1

Energy and HVAC System Implications of Daylighting Design

Tom Marseille, P.E.

Managing Principal

2

• Our primary objectives are (or should be):

– Delivering occupant comfort

– Helping provide a healthy environment

– Providing ever more energy efficient

buildings (becoming a mandate)

– Providing maintainable/reliable systems

– Hold down mechanical first cost(!)

What do Mechanical Engineers Care About?

3

• Our primary objectives are (or should be):

– Delivering occupant comfort

– Helping provide a healthy environment

– Providing ever more energy efficient buildings

– Providing maintainable/reliable systems

– Hold down mechanical first cost(!)

What do Mechanical Engineers Care About?

4

Comfort First

5

• Thermal comfort is affected by:

– air temperature (what your thermostat says)

– mean radiant temperature - The average temperature of all the surfaces to which a person is exposed, exchanging infrared radiation.

• Radiating surfaces (e.g., hot or cold windows) can reduce occupant comfort

• How occupants interact with glazing impacts comfort

Comfort First

6

Blinds

95°F

Air temperature 73°F

Room objects 73°F

Resultant temperature 75°F

Mean radiant temperature 77°F

Small angle

Radiant temperature influence: far from window

Sunlight

Comfort

7

Blinds

95°F

Resultant temperature 79°F

Mean radiant temperature 84°F

Large angle

Air temperature 73°F

Room objects 73°F

Radiant temperature influence: close to window

Sunlight

Comfort

8

Air temperature 73°F

Room objects 73°F

Resultant temperature 82°F

Mean radiant temperature 90°F

Radiant temperature: sunshine through window

Sunlight

Comfort

9

Sunlight

Air temperature 73°F

Room objects 73°F

Resultant temperature 73°F

Mean radiant temperature 73°F

Radiant temperature: externally shaded window

Shade

Comfort

10

Perceived Temperature vs. Air Temperature

00:00 06:00 12:00 18:00 00:00

90

85

80

75

70

65

60

55

Te

mp

era

ture

(°F

)

Date: Mon 02/Aug

Dry resultant temperature: Level 5 West Office (odot_west_conf1.aps)

Mean radiant temperature: Level 5 West Office (odot_west_conf1.aps)

Air temperature: Level 5 West Office (odot_west_conf1.aps)

11

00:00 06:00 12:00 18:00 00:00

90

85

80

75

70

65

60

55

Te

mp

era

ture

(°F

)

Date: Mon 02/Aug

Dry resultant temperature: Level 5 West Office (odot_west_off1.aps)

Mean radiant temperature: Level 5 West Office (odot_west_off1.aps)

Air temperature: Level 5 West Office (odot_west_off1.aps)

Perceived Temperature vs. Air Temperature

12

• South exposure

– moderate solar load in winter for heating

– low solar load in summer if shaded

• East and West exposure

– high morning and evening solar load

– shading less effective

• Not all building exposures need the same treatment

Different solar loads by exposure

Glazing – just another load to be managed?

13

Treatment of different exposures

• Façades should be treated according to which direction they face

• For example, for cold winters, hot summers in northern hemisphere:

– reduced windows on north side

– windows with overhangs/shading on south side

– deciduous shading on west end to reduce late afternoon overheating in summer

Glazing – just another load to be managed?

14

North East

Architect's View of the Sun - Radiation

ANNUAL SUMMARY: Btu/SF Hr.

Hour DEC JAN-NOV FEB-OCT MAR-SEP APR-AUG MAY-JUL JUNE

113 °AZI

0 0 0 0 0 0 0 0

1 0 0 0 0 0 0 0

2 0 0 0 0 0 0 0

3 0 0 0 0 0 0 0

4 0 0 0 0 0 0 0

5 0 0 0 0 0 0 0.1

6 0 0 0 0 68.7 121.8 134.2

7 0 0.0 72.7 149.5 183.2 194.9 195.7

8 76.7 99.0 145.4 179.4 194.9 199.8 199.0

9 76.4 89.5 120.7 148.9 163.7 169.8 170.3

10 37.7 45.3 65.5 87.6 106.0 116.6 119.6

11 20.5 22.3 26.3 34.4 49.4 60.9 65.3

12 21.4 23.2 27.2 31.7 36.2 39.3 40.5

13 20.5 22.3 26.3 30.7 35.3 38.5 39.7

14 17.8 19.6 23.6 28.0 32.7 36.0 37.3

15 13.3 15.1 19.1 23.6 28.5 32.0 33.4

16 6.4 8.4 12.8 17.6 22.7 26.4 28.0

17 0 0.0 3.7 9.4 15.1 19.3 21.0

18 0 0 0 0 4.1 9.3 11.4

19 0 0 0 0 0 0 0.0

20 0 0 0 0 0 0 0

21 0 0 0 0 0 0 0

22 0 0 0 0 0 0 0

23 0 0 0 0 0 0 0

24 0 0 0 0 0 0 0

TOTAL 291 345 543 741 940 1065 1095

DEC

FEB-OCT

APR-AUG

JUNE

0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

180.0

200.0

TIME

34 °LAT113 °AZI

Glazing

Transmitted Radiation

15

00:00 06:00 12:00 18:00 00:00

35000

30000

25000

20000

15000

10000

5000

0

Lo

ad

(B

tu/h

)

Date: Thu 08/Jul

Cooling plant sensible load: Level 15 West (egww_overhang(d)towindow(h)_1to2.aps)

Cooling plant sensible load: Level 15 West (egww_overhang(d)towindow(h)_2to1.aps)

Cooling plant sensible load: Level 15 West (egww_overhang(d)towindow(h)_1to1.aps)

Cooling plant sensible load: Level 15 West (egww_noshade.aps)

Cooling plant sensible load: Level 15 West (egww_fins_surr.aps)

No Shade

1:1 ratio horizontal overhang

35 btu/sq ft

25 btu/sq ft

Vegetated fins

Shading options/relative cooling load

16

00:00 06:00 12:00 18:00 00:00

40000

35000

30000

25000

20000

15000

10000

5000

0

Lo

ad

(B

tu/h

)

Date: Tue 05/Oct

Cooling plant sensible load: Level 15 South (egww_noshade_gp40.aps)

Cooling plant sensible load: Level 15 South (egww_noshade_gp30.aps)

Cooling plant sensible load: Level 15 South (egww_noshade.aps)

33 btu/sq ft

Glazing Percentage – / south / relative cooling load

40 btu/sq ft

45 btu/sq ft

17

Building Codes Are Not Fans Of Excessive Glazing

18

Manufacturer ProductVisi Trans

%

Shading

Coefficient U-Value

Standard Clear IG 79 0.81 0.52

PPG Solarban 60 69 0.44 0.30

Interpane Super E 69 0.46 0.29

Cardinal Low E2 171 70 0.46 0.30

Viracon VE 1-2M 70 0.44 0.29

Viracon VE 1-85 76 0.64 0.31

Heat Mirror HMTC88 63 0.55 0.30

Heat Mirror HMSC75 61 0.41 0.34

Selected Glazing Performances

Glazing

PPG Solarban 70XL 64 0.32 0.28

19

Benefits of Solar Load Reduction

• Improved comfort for occupants at perimeter

• Reduced HVAC equipment sizes

• Reduced energy usage

20

Energy

Source: Energy Information Administration Statistics (Architecture 2030)

INDUSTRY25%

TRANSPORTATION27%

BUILDINGS48%

21

Source: Arctic Climate Impact Assessment

Why Do We Care?

22

23

www.architecture2030.org

BUILDINGBUILDINGBUILDINGBUILDINGSTOCKIN BILLION SF

24

WHYWHYWHYWHYBUILDING?BUILDING?

25

WHYWHYWHYWHYBUILDING?BUILDING?

26

WHYWHYWHYWHYBUILDING?BUILDING?

27

WHYWHYWHYWHYBUILDING?BUILDING?

28

WHYWHYWHYWHYBUILDING?BUILDING?

29

WHYWHYWHYWHYBUILDING?BUILDING?

30

ENERGY REGULATION – INDICATOR AND DRIVER

ASHRAE Standards• 90.1 2010 requires 30% more efficiency than 90.1 2004

• ASHRAE 189.1 – 30% more efficient than current 90.1

• ASHRAE goal – market viable Net Zero Energy (NZE) buildings by 2030

AIA• 2030 challenge – achieve carbon neutral (NZE) buildings by 2030

USGBC Cascadia Chapter•“Living Building Challenge” - NZE buildings today!

State of Washington• Legislation SB 5854 – incremental reductions, to 70% reduction by 2031

31

The Energy “Pie” Chart – Office Buildings

Office Building

LIGHTS

26%

MISC EQUIP

10%

SPACE HEATING

46%

HEAT REJECT

0%

PUMPS & AUX

5%

VENT FANS

5%

DOMEST HOT WTR

3%

SPACE COOLING

5%

32

Residential Lighting Energy UseLighting

Room Type

Operation (hr/

day/ room)

Typical Townhouse

Lighting

Lighting Power

(assuming 15

W CFD = 60 W

Incandescent)

Number of room

type in one bed

unit

Number of

Room type

in a two

bed unit

Number of

Room type

in a three

bed unit

Bathroom 1.8

1 light over sink, one

in bath/shower 45 1 2 2

Powder Room 1.8 2 lights 30 1 1 1

Bedroom 1.1

2 light central fixture,

assume one light on

bedstand 30 1 2 3

Closet 1.1 No lighting 0 0 0 0

Dining Room 2.5 3 overhead lights 45 1 1 1

Garage 1.5 2 4' flourecsent 60 0 0 1

Hall 1.5 7 lights in a 2 bed unit 15 5 7 8

Kitchen 3 Use 8 lights 120 1 1 1

Living Room 2.5

5 overhead lights 1

wall wash 90 1 1 1

Office 1.7

2 light central fixture,

assume one light on

desk 45 1 1 1

Outdoor 2.1 3 lights 45 1 1 1

Utility Room 2 2 light central fixture 30 1 1 1

Lighting Density (W/SF) 0.56 0.41 0.36

Daily lighting load (W-hr) 1009.5 1099.5 1134

Annual lighting load (kWh) 368 401 414

Operation Hours from Navigant Consulting 2002 sample of 161 NW homes

Annual Exterior Lighting Load (kWh) 34.5 34.5 67.3

33

The Energy “Pie” Chart - ResidentialTypical 2 Bedroom Townhouse - Seattle

Space Heating

Misc Equip (Plug)

LightsDomestic Hot Water

Vent Fans

Mech Aux

Assuming efficient CF lighting, it can be a small piece of the pie

34

Component Interaction – Office Building

35

Base Building: Office Building….Four Story….Floor-to-floor height = (12 ft)

Base Building (10’ Windows)

Window Height = 3 m (10 ft)

Peak Cooling Load = 76 Tons

Annual Energy Cost = 100 units

Window Height = 1.5 m (5 ft)

Peak Cooling Load = 61 TonsAnnual Energy Cost = 81 units

5’ Windows

Window Height = 2.4 m (7 ft)

With external overhangs (5 ft)

Peak Cooling Load = 51 TonsAnnual Energy Cost = 80 units

7’ Windows & overhangs

Impact of Window Height

Energy

36

Impacts of Glass Performance

Window Height = 3.0 m (10 ft)

U=0.31 SC=.37 VLT=55

Peak Cooling Load = 72 Tons

Annual Energy Cost = $ 91 units

Window Height = 1.5 m (5 ft)

U=0.46 SC=0.42 VLT=60

Peak Cooling Load = 61 TonsAnnual Energy Cost = $ 81 units

Window Height = 2.4 m (7 ft)

With external overhangs (5 ft)

U=0.35 SC=.70 VLT=74

Peak Cooling Load = 60 TonsAnnual Energy Cost = $ 84 units

Base BuildingWindow Height = 3.0 m (10 ft)

Floor-to-floor height = 3.7 m (12 ft)

U=0.46 SC=0.42 VLT=60

Peak Cooling Load = 76 TonsAnnual Energy Cost = $ 100 units

Low-E Glass

Standard Glass

High Performance Glass

Energy

37

Window Height = 3.0 m (10 ft)

U=0.31 SC=.37 VLT=55

Peak Cooling Load = 66 Tons (72 Tons)Annual Energy Cost = 88 units

Window Height = 1.5 m (5 ft)

U=0.46 SC=0.42 VLT=60

Peak Cooling Load = 54 Tons (61 Tons)Annual Energy Cost = 80 units

Window Height = 2.4 m (7 ft)

With external overhangs (5 ft)

U=0.35 SC=.70 VLT=74

Peak Cooling Load = 53 Tons (60 Tons)Annual Energy Cost = 83 units

Base BuildingWindow Height = 3.0m (10 ft)

Floor-to-floor height = 3.7m (12 ft)

Daylighting Control: Dimming

Illuminance Level: 37 fc

Peak Cooling Load:“with daylighting (without daylighting)”

7’ Windows

5’ Windows

10’ Windows

Impacts of Daylighting

Energy

38

ITERATIVE PROCESS�Thermal Analysis to determine

shading needed as well as glass percentage impact

�Shading Analysis to determine glare issue (direct solar)�Daylighting Analysis to determine

glare (contrast ratio)�Daylighting Analysis to determine

lighting usage reductions�Lighting schedules - modeling input�Energy Analysis - lighting energy

and other end use savings

glare

daylighting

lighting Ventilation

cooling

shading

Daylighting – incorporation into sustainable design process

39

Terry Avenue Case Study

40

This plan places each worker within 20 feet of an operable window.

General Motors Building, Detroit, 1921, Albert Kahn, Inc., Architects

General Motors Building, Detroit Terminal Sales Building, Seattle

NATURAL VENTILATION AND DAYLIGHTING

This is not new!!!

41

NATURAL VENTILATION STRATEGY

Terry Avenue Case Study

• Operable windows and automated dampers in occupied spaces

• Building form chosen to facilitate cross ventilation and day-lighting

• Narrow floor plate (approximately 35’ deep)

42

MECHANICAL DESIGN

• Operable windows in all spaces

• Trickle vents for minimum ventilation

• Automated dampers above windows

• CO2 sensors

• Night purge control strategy

• Occupant education about NV

• High efficiency hydronic heating

• Convection heaters at perimeter

• Minimal ductwork

• No mechanical cooling

Terry Avenue Case Study

43

The building was analyzed

at different times of day

throughout the year. This

helped shading:

• Type

• Location

• Orientation

SOLAR SHADING ANALYSIS

Terry Avenue Case Study

44

SOLAR SHADING SELECTION

• High performance glazing

• External adjustable aluminum blinds in

courtyard and portions of exterior

• Steel and glass sunshades

Terry Avenue Case Study

45

DAYLIGHTING

• Balance benefits of day-lighting

with solar gain mitigation

• High performance thermal

envelope

• Windows/louvers sizes and

locations

Terry Avenue Case Study

46

ANALYSIS

Build Model:

• Walls

• Climate data

• 3-D geometry

• Windows/openings

• Shading

• Internal loads

• Aperture schedules

• Occupant schedules

Thermal Analysis

47

Basel

ine

NE C

onf

NE C

onf

Basel

ine

Cof

fee

Cof

fee

Basel

ine

Acc

t.

Acct.

167 162 155155 158

155

2930 36 37 43 44

77 8

88

8

0

20

40

60

80

100

120

140

160

180

Run iterations until satisfied with the results of the model

Finesse the Model:

• Fine tune the loads

• Substitute glazing

• Increase/decrease amount of

glazing

• Substitute wall constructions

• New shading options

• Increase/decrease amount of

operable windows

ANALYSIS

Thermal Analysis

48

1042%

938.5%

835%

731.5%

628%

524.5%

421%

317.5%

214%

110.5%

LEED

POINTS

TOTAL

ENERGY

SAVINGS

Energy Savings per System

5 PTS!

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

Vent Fans Space

Cooling

Pumps &

Aux

Lights Space

Heating

Domestic

HW

Misc Equip

Perc

en

t S

avin

gs f

rom

Baselin

e

Terry Avenue Case Study

49

Terry Avenue - Measured Performance

• Artificial LPD averages 0.38 W/SF (Code = 1.0)

• Energy use much lower than LEED Model

Energy Consumption [kBtu/yr]

End Use Total Building

Electricity

Office Space 389,876 763,118

Common Areas2

40,208 78,701

Elevators 19,718 38,594

Natural Gas

Boilers3

379,095 975,712

Total Energy [kBtu/yr] 828,896 1,856,125

Total Energy [kBtu/sf-yr] 40.1 45.9

Total Energy Cost [$/sf-yr] 0.57 0.64

Notes:

1. Weber + Thompson Architects occupy levels 2 and 3 (i.e., 20,700 sf).

2. Common areas does not include parking garage or exterior lighting.

4. Energy cost based on the following utility rates from bills:

Electric Rate [$/kWh]: $0.0551

Natural Gas Rage [$/Therm]: $1.197

Webber + Thompson

Space1

3. Weber +Thompson portion of natural gas consumption based on ratio of

heat load for occupied space to total heat load of building.

53% better than the average office according to CBECS data

60% - 70% better than average office according to BOMA data

50

Case Study – Edith Green Wendell Wyatt Federal Office Building

Studies done for different options to determine optimum solution for

�Glazing percentage�Glazing properties�Shading Strategy

�Daylighting Strategy

51

Thermal AnalysisSouth – shading options / relative cooling load

00:00 06:00 12:00 18:00 00:00

40000

35000

30000

25000

20000

15000

10000

5000

0

Lo

ad

(B

tu/h

)

Date: Tue 05/Oct

Cooling plant sensible load: Level 15 South (egww_overhang(d)towindow(h)_1to2.aps)

Cooling plant sensible load: Level 15 South (egww_overhang(d)towindow(h)_2to1.aps)

Cooling plant sensible load: Level 15 South (egww_overhang(d)towindow(h)_1to1.aps)

Cooling plant sensible load: Level 15 South (egww_noshade.aps)

Cooling plant sensible load: Level 15 South (egww_intblinds.aps)

No Shade

1:1 ratio horizontal overhang

35 btu/sq ft

25 btu/sq ft

�Thermal Analysis to determine shading needed as well as glass percentage impact

52

00:00 06:00 12:00 18:00 00:00

40000

35000

30000

25000

20000

15000

10000

5000

0

Lo

ad

(B

tu/h

)

Date: Mon 16/Aug

Cooling plant sensible load: Level 15 East (egww_overhang(d)towindow(h)_1to2.aps)

Cooling plant sensible load: Level 15 East (egww_overhang(d)towindow(h)_2to1.aps)

Cooling plant sensible load: Level 15 East (egww_overhang(d)towindow(h)_1to1.aps)

Cooling plant sensible load: Level 15 East (egww_noshade.aps)

Cooling plant sensible load: Level 15 East (egww_intblinds.aps)

No Shade

1:1 ratio horizontal overhang

35 btu/sq ft

25 btu/sq ft

East– shading options / relative cooling load

Thermal Analysis

53

00:00 06:00 12:00 18:00 00:00

16000

14000

12000

10000

8000

6000

4000

2000

0

Lo

ad

(B

tu/h

)

Date: Wed 16/Jun

Cooling plant sensible load: Level 15 North (egww_overhang(d)towindow(h)_1to2.aps)

Cooling plant sensible load: Level 15 North (egww_overhang(d)towindow(h)_2to1.aps)

Cooling plant sensible load: Level 15 North (egww_overhang(d)towindow(h)_1to1.aps)

Cooling plant sensible load: Level 15 North (egww_noshade.aps)

Cooling plant sensible load: Level 15 North (egww_intblinds.aps)

No Shade20 btu/sq ft

North – shading options / relative cooling load

Thermal Analysis

54

West – shading options / relative cooling load

00:00 06:00 12:00 18:00 00:00

35000

30000

25000

20000

15000

10000

5000

0

Lo

ad

(B

tu/h

)

Date: Thu 08/Jul

Cooling plant sensible load: Level 15 West (egww_overhang(d)towindow(h)_1to2.aps)

Cooling plant sensible load: Level 15 West (egww_overhang(d)towindow(h)_2to1.aps)

Cooling plant sensible load: Level 15 West (egww_overhang(d)towindow(h)_1to1.aps)

Cooling plant sensible load: Level 15 West (egww_noshade.aps)

Cooling plant sensible load: Level 15 West (egww_fins_surr.aps)

No Shade

1:1 ratio horizontal overhang

35 btu/sq ft

25 btu/sq ft

Vegetated fins

Thermal Analysis

55

00:00 06:00 12:00 18:00 00:00

40000

35000

30000

25000

20000

15000

10000

5000

0

Lo

ad

(B

tu/h

)

Date: Tue 05/Oct

Cooling plant sensible load: Level 15 South (egww_noshade_gp40.aps)

Cooling plant sensible load: Level 15 South (egww_noshade_gp30.aps)

Cooling plant sensible load: Level 15 South (egww_noshade.aps)

33 btu/sq ft

Glazing Percentage – no shade / south / relative cooling load

40 btu/sq ft

45 btu/sq ft

Thermal Analysis

56

Solar Altitudes

Month 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00

Jan - - - 1 9 16 21 23 23 19 14 7 - - -

Feb - - - 6 15 23 28 31 31 27 22 14 5 - -

Mar - - 5 15 24 33 38 41 41 37 30 21 12 1 -

Apr - 5 15 26 36 44 51 54 52 47 39 29 19 9 -

May 2 12 23 33 43 53 60 63 61 54 45 35 25 14 4

Jun 5 15 25 35 46 55 64 68 66 59 49 39 29 18 8

Jul 3 13 23 33 44 53 61 66 64 58 49 39 28 18 8

Aug - 7 18 28 38 47 55 58 57 51 43 33 23 12 2

Sep - 1 11 21 31 39 44 47 45 40 32 23 13 2 -

Oct - - 4 14 22 29 33 35 33 28 21 12 3 - -

Nov - - - 6 14 20 24 25 24 19 13 5 - - -

Dec - - - 1 9 15 19 21 20 16 11 3 - - -

Required Shading

east

south

altitude > 45 red

East

South

Diagonal shading – south and east Diagonal shading

Shading Analysis - Quantitative

Times when shading required for Radiant system

�Shading Analysis to determine glare issue (direct solar)

57

Shading Analysis – Qualitative View

58

�Impact of surrounding buildings

Daylighting Analysis�Daylighting Analysis to determine glare issue (contrast ratio)

59

Daylighting Analysis�Daylighting Analysis to determine lighting usage – lightign schedules for energy analysis input

Artificial sky at ESBL Univ of Oregon and physical model (scaled) used for daylighting studies

60

Lighting Energy

0

500

1000

1500

2000

2500

3000

3500

4000

4500

no daylighting

savings

w ith daylight

sensors

w ith adj ltg sch

MB

TU

Energy Analysis�Energy Analysis lighting energy and other end use savings

Comparison of results from 2 methods of determining lighting energy savings due to daylighting

�lighting sch input from external daylight study (physical model)�eQUEST daylight sensors used

Typical Lighting schedule for each month, each orientation (workday, Saturday and Sunday)

Following methods may be used to model savings due to daylighting

1. Determine lighting schedule to model daylighting impact

� Physical scaled model� Daylighting Analysis tool

2. Model within energy analysis tool

Office | Lighting

Weekdays

0%

20%40%

60%80%

100%

12

AM

3 A

M

6 A

M

9 A

M

12

PM

3 P

M

6 P

M

9 P

M

Office | Lighting

South (Apr/Aug)

Weekdays

0%

50%

100%

12

AM

3 A

M

6 A

M

9 A

M

12

PM

3 P

M

6 P

M

9 P

M

Example schedule

61

Skylight (no shade)Sunny Sky Studies

Sept 1200 (sunny sky)

Daylighting Analysis – Software Approach

62

Daylighting for Classrooms

0

10

20

30

40

50

60

70

80

90

2.25 6.75 11.25 15.75 20.25 24.75 29.25 33.75

distance from window

footc

andle

s

Iteration 1 - option 2 withnorth roof overhangremoved

Iteration 2 - interior lightshelf + iteration 1

Iteration 3 - higherclearstory + iteration 1

Iteration 4 - interior lightshelf + iteration 3

Iteration 5 - 1 foot higherthan iteration 3

Iteration 6 - interiorlightshelf + iteration 5

Iteration 7- 1 foot higherthan iteration 5

Iteration 8 - interiorlightshelf + iteration 7

Iteration 9- north monitor+ iteration 3

Daylighting Analysis Tools

�Quantitative

63

SHADINGUW – EDUCATIONAL OUTREACH

64

� HVAC System

� roof insulation

� wall insulation

� glazing

� exterior shades

� daylight Sensors

� CO2 sensors

Energy Conservation MeasuresHANFORD REACH MUSEUM AND VISITOR CENTER

65

� HVAC system

� roof insulation

� wall insulation

� glazing

� exterior shades

� daylight sensors

10% savings

overall (30%

savings in lighting

energy, 12%

savings in cooling

energy)

� CO2 sensors

Energy Conservation MeasuresHANFORD REACH MUSEUM AND VISITOR CENTER

20%

savin

gs

66

Summary of Energy implications of Daylighting

Electrical demand savings:

� Reduced lighting load

� Reduction in HVAC load (chiller plant power)

� Electricity reduction during peak load

� Potential increase in heating load of perimeterspaces

Lighting and its associated cooling energy can constitute up to 30% of a commercial office building's total energy use.

67

Energy implications or over all effect of daylighting

Daylighting Economics

� A well-designed daylighting application can reduce

energy costs 10 – 30%.

� Lighting energy can be reduced up to 70 percent

during peak natural light periods.

68

Questions?

Tom.marseille@stantec.com

Thank you!