal/basf/ien/dt.jsp
You can buy mortar, cement, bricks and similar stuff with this stuff in it for years now, so this is hardly news. But it is a great material:
Essentially, you can create a building that behaves like a heavy building in summer (eg. only very slowly heating up after a cool night)
and like a light building in winter. (quickly heating up after reducing the temperature at night to reduce energy loss)
The material absorbs very little heat below a set temperature (e.g. 24C) and then suddenly requires great amounts of energy to heat up
any further.
How is this "invention" different from the established product BASF Micronal which has been available for a couple of years?
http://www.basf.com/group/corporate/en/brand/MICRONAL_PCM
This looks all quite well and promising, but there are no numbers. I wonder how much more heat capacity this material has wrt, say, brick or water.
Yeah, I know, Infinite! It's a phase transition where the temperature doesn't rise at all with heat added. Or rather, close to infinite (sorry, my fingers ache as I write this, but I hope you get the idea). I remember measuring spikes in Cp and Cv for hours and hours in undergraduate physics lab, and plotting it out on millimeter grid paper with a pencil. Ah, those were the days...
Where was I? Yes. How much more heat can this material take without heating up? Does it keep the temperature at 20C instead of 35C? Or at 20C instead of 21C? I know it depends on various factors like amount of material, size of room etc., but an example would be great.
Say out loud: I'm an Aspie and I'm somewhat proud, I guess. Uh. Can I write an email in all caps instead? Hm...
I suppose it is the non-deformable and tunable aspects that are novel.
There's a story about National Gypsum out of North Carolina having this stuff back in 2/4/2010. So, this is not new. My guess is, the Chinese stole it.
After i finished spray painting my sky scraper with all my solar cell paint to catch all the light and heat ....now i can spray paint another coat on top of it, and have duplicate layer technology that will allow for me to have more heat or less, and still give me my electricity?
Suppose that this material had a phase change specific heat comparable to the liquid/solid change of water. 330 kJ/kg.
By comparison the specific heat of water is only 4 kJ/kg
Let's consider a house 20x40 feet with R30 walls and an R40 ceiling.
It has 120 linear feet of wall x 8 feet high so it has roughly 1000 square feet of wall. At R30 that's 33 btu//hr/F. The ceiling is 800 square feet at R40 so it's 20 btu/hr/F. So our cute windowless box takes 53 btu/hr/F
In 12 hours it will use 640 btu/F. I chose 12, figuring that the temperature would spend half the day being too hot, and half being too cold. Hmm. Two kilograms per degree F. It would take 160 kg of water to do the same thing with a 2 degree F fluctuation in temperature
If we assume a desert climate that averages nice, but has a 20F on either side of nice, now it takes 40 Kg of this wonder material.
Now that specific heat is too high by a factor of 3 or so.
Now we are up to 120 Kg.
And the heat/cooling load of a typical building is evenly split by the insulated walls and the windows. (Windows are normally 10% of floor area, but have 10-15 times the heat transmission unless you go high tech.)
So that adds a factor of 2. 240 kg.
In a heating environment air changes are ususallly responsible for another factor of 2 in heating. This can be reduced considerably by using a heat recovery ventilator. But lets be passive.
500 kg of wonder stuff.
I started out this note to show that it was unreasonable to do this. It looks quite feasible.
A sheet of gypock is, what, a kg/square foot. A house typically is 2 rooms thick, so it has 2000 square feet of wall gyprock, and 800 square feet of ceiling gyprock. So if roughly 20% of the gyprock mix were wonder stuff, it could handle a 20 degree excusrion on either side of nice.
However, it would make for an awfully thick layer of paint.
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That is why gypsum drywall is used, right? As a fire tries to heat it, the captive water is evolved out as steam. With some luck, it slows the fire's spread long enough that you get out of the building.
Oh, I'm sorry sir, I thought you were referring to me, Mr. Wensleydale.