BuildingSimulation
BMEA
uildingodelingnergynalysis
What is BMEA?Models a building
Existing or proposed
• Shell and Core• Lighting• Equipment Load• Occupancy• Internal Mass
• Environmental Systems• Schedules• Climate• Utility Service
Shell and Core• Exterior walls Structure and finish• Windows Glass, frame, size• Doors Type and size• Roof Type, material, overhang• Shading Natural and structural• Insulation Type and R-value• Floors Floor covering and insulation• Ceiling Construction and insulation• Interior walls Construction and arrangement• Interior mass Furniture
Lighting
• Bulb
• Fixture
• PlacementRecessed, surface, or hanging
Open or enclosed
Equipment Load• Office Equipment• Infrastructure• Industrial Process
Load Breakdown
• Utility Total building load• Thermostat Loads in zones• Meter Loads in non-HVAC spaces
Environmental Systems• Built-up
• Package
• Split system• Air & water• Geothermal• Solar
• Process HVAC
• VFD Pumps and fans
• T-stat warm-up and setback
• Exhaust fans
• Zoning
• Domestic hot water
Schedules• Daily, weekly, and annual
• Weekends and holidays
• TypesOccupancyLightingEquipmentEnvironmental
Systems
Climate
• Model anywhere in the U.S.
• Seasonal
• Day and night
• 30-year average
Utility Service
• Electric and gas
• Anywhere in the U.S.
• Basic and demand charges
• Block and ratchet charges
• Rate analysis
What can BMEA do for me?
• Evaluate options
• Optimize strategies
• Compare costsSimple paybackLife cycleReturn-on-investment
• Evaluate energy usageRate reductionsRebatesTax credits
Reduce energy costs
Caveats
• Clearly defined objectives
• Cost-effective modifications
• Energy-usage figures are relative
• Cost vs. Value
Two-Story Office BuildingPortland, OR
Structure - 25,000 sq. ft.
6” concrete slab
Ext. Wall – 2 x 6 metal frame
Fiberboard sheathing
R-19 batt
Built-up roof
3” polyurethane R-18
Two-Story Office Building
Windows - ¼” Double-clear on North¼” Double-bronze all other
Doors - ¼” clear glass w/ 3” Al frame
Int. Wall - 2” x 4” metal frameDrywall
R-13 batt
Two-Story Office Building
Ceiling - Lay-in acoustic tile
No ceiling insulation
Floors- Carpet w/ fiber pad
12 foot floor-to-floor
9 foot floor-to-ceiling
Two-Story Office Building
Lighting - 2 x 4 concealed troffer
T8 ES fluorescent
High-efficiency magnetic ballast
Loads - 2 watt/sq. ft.
No exterior loads
Two-Story Office Building
Occupancy - 8 am – 5 pm
Mon – Fri
Major US holidays
90% while open
Two-Story Office Building
Environmental Systems
AHU Supply and return fansEconomizerConstant speed+1 hour open/closeChill water coil55F discharge air for cooling
Two-Story Office Building
VAV Core and perimeter zones74 / 72 Occ. – 82 / 64 Unocc.Plenum returnHot water heating coil95F discharge air for heat
Two-Story Office Building
Chiller - Electric recip. hermetic
Air-cooled condenser
44F supply water
Boiler - Natural gas
80% efficiency rating
180F discharge water
Two-Story Office Building
Domestic Hot Water Natural gas
88-gallon tank
135F discharge
Pumps Constant speed
Standard motor
Two-Story Office Building
Electricity PGE Schedule 32Small Non-Residential0.085/kW
Natural gas NW Natural Schedule 31Non-Residential0.95/Therm (100,000 Btu)
Running the SimulationBaseline
Electricity 146,650 kW $12,465
Natural gas 5,252 Therms
$4,935
Energy Total $17,400
Running the SimulationRaise Cooling Set Point
Raise cooling set point from 74F to 75F
Reduce annual electricity consumption
2250 kW annually
$190 per year
1.1% of annual energy cost
Running the SimulationReplacing the Boiler
Install 90% efficiency boiler
Reduce natural gas consumption
550 Therms annually
$525 per year
3.0% of annual energy cost
Oregon Business Energy Tax Credit
35% of project cost over five years
Running the Simulation Synergy
Raise the temperature and replace the boiler
2250kW $190 annually
737 Therms$695 annually
$885 in energy savings
5.1% of total energy bill
Building Modeling Energy Analysis
• Simulate an existing or proposed building
• Model a wide range of building elementsStructuralEnvironmental
• Flexible and adaptable
• Cost-effective analysis
Wrapping it Up