Pages

22.10.11

The Laws of Thermodynamics and Their Implications on Thermal Comfort in the Built Environment

The Second law of thermodynamics is the most prevalent for the explanation of heat uses within dwellings; it describes the natural direction of energy transformation and entropy. Energy “…move[s] from a highly ordered state to a disordered state…” (Cleveland, Kaufmann 2008.) Heat, as the form of energy with the most entropy, is the eventual natural result; “Entropy of a closed system increases (more exactly, does not decreases) with time.” (Prisyazhniuk, 2007.) This heat will spread until it reaches equilibrium. Within buildings this means that a source of heat, whether it be a fire, hot water system or direct solar gain will spread itself from the concentrated source point out towards any cooler area. Ideally for thermal comfort this heat energy, once within the space should be conserved, emphasizing the importance of airtightness and insulation in design as well as the importance of space economy, or: not wanting to spend the energy to heat to near equilibrium a large space, for just one person. The second law also describes how in order to produce a useful lower entropy, (highly ordered,) form of energy; the kind needed in order to generate heat within our home, that additional energy has to be applied and work done. (Prisyazhniuk, 2007.)  “…the continuous flow of oil, coal, and other fuels used to run society is converted into low quality, unavailable energy ("waste heat").” Also described by the ‘Zero’ law, “…All bodies acquire the temperature of the environment…” (Prisyazhniuk, 2007.)[1] Such laws explain the difficulty of conserving and storing energy as heat, a continuous battle against natural physics that appears to be one of the main elements of environmental dwelling design. We try to harness the high entropy form of energy to store for times when the natural pulsing environment has spread the availible warmth to near equilbrium at a localized area, working with these rules and using the importance of temperature difference to control passive heat flow we endeavour to slow the enevitable directional movement of energy for our comfort.



[1] The "Zero" Law of Thermodynamics: the Law of Heat Equilibrium, this wording is put by J. Black (1728 – 1799): "All bodies freely communicating with one another and not subject to a non-equilibrium impact of the ambient conditions acquire one the same temperature, as determined with the thermometer. All bodies acquire the temperature of the environment."(Prisyazhniuk, 2007.)

17.10.11

Module one – Professional Diploma in Architecture (AEES)

The past week has been unlike any other, as the 22 Prof Dip fresher’s travelled to CAT from all over the country to meet for our first meal together on Monday night in the WISE building. The tutors didn’t waste any time and started us off that evening discussing the ‘sacred cows’ of sustainability with the MSc students to challenge our preconceptions and ideologies on sustainability from a wide variety of points-of-view through role-playing.

We were really looked after at CAT, with delicious food, 3 large meals a day, teas, coffees, juices and wine. This week we were sleeping in the WISE building itself, enhanced by our lecture about the building design by David Lea. We stayed 2 to a room in the wonderfully tranquil bedrooms, timber clad, with a floor to ceiling, square glazed screen that slid open directly onto the roof top terrace, looking down to the ‘drop-pool’ courtyard and out to the west Wales mountains.
The first module took us through some information-packed lectures, from Nick Baker: “…intercepting natural cycles of CO2 for human use…”, Peter Harper: “Physics trumps Politics…is true although our whole economic and societal systems are based on entirely the opposite…” To Ranyl Rhydwen, jumping up and down on stage, electrically retelling in quick rhythms the proofs of future doom caused by humanity, then following on in a subsequent lecture “human adaptation/transformation for climate change, opportunity and a change in fundamentals…” renewing students hope, energy and ideas for our learning to design future places. Evening lectures included history of CAT and a visiting lecturer: Roddy from Ted Cullinan architects.

Studio time this week initially made us take a look at our design approach and write a manifesto to be presented in one minute, then, we were taken through a drawing journey with Trevor Flynn of ‘Drawing at work’ who ran a drawing gymnasium. It began in the hills at CAT trying to measure and draw the 5th year’s Bird Hide. This twisting, free flowing form built from standard sized timber all felled within 500metres of the site, proved incredibly difficult to work out in the mind’s eye, due to the shapes and shadows of its morphic appearance. Despite this, with Trevor’s help, freehand oblique, section, isometric, one and two point perspectives appeared before us.

Saturday bought the roundup of the drawing session in the WISE building and a site visit for design project 100.1. This was followed by a traditional evening for the postgrad students: a social with a theme, everybody became their pirate alter ego, drinking rum and playing crew games, wearing elaborate costumes and props created from any material to hand in an old slate quarry. Not sure if anyone remembers which team won…but I do remember the fantastic atmosphere in the bar, the hot wood sauna in the hills and the cool fresh waters of the reservoir lake…

We finished with a Sunday morning of thought provoking lectures, Richard Hammerton: ‘Humans in context: Environmental change’ and Tanya Hawkes: ‘Policy responses to climate change’. The general consensus at the end of week 1 from the Prof Dip student’s is that there is nowhere quite like CAT to study and we are very glad we’re here. We are inspired, very tired, bonded as a group, filled with optimism and can’t wait to get started on the rural housing project based in Machynlleth, sketch books ready, roll on the next week at CAT…