According to New Scientist, phase change materials - materials that melt at around room temperature - could revolutionise the way we cool our buildings.
The sun has risen, and a new building on the University of Washington’s campus in Seattle is slowly melting. Or at least parts of the building are anyway. Encapsulated within the building’s walls and ceiling panels is a fabric specially designed for climate regulation, called a phase change material (PCM).
The material – a gel, which New Scientist reports on in its 7 January issue, melts at around room temperature, and while melting absorbs lots of energy, helping the building stay cool. At night, when the temperature drops, molecular bonds within the gel are reformed and the material thus releases heat (which can easily be dissipated by opening the windows). The material is then being ‘recharged’.
Professor Andy van den Dobbelsteen, of the climate design and sustainability section (Architecture faculty), is familiar with this technique. “The materials are not being used much yet,” he says. “A lot of research effort is being put into optimizing these kinds of materials, however. They’re still very expensive, but as developments continue prices will drop.”
The professor believes the technique is especially promising for building light-weight constructions. Regarding their thermal behaviour, PCMs are in fact a kind of light version of rock and concrete, Prof. Van den Dobbelsteen explains: “Heavy buildings, like Romanesque churches, also stay cool thanks to the materials they’re made of. Their thick walls have a high thermal mass which helps to reduce indoor temperature fluctuations. What’s interesting about PCMs is that you can regulate the temperature using a lot less material.”
PhD student, Bas Hasselaar (Architecture faculty), agrees. But he also warns that PCMs are not the panacea they’re often taken for. “These materials can only help in fine tuning the temperature,” explains the researcher, who extensively studied the materials for his thesis. “PCMs do not have very high thermal mass overall, yet during their melting trajectory their heat absorbing capacity peaks. Once the temperature has risen above that melting range, say 25 ºC, they no longer cool the building.”
Another disadvantage of PCMs is that they do not have any supporting power, says Hasselaar. Consequently, one must always encapsulate them in other building materials.
If you want to make a building in which the climate is regulated energy efficiently, you have to set your priorities differently, Hasselaar concludes: “First of all, you need good sun blinders, you must ensure the building is constructed with material that has lots of thermal mass, and you need good ventilation. When these requirements are met, then you can wind up with PCMs.”
“There’s lots of outrage among Dutch students right now about proposed changes to the university tuition fee structure. Because the public coffers are empty, the government is looking for ways to balance its budget. One proposal is to raise tuition by €3,000 for students studying in their seventh year or beyond at university. Students are outraged, because no one likes having things taken away from them. But not only is this not as bad as Dutch students might think, it might actually be better.
While €4,700 sounds like a lot of money, try telling that to international students, who’ll pay €12,500 at TU Delft next year, and between €14,200 and €19,100 at Leiden University. And that’s for every year of our study, not just the seventh year! Plus, university is both a both personal and professional investment. University grads earn substantially more than those without degrees, and even if you take an extra year to finish your studies, the Dutch government lets you repay your loan at 1.5% interest.
Forcing Dutch students to consider what they really want to study, why they want to study and how they’ll finish ‘on time’ could in fact be better for everyone - not just the government’s budget. If Dutch students know they must pay more to study longer, they might take some time off before university to work, create, travel…or any other pursuits that helps give perspective to life and what one wants out of it. In the US, as in Holland, people traditionally go straight to university after high school, which isn’t the best choice for many people. If students are forced to be more serious about their studies, maybe it’ll force more introspection, and maybe there won’t be so many Dutch students who say: ‘If you get a 7, you studied too hard’. In other words, maybe a study ethic will rise.
If you’re going to complain, then at least bring constructive alternatives to the table: it’s a much better way of bargaining than simply giving the government the middle finger. After all, the cuts aren’t because the government is evil, but because they’re backed into a budgetary corner. For example, I went to school in Washington state, where students pay between $800 and $6,000 per year in tuition, depending on your income. If your family is low-income, you actually get paid to go to school. If your family is wealthy, you pay the full amount. If you’re somewhere in between, you pay in between. Not only is this type of payment schedule more equitable for everyone than a flat rate, but it benefits the government’s budget as well.Of course, no one wants to give up something they have, but it’s also true that Dutch youth can no longer be students until they’re 30 at the same time as old people also want the government to pay for everything. So to all my Dutch friends, don’t be sad, you still have it pretty good. At least you don’t get suckered into paying €400 a month to live in a motherf*#%ing spacebox! But that’s a subject for another column.”
Devin Malone, a second-year MSc student of industrial ecology, is from Anchorage, Alaska.