p i n u p s p a c e » teaching

psychrometrics with Matlab

ted — Sun, 27 Feb 2011 21:08:36 +0000

This is the second tutorial on climate visualization using Matlab, particularly on plotting weather data on a psychrometric chart.

Although architects are most familiar with psychrometric chart to understand comfort zone and identify appropriate passive design strategies, psychrometrics is more commonly used by mechanical engineers to study air and water vapor mixture for active mechanical devices to condition air.

Tools like Autodesk’s Ecotect Weather Tool or Climate Consultant are typically sufficient for architects to study comfort zone and passive design strategies. However, for active applications, we need to be able to enter our own data points, such as ones that come from mechanical specs or material properties.

4 scripts 2 data files are included in this distribution.

Make sure all 6 files are mapped into your Matlab path. Easiest way is to put all the files into your My Documents\Matlab folder, or on OSX > Documents\Matlab
Open ReadEPW.m This is an updated version and does not require you to manually input the file path.
Click Run and locate the desired Energy+ Weather file
Open EPW2Hourly.m and click Run
Type in command:
psychro(dbt,ahm,0,0,’scatter’);
This will create a scatter plot of all the hourly values of dry bulb temperature and absolute humidity.
To separate all the data by months, use the command
psychro(dbt(aug),ahm(aug ),0,0,’scatter’);

psychro(dbt(apr),ahm(apr),0,0,’scatter’);
Sometimes having all the hourly data is not very useful because there’s simply too much information. Run the EPW2Daily.m file, this will reshape the 1×8760 matrix to 24×365, and we can easily find the daily maximum and minimum, and plot the diurnal changes.
Type in command:
psychro(dbtMax,dbtMin,ahmMax,ahmMin,’line’);
This will give you a line plot of all the diurnal changes. The line will start at the higher temperature and end at the lower temperature.
Once again, we can separate it into individual months with the following command
psychro(dbtMax(aug),dbtMin(aug),ahmMax(aug),ahmMin(aug),’line’);
psychro(dbtMax(apr),dbtMin(apr),ahmMax(apr),ahmMin(apr),’line’);

If you get an error like this one

??? Error using ==> fgetl at 44

Invalid file identifier. Use fopen to generate a valid file

identifier.

Error in ==> ReadEPW at 16

loc = fgetl(fid);

That means Matlab is not recognizing the folder of your EPW file. Go to File > Set Path and locate the folder.

To set a different color for each month and automatically save the charts, you can do the following.
%written and copyrighted by Ted Ngai www.tedngai.net %version 0.1 Mar 2011


xSize = 6; %This is the horizontal size of the figure

ySize = 4; %This is the vertical size of the figure

months = {1:31, 32:59, 60:90, 91:120, 121:151, 152:181, 182:212, 213:243, 244:273, 274:304, 305:334, 335:365};

monthstr = {'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug', 'sep', 'oct', 'nov', 'dec'};

figure;

c=0;

for x = 1:12
    %get current month

    month = cell2mat(months(x))';
    %get min/max of month

    maxmon=max(month);

    minmon=min(month);
    %set color value

    nColor=[1,0.8-c,0.1+c];

    c=c+0.07;
    %plot graph

    psychro(dbtMax(month),dbtMin(month),ahmMax(month),ahmMin(month),'line',nColor);
    xlabel(cell2mat(monthstr(x)));  %.. and label for the y axis

    %ylabel('temperature (\circC)');   %Input the labels for the x axis
    currentFig = gcf;

    currentAxes = gca;
    set(currentAxes,'FontSize',6);

    set(currentFig, 'PaperUnits', 'inches'); %change paperspace units here (also line 25)

    set(currentFig, 'PaperSize', [xSize ySize]);

    set(currentFig, 'PaperPositionMode', 'manual');

    set(currentFig, 'PaperPosition', [0 0 xSize ySize]);

    set(currentFig, 'Units', 'inches'); %change paperspace units here too

    set(currentFig, 'Position', [0, 0, xSize, ySize]);
    axis([minmon maxmon 0 120]);
    fn=['psychro_daily_',city,num2str(x),'.ai'];

    hgexport(currentFig,fn); %Change the filename here

end clear xSize ySize currentFig currentAxes fn temp maxmon minmon month ;

Ecophysiological Architecture

ted — Mon, 21 Feb 2011 03:57:01 +0000

Through evolution, animals and plants develop strategies to survive and thrive in their own environments. Survival mechanisms such as thermoregulation, water economy, and energy metabolism, are common to all organisms. Physiology, since the famed French scientist Claude Bernard, has become the study of how such mechanisms manifest under isolated and controlled conditions. Ecophysiology, on the other hand, pursues the studies in the subject’s own environment and allow for a much more natural observation and analysis of the organisms’ responses to the dynamics of resource availability and diurnal and seasonal switches. Architecture, often conceptualized as the third skin, can learn much from such physiological approach, particularly in the face of global climate change and energy crisis. Unlike conventional architectural practice, organisms do not deal with heliotropism separately from thermoregulation, nor would do they handle water economy separately from energy conservation and metabolism. To maintain a stable internal environment, organisms must rely on everything at their disposal as part of their survival strategy. Therefore, ecophysiological architecture posits the same fundamental basis and asks a simple question: “what if buildings have to develop heating, cooling, lighting, daylighting, and ventilation strategies as part of its morphology?”

The following are selected works from a studio investigation that attempts to reapply these highly coupled physiological systems with the building’s mechanical and morphological system to imbue a behavioral solution to address the ecology of our built environment.

Projects

Joe Hines | Active Thermoregulation

Shima Miabadi | Counter Current Heat Exchange

Nicholas Stipinovich | Wind Responsive Envelope

Lauren Thomsen | A Photoperiodic Envelope

Adam Petela | Adaptive Networking

parametric design workshop 2010

ted — Sun, 14 Nov 2010 17:33:08 +0000

Here are some selected images of a 5-week design workshop held by and Rensselaer Polytechnic Institute School of Architecture and the Politecnico di Torino Faculty of Architecture II.

Design approach is based on the ecophysiology of animals. Students research and analyze an animal’s mechanism for thermoregulation, photoperiodism, water economy, and other energetics exchange, and develop an architectural integumentary system that deals with heating, cooling, ventilation, and lighting, which, when combined, accounts for almost 70% of all electricity consumption in the US.

Extensive parametric and analysis tools are used for the design of these projects, all of them can be found on my website here.

Workshop Instructors
Ted Ngai, RPI
Cesare Griffa, PoliTo

Workshop Coordinator
Graziella Roccella, PoliTo

Workshop Description
The parametric workshop engages the problems raised by our rapid pace of urbanization and the ecological impact of our built environment, using two main drivers: the evolving of digital technologies, and the growing of ecological awareness.

Digital technology plays a critical role in acknowledging change and difference in the way we design, build and live architecture. Ecological awareness, on the other hand, requires one to observe and understand the behavioral tendencies of our natural and built systems. The use of parametric design software in this context will enable designers to use design not only as an organizational device serving semiotic, pragmatic and aesthetic functions, but also as a regulator of the internal and external environments, managing bioclimatic flows to maintain homeostasis through intelligent morphologies.

In this framework, the workshop program will develop a Physiological Skin, a concept that explores the “envelope” as a mean to capture, transform, store and distribute various energetic flows to maintain a stable internal environment appropriate for housing in the city of Torino.

The Physiological Skin will not only take on the bioclimatic exchange as its main design challenge, but will also consider the aesthetic vision as it is situated in the historical Italian neighborhood. This includes addressing the Renaissance and Baroque, and times of new discoveries and new aesthetics, which will also be main criteria for the successful development of the project.

Projects:

(RE)TENDER | John Baker | Frank Florian | Chris Nobes | Salvo Terranova

ADAPTIVE RESPIRATION | Marco Caprani | Alexandra Dorn | Cesar Madrigal | Andrea Terreno

SUSTAINA(BUBBLE) | Alyssa Johnson | Christos Constantinou | Giulia Mondino | Marco Palma

ALGaeRITHM | Monica Cazzamani Bona | Jillian Crandall | Nathalia da Rosa Pires | Tyler Hopf

AQUALIBRIUM | Angie Ohman | Sarah Murray | Marina Milia | Matteo Miroglio

PASSIVE FLOWER | Christine Koch | Alicia Miksic | Matteo Tron

SHARK SKIN SMART SKIN | Davide Speranza | Evelina Micono | Kate Lisi | Kateri Knapp

BARE NECESSITIES | Matteo Amela | Gianni Bruera | Morgan Danner

surface | skin | structure

ted — Sat, 30 Dec 2006 01:56:28 +0000