Building Simulation

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