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High Performance Building Design

CIV_ENV 395 Week 4: Comfort & Façade Design

October 9, 2017

Comfort

• Visual Comfort

• Thermal Comfort

http://www.archdaily.com/773066/search-ends-for-solution-to-museum-towers-glare-problems-at-nasher-sculpture-center

http://www.archdaily.com/773066/search-ends-for-solution-to-museum-towers-glare-problems-at-nasher-sculpture-center

Image Credits: Nicole L. Peterson

Supplemental blinds were

added in front of perimeter

office space after occupancy

Daylight Analysis

Image Credits: Nicole L. Peterson, The space between research and practice: A critical evaluation of computer-based lighting metricshttp://dmg.caup.washington.edu/pdfs/Thesis.NicolePeterson.2015.pdf

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ics

Comfort

• One way to achieve visual AND thermal

comfort is external shading

• What about internal shading?

• How do we optimize this?

Sun Path Diagrams

Sun Path Diagrams

Sun Path Diagrams

Months

Sun Path Diagrams

Analemma:

Hour

Sun Path Diagrams

Sun

Altitude

Sun path diagram

Building Façade Shading Cut-off AnglesSouth façade at noon

Building Façade Shading Cut-off AnglesSouth façade at noon

h

June 21 @ noon: ?

September 21 @ noon: ?

December 21 @ noon: ?

x ?

Getting sun angles:

• Analog

• Ecotect

• Grasshopper + Ladybug

Rhino / Grasshopper plug-ins

Rhino / Grasshopper plug-ins

Hammer vs. Swiss Army Knife

Ladybug

Ladybug

Ladybug

http://www.grasshopper3d.com/group/ladybug

Links:

• Ladybug homepage:http://www.grasshopper3d.com/group/ladybug

• Intro video series by MostaphaRoudsari:https://www.youtube.com/watch?v=9_u0dnyq2QI

• Intro video series by Chris Mackeyhttps://www.youtube.com/watch?v=8UFkJL-aZy8

• Ladybug video seminar: https://vimeo.com/ondemand/performancenetwork/180282919?autoplay=1

Ladybug

https://hydrashare.github.io/hydra/

LadybugSearch!

Building Façade Shading Cut-off AnglesSouth façade at noon

h

June 21 @ noon: ?

September 21 @ noon: ?

December 21 @ noon: ?

x

• Which timeframe is shading necessary?

e.g. summer only? + some shoulder seasons?

• Solve for overhang depth, x

(or solve for h if you know what you want x to be)

• Think about your climate, program, what proportions

make sense, window head heights, etc.

• Remember: this is only for the South façade

• We use this as a starting point, and then move to

analysis to understand the daylight and glare

conditions inside

Trigonometry + Excel:

tangent = opposite

adjacent

tan = h

xx =

h

tan

Building Façade Shading Cut-off AnglesSouth façade at noon

h

June 21 @ noon: ?

September 21 @ noon: ?

December 21 @ noon: ?x ?

Maybe you have horizontal louvers

rather than an overhang -> shading masks

Building Shading

Remember these rules of thumb:

This is not just for visual comfort, but also

for thermal comfort. Remember – external

shading blocks solar gains from the façade.

We will talk more about thermal comfort

next class.

Solar Radiation Maps: Example

Solar Radiation Maps: Demo

What about our building,

2020 Ridge?

Solar Radiation Maps: Demo

N

Solar Radiation Maps: Demo

But what does this mean?

This is for you to figure out in your homework.

Remember to always include a legend with units / north arrow – it is meaningless without it !

Use an appropriate scale to show a gradient & differences between façades.

Overshadowing: Example

Shadow Studies: Example

Façade design

Where do you want to place windows based on orientation, program, etc?

• Think about punched openings vs curtainwall

• Potential focused work: glass design, daylight simulations

Apple Store – New York City

http://www.apple.com/retail/fifthavenue/

David Zwirner Gallery – New York City

http://www.forbes.com/sites/tamarawarren/

2013/01/29/david-zwirner-opens-new-manhattan-gallery/

Glazing properties

• With better thermal insulation, it may be possible to have a higher glazing

percentage; U-value and WWR are tradeoffs that can be balanced to

achieve optimal overall energy performance.

• For cold climates: There are cases where triple glazing has eliminated the

need for perimeter heating. Better performing glass can also result in less

drafts.

• Think about how all of this comes together in low-E coatings, frit, glazing-

integrated PVs, and electrochromic glass.

Glazing properties: considerations

Glazing properties: considerations

Glazing properties: considerations

Assignment #4:

Comfort / Façade Design

Assignment #4: Façade / ShadingOverall goal:

Begin thinking about your façade design & what shading strategies you will implement.

1. Shading cutoff calculation

Perform a shading cutoff calculation with the method of your choice. Document it fully.

• If you were to implement horizontal shading elements on the south façade, how deep

would you make them and why?

• Are you planning for overhangs, lightshelves, louvers, a combination, or none of these?

2. Solar radiation map

Given the solar radiation results, display your findings in whatever format you like.

You must explain the following:

• Do you think our building’s orientation is optimal?

• Note the differences by façade and begin thinking about corresponding strategies. Each

façade should be represented using graphics & text (you can use axonometric views).

e.g. The north façade has an average solar radiation of 500 kWh/m2, and should be the target.

The West has an average solar radiation of 1200 kWh/m2, and we plan to use automated

venetian blinds to reduce it down to the target.

3. Based on 1 & 2, begin mapping out where you plan to have windows and what shading strategy you

will use. You can use whatever medium you like e.g. Rhino model, sketches, etc.