Energy and comfort modeling for the net zero rocky mountain institute headquarters

Energy and Comfort Modeling for the Net Zero Rocky Mountain Institute Headquarters

August 19, 2015

BUILDING ENERGY SIMULATION FORUM

Marc Brune, Ben Burnett, John Breshears

Amory B. Lovins:

Oxford Don

MacArthur Fellow

Early green building theorist (Lovins Green Home, 1983)

Energy policy strategist (“The Soft Path” and others)

Founder, Rocky Mountain Institute (1982)

“At Rocky Mountain Institute we are practitioners, not theorists. We do solutions, not problems. We do transformation, not incrementalism.”

- Amory Lovins, RMI

Project Visionary

Project Goals

1. LEED Platinum2. Living Building Challenge Petal Certification

1. Net Zero Energy2. Site3. Health4. Equity5. Beauty

3. Passive House Air Tightness Standards4. No Mechanical Systems5. Architecture 2030 Challenge goals (exceeded)6. Energy Star target score of 100

of commercial buildings are under 25,000 SF

90%are the biggest use of commercial buildings under25,000 SF

Officesof commercial buildings under 25,000 SF are owner occupied

Half

By 2035, about three-fourths of U.S. floor space will be new or renovated.

Project Replicability

RMI

BASALT

LIBRARY

RFC

DOWNTOWN

BASALT

TOWN HALL

TOWN GATEWAY

North

Town Park / River

Two Rivers Road

Pro

pe

rty L

ine

Town Park / River

Park Access

Park Access

North

Two Rivers Road

Town Access

View

North

Image courtesy of ZGF Architects LLP

Image courtesy of ZGF Architects LLP

R-132x4 wall with battinsulation

R-2.6 Window code minimum.

Solarban70XL

Energy Goals

HVAC Systems: Geothermal

HVAC Systems: Solar + Air Source

HVAC Systems: Just Air Cooled

HVAC Systems: No Cooling, Electric Heating

0

200

400

600

800

1000

1200

1400

HO

URS

TEMPERATURES

Temperature and Humidity Plot, Aspen, CO vs. Portland, OR

(TMY3 Data)

All Hours

0 to 20 RH 20 to 40 RH 40 to 60 RH 60 to 80 RH 80 to 100 RHPortland

Climate

[+]

[-]

Cost-Effectiveness Limit

DETOUR

Cumulative Energy Savings

Tunneling through the cost barrier…

…to even BIGGER and cheaper energy savings

Marg

inal Cost

of Eff

icie

ncy I

mpro

vem

ent

“Natural Capitalism” by Amory Lovins, 1999

Tunneling Through the Cost Barrier


DESIGN TARGET UNITS EXISTING (U.S.) BETTER BEST PRACTICE RMI DESIGN

Delivered energy intensity kBTU/sf-y 90 40-60 <30 17.2Lighting power density: connected load W/sf 1.5 0.8 0.4-0.6 0.49Lighting power density: as-used net of controls W/sf 1.5 0.6 0.1-0.3 0.27

Installed computers/appliances/tasklighting W/sf 4-6 1-2 <0.5 0.88Glazing R-value (center of glass) sf-F°-h/BTU 1-2 6-10 ≥20 12Window R-value (including frame) sf-F°-h/BTU 1 3 7-8 6.5

Glazing spectral selectivity* kₑ = Tvis /SC 1.0 1.2 >2.0 1.5-2.3

Roof solar absorptance and infrared emittance α, ε 0.8, 0.2 0.4, 0.4 0.08, 0.97 N/A, PV Covers RoofWhole-building airtightness cfm/sf @ 0.3" w.g. 1.0 0.4 <0.25 0.20

Installed mechanical cooling sf/ton 250-350 500-600 1,200-1,400+ None

Cooling design-hour efficiency** kW/ton 1.9 1.2-1.5 <0.6 0.00Level of installed perimeter heating - extensive minimal none minimal

*A measure of how well the glacing lets in light without heat

**Whole system, including pumps, fans, and cooling towers as well as chillers

ADDITIONAL DESIGN TARGET ITEMS

Wall R-value sf-F°-h/BTU R-50

Roof R-value sf-F°-h/BTU R-67 1

Window to wall ratio % 26%

Heat recovery effectiveness % 90% (Winter)

Installed mechanical heating BTU/h-sf 7.5 BTU/h-sf

1. Individual roof sections vary between R-40 and R-80 for different shapes and constructions. This value represents an area-weighted average.

This table (except for the "Additional Target Items") is from a Book entitled "Re-inventing Fire: Bold Business Solutions for the New Energy Era" by

Amory Lovins (2011). It is Table 3- "Benchmarking a New U.S. Office Building" (p. 108). These targets were developed by the Rocky Mountain

Institute and are typical of a new midsize -to-large Class A office in an average US climate like the Mid-Atlantic states.

DESIGN TARGET UNITS EXISTING (U.S.) BETTER BEST PRACTICE RMI DESIGN

Delivered energy intensity kBTU/sf-y 90 40-60 <30 17.2Lighting power density: connected load W/sf 1.5 0.8 0.4-0.6 0.49Lighting power density: as-used net of controls W/sf 1.5 0.6 0.1-0.3 0.27

Installed computers/appliances/tasklighting W/sf 4-6 1-2 <0.5 0.88Glazing R-value (center of glass) sf-F°-h/BTU 1-2 6-10 ≥20 12Window R-value (including frame) sf-F°-h/BTU 1 3 7-8 6.5

Glazing spectral selectivity* kₑ = Tvis /SC 1.0 1.2 >2.0 1.5-2.3

Roof solar absorptance and infrared emittance α, ε 0.8, 0.2 0.4, 0.4 0.08, 0.97 N/A, PV Covers RoofWhole-building airtightness cfm/sf @ 0.3" w.g. 1.0 0.4 <0.25 0.20

Installed mechanical cooling sf/ton 250-350 500-600 1,200-1,400+ None

Cooling design-hour efficiency** kW/ton 1.9 1.2-1.5 <0.6 0.00Level of installed perimeter heating - extensive minimal none minimal

*A measure of how well the glacing lets in light without heat

**Whole system, including pumps, fans, and cooling towers as well as chillers

ADDITIONAL DESIGN TARGET ITEMS

Wall R-value sf-F°-h/BTU R-50

Roof R-value sf-F°-h/BTU R-67 1

Window to wall ratio % 26%

Heat recovery effectiveness % 90% (Winter)

Installed mechanical heating BTU/h-sf 7.5 BTU/h-sf

1. Individual roof sections vary between R-40 and R-80 for different shapes and constructions. This value represents an area-weighted average.

This table (except for the "Additional Target Items") is from a Book entitled "Re-inventing Fire: Bold Business Solutions for the New Energy Era" by

Amory Lovins (2011). It is Table 3- "Benchmarking a New U.S. Office Building" (p. 108). These targets were developed by the Rocky Mountain

Institute and are typical of a new midsize -to-large Class A office in an average US climate like the Mid-Atlantic states.


0

200

400

600

800

1000

1200

1400

1600

Exiting (U.S.) Code Better Best RMI Target

sf/

Ton

Cooling Loads - InstalledMechanical Cooling in Buildings

0

10

20

30

40

50

60

70

80

90

Baseline Better RMI Target

BTU

H/S

F

Heating Loads – InstalledMechanical Heating in Buildings

RMI Electric Heating System

`

Air Temperature

Berkeley CBE Comfort Tool

http://smap.cbe.berkeley.edu/comforttool

http://smap.cbe.berkeley.edu/comforttool

Thermal ComfortPersonal Comfort System

Heat the people, not the space!

Thermal ComfortPersonal Comfort System

HVAC Systems:Designing the un-system

Energy ModelingIES Software

• IES calculates a complete energy balance for the building.

• This means: loads in IES are based on the actual resultant temperatures.

• Useful for Passive Analysis.

IES-VE

Glazing, High Gain Glazing, High Gain + Ext ShadesGlazing, Medium GainGlazing, Medium Gain + Ext ShadesGlazing, Low GainCurved SIP RoofFlat SIP RoofExterior WallPatio Roof

Glazing, High Gain Glazing, High Gain + Ext ShadesGlazing, Medium GainGlazing, Medium Gain + Ext ShadesGlazing, Low GainCurved SIP RoofFlat SIP RoofExterior WallPatio Roof

IES-VEShading Studies



-20

0

20

40

60

80

100

-20.00

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

20.00

25.00

30.00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Ou

tsid

e D

ryb

ulb

Te

mp

era

ture

(D

eg-

F)

Gai

n/L

oad

(B

tu/h

/sf)

Hour

Shading Scenario C Open Office Loadsum

Infiltration sensible gain

Glass solar gain

Lighting sensible gain

People sensible gain

Elec equip sensible gain

Underground floor conduction gain

Delayed roof conduction gain

Delayed wall conduction gain

Window conduction gain

Outside dry-bulb temp (F)

Space sensible load

IES-VENatural Ventilation – CFD vs. Bulk Airflow

SITE c o n d i t i o n s



Dominant Wind Direction,Summer Daytime - (upriver)

Dominant Wind Direction,Summer Night - (downriver)

IES-VENatural Ventilation – MacroFlo

IES-VENatural Ventilation – MacroFlo

IES-VENatural Ventilation - MicroFlo

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

0 22.5 45 67.5 90 112.5 135 157.5 180 202.5 225 247.5 270 292.5 315 337.5

Win

d P

ressure

Coeffic

ient

Angle of Attack

Custom Wind Pressure Coefficients

IES Semi Exposed Wall Custom South Window

IES-VENatural Ventilation - MicroFlo

IES-VENatural Ventilation – MicroFlo->MacroFlo

Sun Mon Tue Wed Thu Fri Sat Sun

4500

4000

3500

3000

2500

2000

1500

1000

500

0

Volu

me flo

w (

cfm

)

Date: Sun 18/Jul to Sat 24/Jul

MacroFlo external vent: 2-050 Open Office (Run A0 - Mod Weather Baseline.aps) MacroFlo external vent: 2-050 Open Office (Run A0 - Mod Weather Baseline-Winco.aps)



4500

4000

3500

3000

2500

2000

1500

1000

500

0

Vo

lum

e flo

w (

cfm

)

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

Are

a (ft²)


MacroFlo external vent: 2-050 Open Office (Run A0 - Mod Weather Baseline.aps) Eqv area: External window 1 (Run A0 - Mod Weather Baseline.aps)

MacroFlo external vent: 2-050 Open Office (Run A0 - Mod Weather Baseline-Winco.aps) Eqv area: External window 1 (Run A0 - Mod Weather Baseline-Winco.aps)



80

78

76

74

72

70

68

66

64

62

Te

mp

era

ture

(°F

)


Dry resultant temperature: 2-050 Open Office (Run A0 - Mod Weather Baseline.aps) Dry resultant temperature: 2-050 Open Office (Run A0 - Mod Weather Baseline-Winco.aps)

IES-VENatural Ventilation – Window Controls

IES-VENatural Ventilation – Window Controls

Thu Fri Sat

90

85

80

75

70

65

60

55

50

45

Te

mp

era

ture

(°F

)

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

Are

a (ft²)

Date: Thu 22/Jul to Fri 23/Jul

Air temperature: 2-050 Open Office (Proposed Building - 15 Final 0.154 Win.aps) Dry-bulb temperature: (Aspen_Co_TMY3-10-2014.epw)

Eqv area: External window 7 (Proposed Building - 15 Final 0.154 Win.aps)

Model ResultsThermal Comfort

PMV ASSUMPTIONS:

Morning Afternoon

Clo 1.0 Clo 0.57

Met 1.0 Met 1.0

Air Speed 19 FPM Air Speed 200 FPM

PMV -0.34 PMV -0.85

Morning Afternoon

Clo 1.0 Clo 0.57

Met 1.7 Met 1.7


PMV 0.72 PMV 0.04

Morning Afternoon

Clo 0.57 Clo 1.0

Met 1.0 Met 1.0


PMV -1.27 PMV 0.15

Morning Afternoon

Clo 0.57 Clo 1.00

Met 1.7 Met 1.7

Air Speed 19 FPM Air Speed 200 FPMPMV 0.26 PMV 0.77

People

Equipment (Installed)

Equipment (Operational)

Lighting (Installed)

Lighting (Operational)

Daylighting

Installed Heating

Heating Setpoint

Notes

Internal Load Assumptions:Room Floor Plan

Weather File

Schedule Description


0

10

20

30

40

50

60

70

80

90

100

50

55

60

65

70

75

80

85

90

95

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Rela

tive H

um

idit

y

Tem

peratu

re (⁰F

)

Hour

24 CONVENING 1-120 - convening exhaust fan

OSA Temp

Air Temp

MRT

RelativeHumidity

PMV = 0.14

PMV = 0.65PMV = -0.32

PMV = 0.73

PMV = -1.24

PMV = 0.27

PMV = -0.01

PMV = -0.71

PMV = 0.27

PMV = 0.14


h = 20 Btu/lb

h = 30 Btu/lb

h = 40 Btu/lb

h = 50 Btu/lb

0.0000

0.0020

0.0040

0.0060

0.0080

0.0100

0.0120

0.0140

0.0160

0.0180

0.0200

0.0220

0.0240

0.0260

0.0280

0.0300

30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Hu

mid

ity R

ati

o (

lbs

H2O

pe

r lb

s d

ry a

ir)

OperativeTemperature (⁰F)

Room Thermal Comfort PerformanceUpper Boundary(PMV = 0.5)

Lower Boundary(PMV = -0.5)

Room Hours

1. Upper boundary is based on the Elevated Air Speed Model, ASHRAE Standard 55-2013 Appendix G

1


h = 20 Btu/lb

h = 30 Btu/lb

h = 40 Btu/lb

h = 50 Btu/lb

0.0000

0.0020

0.0040

0.0060

0.0080

0.0100

0.0120

0.0140

0.0160

0.0180

0.0200

0.0220

0.0240

0.0260

0.0280

0.0300

30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Hu

mid

ity R

ati

o (lb

s H

2O

pe

r lb

s d

ry a

ir)




Room Hours


1



h = 20 Btu/lb

h = 30 Btu/lb

h = 40 Btu/lb

h = 50 Btu/lb

0.0000

0.0020

0.0040

0.0060

0.0080

0.0100

0.0120

0.0140

0.0160

0.0180

0.0200

0.0220

0.0240

0.0260

0.0280

0.0300

30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Hu

mid

ity R

ati

o (

lbs H

2O

per

lbs d

ry a

ir)




Room Hours - EC Room Hours - No EC


2. Lower boundary is based on implementation of the CBE Personal Comfort System (Heated, Ventilated Chair)

1 2


Model ResultsShortcomings/Workarounds - PCM

0%

10%

20%

30%

40%

50%

60%

Energy+ PCM Model PAE Equivalent MassWorkaround

Ene

rgy

Savi

ngs

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

Energy+ PCM Model PAE Equivalent MassWorkaround

Ene

rgy

Savi

ngs

Model ResultsShortcomings/Workarounds

• Shading/EC Control

• Input Verification

• Parametric Runs

Model ResultsEnergy

LIGHTS

SPACE HEATING

HYPERCHAIRS1.8%

CEILING FANS0.6%

VENTILATION FANS2.6%

PUMPS & AUXILIARY

1.5%

DOMESTICHOT WATER

ELEVATOR

DDC SYSTEM

KITCHEN EQUIPMENT

RESTROOM DRYERS &WASHLETS

1%

COPIERS & PRINTERS2%

CONFERENCE ROOMDISPLAYS

MONITORS1.3%

LAPTOPS2.5%

SERVERS & TELECOM

6%

5%

5%

3%

9%

14%

15%

29%

IF ALL LOW- AND MID RISE BUILDINGS IN THE US WERE CONSTRUCTED FROM RECLAIMED COLORADO BEETLE-KILL TIMBER…

…WE COULD MEET THE NEW BUILDING DEMAND FOR THE NEXT 17 YEARS.

IF ALL U.S. WORKERS REDUCED THEIR WATER BY THESE AMOUNTS…

…WE WOULD SAVE AN AMOUNT IN 2 MONTHS EQUIVALENT TO THE ANNUAL FLOW OF THE COLORADO RIVER.

IF EVERY COMMERCIAL BUILDING IN THE US INCREASED ITS ENERGY EFFICIENCY TO THIS LEVEL…

…WE WOULD SAVE ENOUGH ENERGY IN 1 MONTH TO POWER NEW YORK CITY FOR A YEAR.

Marc Brune, PE, LEED AP, Senior Associate, [email protected]

Ben Burnett, PE, [email protected]

John Breshears, Founder and President, Architectural [email protected]

mailto:[email protected]



Education

Energy and comfort modeling for the net zero rocky mountain institute headquarters