through Early Stage Energy Modeling dl

This document has been abridged and does not include the full PowerPoint presented at Build Boston. Build Boston 09 Session B35 Achieving Sustainable Design through Early Stage Energy Modeling dl November 19, 2009 Presented by: Martine Dion AIA, Symmes Maini McKee Suzanne Robinson, PE LEED AP, Integrated Environmental Solutions

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Design Performance/Building Energy Simulation & Analysis How can we assess our designs relative to performance targets? Success will require innovative design strategies How can we implement innovative design strategies without our clients being guinea pigs?

Understanding your Targets SMMA

Integrated Design: considering the various building components together as a whole energy simulations daylighting analysis natural ventilation passive solar active solar thermal mass electrical mechanical lighting solar thermal daylighting yg g x x hybrid ventilation compliance CFD evacuation costs value

Common strategies for improving energy and environmental performance of buildings Use of atrium & courtyards Light shelving Embodied energy of materials Wind energy Ventilated facades Passive solar design principles Geo-thermal heat Adaptive comfort criteria Building orientation Maximization of daylight Chilled beams / ceilings Cogeneration Earth shelter roofs Displacement ventilation Biofuels High performance building technologies Photo-voltaics Night sky cooling Controls High efficiency boilers/chillers Solar water Solar heating water heating Beneficial shape and form Solar energy Advanced glazing and dinsulations Improved air tightness Use of thermal mass Underfloor heating/cooling The energy modeling tool a5cts as the calculator for true energy and environmental performance e.g.: First cost savings Energy consumption Running costs Carbon emissions Natural ventilation Optimum Night cooling Heat pumps Heat recovery configuration Clients value judgement filters strategies down to identify the optimum configuration e.g.: Natural ventilation Heat recovery Night cooling Heat pumps

ExternalClimate Data Building Geometry & Construction Thermal Properties HVAC Systems Internal Loads & Processes

Mass BIM 1 Early Stage Analysis: Massing 2 Schematic Design Occupancy and internal loads 3

Mass BIM 1 Comparative Analysis: Building Orientation Building Form High Building Envelope Options Glazing Types Percentage Glazing Glazing Location HVAC systems types 2 3

Mass BIM 1 What it shouldn t be used for 2 The 100% answer To replace analysis at the detailed design stage 3

Mass BIM 1 Benefits 2 Integrated team collaboration Helps communicate design to clients 3

SMMA MA CHPS Process through Project Phases Feasibility SD DD CD Bid CA Close out Green Charrette Early Workshop (preferred in programming) Intermediate Workshop Energy Modeling Daylight Modeling Life Cycle Cost Analysis Energy Water Design Process Building orientation Sun path study Prevailing winds Minimizing air conditioning Utility Incentives Acoustics MA CHPS criteria review Drawings Specifications MA CHPS Documentation MA CHPS Submittal

Early Stage Analysis Order 1. Building orientation 2. Building massing 3. Occupancy and internal loads 4. Glazing ratios 5. Passive Strategies - Daylighting - Natural Ventilation 6. Building Envelope 7. Mechanical Systems 8. Alternativeti Energy Sources

Case Studies How to use building performance analysis as a tool from different perspectives Design, assessment and verification Daylighting Energy modeling Natural ventilation

Daylight Metric and Targets LEED Credits Daylight Factor Energy Extract from CIBSE LG 10 Daylighting and window design The average daylight factor (DF) is a measure of the amount of skylight in a room. If a space has an average daylight factor of 5% or more will ensure that an interior i looks substantially bt ti daylit, except early in the morning, late in the afternoon or on exceptionally dull days. An average daylight factor below 2% generally makes a room look dull; electric lighting is likely to be in frequent use.

Scheme 1: Small Windows Scheme 2: Increased Glazing Scheme 3: Decreased Depth of Bldg Daylighting Assessment: So how can my massing models in Sketchup be used for daylighting assessment? LEED NC Credit 8.1 Daylighting: Does my options pass LEED NC Credit 8.1?

Scheme 1: Small Windows Scheme 2: Increased Glazing Scheme 3: Decreased Depth of Bldg Daylight Levels: ~30% Daylight Levels: ~71% Daylight Levels: ~77.5%

Scheme 1: Small Windows Scheme 2: Increased Glazing Scheme 3: Decreased Depth of Bldg LEED NC c8.1: Fail LEED NC c8.1: Fail LEED NC c8.1: Fail

Case Study: NE CHPS School IEQp16 Minimum Daylighting (prevent glare) No direct sunlight 4ft from window wall or light ratio cannot exceed 15:1 or max 5% daylight autonomy Skylights and roof monitors must comply (no direct light) Automatic daylight controls for lighting IEQc1.2 Daylighting in Classrooms 25%=1pt, 50% = 2pts, 75% = 3pts, 100% =4 pts. Daylight Distribution in Classrooms EGMS Maximum light ratio 8:1 (excluding 1 st 4ft) Minimum level 25fc or 2% daylight factor

Case Study: NE CHPS Sh School SMMA

Option 1: Approximately 50,000SF Option 2: Approximately 42,000SF More glazing Less depth on building Carbon/Energy Assessment: So how can my 2 design options be used for Carbon/Energy assessment?

Case Study: Removed Daylight andenergyanalysis, Natural Ventilation SMMA

Daylight Metric and Targets Et tf CIBSE LG 10 D li hti d i d d i Extract from CIBSE LG 10 Daylighting and window design The average daylight factor (DF) is a measure of the amount of skylight in a room. If a space has an average daylight factor of 5% or more will ensure that an interior looks substantially daylit, except early in the morning, late in the afternoon or on exceptionally dull days. An average daylight factor below 2% generally makes a room look dull; electric lighting is likely to be in frequent use.

Solar Gain Shading devices and local overhangs Can do schedule/sensor controlled operable shades, exterior louvers, etc. via window constructions, which then affect gain to spaces and surfaces as calculated previously by SunCast. Example: no shades hd vs. exterior shading vs. exterior shading and operable interior blinds controlled according to incident solar radiation. SMMA

Case Study: Partially Removed Daylight andenergyanalysis SMMA

<VE> Performance Analysis: ApacheSim (IES Consulting Service) Daylight Dimming Control Strategy SMMA Lighting Power (%) Lighting Power (%) Daylight Illuminance (ft c) Daylight Illuminance (ft c) No Dimming Step Dimming Continuous Dimming Description: The above curves demonstrate how the electrical lighting fixtures will be controlled under different daylight yg conditions. No Dimming Control: This is representative of the current store s lighting operation. It is assumed that all lights will be on between 6am and 10pm, and approx. 10% of lights will be on off hours (request information from Wegmans on actual off hour lighting operation) Continuous Dimming Control: This strategy is analogous to a dimmer knob it allows for continuous dimming of a fixture from its full output down to typically 10 15% output. New electronic lamp ballast technologies can allow for dimming down to 5% of a fixture s output. Step Dimming Control: This strategy allows for a 3 lamp fixture to turn off individual bulbs when target daylight levels are achieved. In this example, the first bulb will turn off when daylight can adequately provide 1/3 of the lighting, and the second bulb will turn off when daylight provides 2/3 of the lighting target. Typically the 3 rd lamp will always remain on regardless of daylight illuminance to prevent occupant distraction due to on/off operation Initial Conclusions: The following slides will demonstrate that significant lighting electricity savings can be achieved by utilizing a daylight dimming strategy. A proportional dimming control allows for significant additional savings to be achieved regardless of the sky conditions as it can respond to any quantity of daylight.

<VE> Performance Analysis: ApacheSim (IES Consulting Service) Potential Lighting Energy Savings Typical Spring Day (Clear Sky) Lighting Energy Consumption 1.6 No Dimming: Lighting on 100% Power all day 400 SMMA 1.4 350 1.2 Step Dimming Energy Savings 300 Ligh hting Energy (W W/sf) 1 0.8 0.6 Additional Savings from Proportional Dimming 250 200 150 Daylig ght Illuminance (ft c) 0.4 100 0.2 Daylight Reading at Sensor (ft candles) 50 0 0 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 23:57 Time Analysis: The total area under the solid line represents the lighting energy consumption with no dimming. On a clear spring day, we can see that the step dimming strategy performs well, switching off 1 bulb in the morning, and at mid day, 2 bulbs of the 3 lamp fixture can switch off for several hours. The proportional dimmer will provide significant additional savings throughout the day time. Note that at midday, the proportional dimming can reduce the lighting energy down to 15% or less. The step dimmer can only reduce the lighting energy to 33%.

<VE> Performance Analysis: ApacheSim (IES Consulting Service) Potential Lighting Energy Savings Typical Spring Day (Overcast Sky) Lighting Energy Consumption 1.6 No Dimming: Lighting on 100% Power all day 400 SMMA 1.4 350 1.2 Step Dimming Energy Savings 300 Ligh hting Energy (W W/sf) 1 0.8 0.6 Additional Savings from Proportional Dimming 250 200 150 Daylig ght Illuminance (ft c) 0.4 100 0.2 Daylight Reading at Sensor 50 0 0 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 23:57 Time Analysis: On this overcast spring day, when utilizing a step dimming strategy, the daylight sensor will achieve an adequate reading to switch off one bulb for only a short period of the day. The proportional dimmer will provide significant additional savings even with the lower daylight conditions.

<VE> Performance Analysis: ApacheSim (IES Consulting Service) Potential Lighting Energy Savings Typical Summer Day Lighting Energy Consumption 1.6 No Dimming: Lighting on 100% Power all day 400 SMMA 1.4 350 1.2 Step Dimming i Energy Savings 300 Ligh hting Energy (W W/sf) 1 0.8 0.6 Additional Savings from Proportional Dimming 250 200 150 Daylig ght Illuminance (ft c) 0.4 Daylight Reading at Sensor (foot candles) 100 0.2 50 0 0 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 23:57 Time Analysis: On a summer day, the step dimmer performs well and can reduce to 1/3 power for a large portion of the day. The additional savings achieved by the proportional dimmer occur early and late in the day, at daylight conditions between the steps, and for much of the day when daylight conditions allow for full dimming to occur.

<VE> Performance Analysis: ApacheSim (IES Consulting Service) Potential Lighting Energy Savings (TypicalWinter Day) Lighting Energy Consumption 1.6 No Dimming: Lighting on 100% Power all day 400 SMMA 1.4 350 1.2 Step Dimming Energy Savings 300 Ligh hting Energy (W W/sf) 1 0.8 0.6 Additional Savings from Proportional Dimming 250 200 150 Daylig ght Illuminance (ft c) 0.4 Daylight Reading at Sensor (foot candles) 100 0.2 50 0 0 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 23:57 Time Analysis: On a more typical winter day, the step dimmer can provide benefit for portions of the day. Again, we can see that the proportional dimming strategy is very effective with intermediate quantities of daylight.

Energy Metric and Targets Comparative vs. Predictive i Early stage Baseline = industry standard Late stage Baseline = ASHRAE 90.1 [LEED]

Case Study: Removed Building Envelopeand EnergyAnalysis SMMA

Natural Ventilation Metric and Targets Currently there are no established parameters set for indoor air thermal comfort in buildings utilizing natural ventilation. A building s comfort range is based on: regional outdoor ambient temperature humidity occupant activity individual psychological perception of comfort; thus making a temperature range difficult to pinpoint. Two recent studies fromthe NationalInstitute of Science and Technology and the Center for Environmental Design Research at the University of California Berkeley suggest a reasonable indoor comfort zone between drybulbtemperatures of20 20 26 C (68 79 F) and limiting dew point temperature of 17 C (63 F)or ambient outdoor temperatures of 23 C (73 F) and below.

Natural & Mixed-mode Ventilation Ventilation driven by pressure differentials Secondary air outlet Primary ventilation air intake duct to underfloor (UFAD) plenum Wind driven (U ) pe u Stack effect +/ HVAC pressure BAS control of facade ventilation openings Mixed mode operation Thermal stratification UFAD and thermal displacement ventilation User controlled operable vent Primary air outlet to stack vent in building core

Natural Ventilation Metric and Targets The other component of natural ventilation is the direction and magnitude of local wind speeds. Naturalventilationis inadequate for climate areasoutside of a Natural ventilation is inadequate for climate areas outside of a range of 5 15 C (41 59 F) with average wind speeds lower than 1 m/s or 2.24mph.

Wind Studies SMMA

Case Study: Removed Daylight andenergyanalysis, Natural Ventilation SMMA

Climate classification SMMA

Shoulder Months Monthly Average Dry Bulb F) (deg. 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Months of the year Average High Average Low Average Potential opportunities for natural ventilation shown in blue.

Shoulder Days Operating hours: 6 am to 11 pm Month AmbientAirTemp Air AmbientAirTemp20 C/68 F Air AmbientDewPointTemp63 FF 23 C/73 F (hrs) (hrs) (hrs) January 525 508 527 February 476 470 476 March 460 407 491 April 473 378 485 May 182 94 281 June 60 28 141 July 32 0 17 August 65 24 61 September 160 67 149 October 378 302 482 November 467 400 448 December 527 527 527 ANNUAL 3805 3205 4085

Site wind speed SMMA Site wind speed 40 35 30 25 Frequency (%) 20 15 Wind speed (mph) 10 5 0 < 0 0 to 5 5 to 10 10 to 15 15 to 20 20 to 25 25 to 30 30 to 35 > 35 wind speed (mph)

Monthly Wind Roses SMMA JAN. FEB. MAR. Annual mean wind speed 8.8 mph Annual mean direction 178 E of N APR. MAY JUN. JUL. AUG. SEP. OCT. NOV. DEC.

Passive/Hybrid Ventilation Strategies For more information on this subject check out IES s IQ2 Greenbrief Located in our whitepapers section of the website: Located in our whitepapers section of the website: www.iesve.com/content/mediaassets/pdf/iq2.pdf

Breaking design process barriers Further promotes integrated t ddesign Architects /Engineers Engineers/Engineers Owner involvement Don t be afraid to talk to your engineers Moving forward the necessary shift in mindset for right sizing equipment. Focused analysis It s never too early Start before building form is established

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