130605 levitt thermal autonomy.ppt
TRANSCRIPT
Brendon LevittLoisos + Ubbelohde, Alameda, CaliforniaUniversity of California, BerkeleyCalifornia College of the Arts, San Francisco
M. Susan UbbelohdeLoisos + Ubbelohde, Alameda, CaliforniaUniversity of California, Berkeley
George LoisosLoisos + Ubbelohde, Alameda, California
Nathan BrownLoisos + Ubbelohde, Alameda, CaliforniaCalifornia College of the Arts, San Francisco
Thermal Autonomy as Metric and Design Process
AUTONOMOUS BUILDING
Boards, .............................. $8.03½ mostly shanty boards.Refuse shingles for roof and sides, ... 4.00Laths, ................................ 1.25Two second-hand windows with glass, ... 2.43One thousand old brick, ............... 4.00Two casks of lime, .................... 2.40 That was high.Hair, ................................. 0.31 More than I needed.Mantle-tree iron, ..................... 0.15Nails, ................................ 3.90Hinges and screws, .................... 0.14Latch, ................................ 0.10Chalk, ................................ 0.01Transportation, ....................... 1.40 I carried a good part
on my back.In all, ............................. $28.12½
I got out several cords of stumps in
plowing, which supplied me with fuel
for a long time... The dead and for the
most part unmerchantable wood behind my
house, and the driftwood from the pond,
have supplied the remainder of my
fuel."
FIRST YEAR’S HEATING BUDGET:
50% OF CONSTRUCTION COST
AUTONOMOUS BUILDING
“The next winter I used a small
cooking-stove for economy, since I
did not own the forest.”
THE MODERN BUILDING
Sketch by LeCorbusier, 1930
ENERGY USE AS METRIC
BASELINE OPTION 1+7.15%
OPTION 2-0.16%
OPTION 3-7.42%
Sketch by LeCorbusier, 1930
kWh/
m2
ENERGY USE AS METRIC
BASELINE OPTION 1+7.15%
OPTION 2-0.16%
OPTION 3-7.42%
Sketch by LeCorbusier, 1930
• does not show occupant comfort
• does not show daily patterns
• does not show seasonal patterns
• does not show when or if systems can be turned off
• does not consider free-running or mixed mode operation
• does not question comfort assumptions
• does not question scheduling assumptions
• does not question mechanical systems assumptions
• undervalues how the building envelope filters the environment
kWh/
m2
SHACK IN THE WOODS
Envelope Performance LOW
Energy Use NONE
Occupant Comfort LOW
BUSINESS AS USUAL
Envelope Performance LOW
Energy Use HIGH
Occupant Comfort MEDIUM
THERMALLY AUTONOMOUS BUILDING
Envelope Performance HIGH
Energy Use NONE
Occupant Comfort HIGH
HIGH PERFORMANCE BUILDING
Envelope Performance HIGH
Energy Use LOW
Occupant Comfort HIGH
Credit: Eric Kilby
THERMAL AUTONOMY AS METRIC
percent of a year that occupants feel thermally comfortable through passive means only
THERMAL AUTONOMY :: THE DASHBOARD
percent of a year that occupants feel thermally comfortable through passive means only
TA = 86%
THERMAL AUTONOMY :: THE DASHBOARD
• weighted degree hours
• number of occupied hours
• percent of occupied hours
• histogram of annual distributions
• diurnal / seasonal patterns
TA = 86%
THERMAL AUTONOMY :: THE DASHBOARD
• weighted degree hours
• number of occupied hours
• percent of occupied hours
• histogram of annual distributions
• diurnal / seasonal patterns
TA = 86%
THERMAL AUTONOMY :: THE DASHBOARD
• weighted degree hours
• number of occupied hours
• percent of occupied hours
• histogram of annual distributions
• diurnal / seasonal patterns
TA = 86%
THERMAL AUTONOMY AS METRIC
lends itself to understanding:• envelope as environmental filter• Influence of internal loads• an intuitive focus on occupant comfort• assumptions of comfort, schedule, and systems selection• gentle failure• reduction of active systems• extended free-running periods
TA = 86%
... AS DECISION-MAKING TOOL
... AS DIAGNOSTIC TOOL
... AS DESIGN TOOL
FREMONT HIGH SCHOOL OAKLAND, CA
Credit: CAW Architects
... AS DECISION-MAKING TOOL:
“Do we need air conditioning?”
TA = 10%
NATURAL VENTILATION
TA = 81%
NATURAL VENTILATION
+ NIGHT FLUSH
TA = 65%
NATURAL VENTILATION
+ NIGHT FLUSH
+ OPERATING HOURS ONLY
12
3
6
9
12
457
8
1011
TA = 86%
TA = 86%
BASE SCHEME
OPTIMIZED SCHEMETA = 86%
TA = 10%
“Do we need air conditioning?”
BASE SCHEME
OPTIMIZED SCHEMETA = 86%
TA = 10%
YES!!!!
“Do we need air conditioning?”
maybe not
PIER 27 FERRY TERMINALSan Francisco, CA
Credit: America's Cup Event Authority
... AS DESIGN TOOL
“What is the role of shade?”
THERMAL AUTONOMY:
3%
THERMAL AUTONOMY:
13%
THERMAL AUTONOMY:
3%
THERMAL AUTONOMY:
96%
THERMAL AUTONOMY:
3%
THERMAL AUTONOMY:
97%
THERMAL AUTONOMY:
3%
THERMAL AUTONOMY:
3%
PRIVATE RESIDENCESonoma, CA
Credit: Turnbull Griffin Haesloop
... AS PATTERN-RECOGNITION TOOL
“When is it too hot?”
INITIAL DESIGNTA = 57%
BETTER GLASSTA = 59%
UNINSULATED SLABTA = 56%
AIR MOVEMENTTA = 68%
VERY HOT
VERY COLD
Thermal Autonomy: 12%SHACK IN THE WOODS
Thermal Energy Use: 315 kWh/m2BUSINESS AS USUAL
Thermal Autonomy: 12%THERMALLY AUTONOMOUS BUILDING
Thermal Energy Use: 82 kWh/m2HIGH-PERFORMANCE BUILDING
FUTURE RESEARCH
• Area- vs. occupancy-weighting in multi-zone buildilngs
• Benchmarking for different climates, building types, thermal comfort standards
• Benchmarking relative to Energy Use Intensity
• Tool for Mixed Mode operation scheduling
BRENDON LEVITT[[email protected]]
Loisos + Ubbelohde, Alameda, California
University of California, Berkeley
California College of the Arts, San Francisco