4. TERMINOLOGY
R-value (or “U-factor”) – thermal resistance
SHGC or solar heat gain coefficient – heat from the sun, typically thru windows or skylights
Schedule – when something is on or off, also used when the building is occupied. Usually
used as a percentage of fully “on” or occupied.
Building Mass – “thermal inertia” or the ability (rate) of a building to absorb and retain heat.
The higher the building mass, the more heat energy is retained in the building over time.
Plug or Process Loads – Typically loads that are plugged in. An example would be a desk
lamp or computer.
HVAC – Heating, Ventilation & Air Conditioning
Economizer – typically refers to scheduling an HVAC system to blow air without the
heaters and chillers (refrigerant) being used/on.
9. COMMON MISUNDERSTANDINGS
Energy modeling isn’t for me. Isn’t a big firm, big
project need?
Energy modeling is too detailed. Can’t we get what
we need to know without it?
Will energy modeling detract from my other design
goals?
I’m worried that energy considerations and integrated
design teams will limit design decisions.
Energy modeling takes time and resources. Can our
firm afford to do it?
11. BASIC METHODOLOGY
1. Providing Inputs to the Energy Modeler
2. Calculate the baseline or proposed
building energy use
3. Analyze outputs to determine the most
cost effective strategy or bundle of
strategies
4. Modify inputs and provide to Energy
Modeler
5. Repeat, repeat, repeat, until the desired
outcome is met – design is an iterative
process
12. WHO IS INVOLVED???
Energy Modeler
Architect
MEP Engineer (& Lighting Consultant, if separate)
Builder/Contractor
Owner/Developer
Facilities or Building Manager
Occupants
KEY STAKEHOLDERS & COLLABORATORS
18. START EARLY!!!
Over 30%
of the potential passive
design energy
reduction stratagies are
lost after the
Conceptual Design
Phase.
19. AREAS TO EVALUATE
Massing/Orientation
Daylighting (passive & active)
Natural Ventilation (if applicable)
Envelope (Roof, Walls, Slab, Windows, Doors,
Exposed Assemblies, etc.)
Lighting Power (Indoor/Outdoor)
HVAC (equipment efficiencies, controls, sizing)
Indoor Water Use & Domestic Hot Water Heating
(efficiencies & controls)
Plug Load Reduction & Controls
Renewable Energy Technologies (Wind, Solar,
Solar Thermal
Operational Schedules/Temperature Setpoints
Tenant Engagement Plan/Education
ENERGY CONSERVATION MEASURES (ECMs)
PASSIVE STRATAGIES
OPERATIONAL
STRATAGIES
ACTIVE STRATAGIES
20. BENEFITS OF ENERGY MODELING
Enabling Design: Energy modeling
enables design teams to focus their
time effectively.
New Expertise: The additional
technical expertise associated with
energy modeling makes the
involvement of the architect more
valuable throughout the project.
Increased Referrals: Can result in
higher client and project team
satisfaction—and future referrals.
FOR THE ARCHITECT
21. BENEFITS OF ENERGY MODELING
Reduced First Cost through Right-
Sizing
Reduced Operating Costs
Reduced Maintenance Costs
Greater Predictability of Operating and
Maintenance Costs
Guidance for the Structuring of Real
Estate Agreements
Incentives
Increased Asset Value
FOR THE OWNER
22. BENEFITS OF ENERGY MODELING
Enhanced Comfort for Occupants
Higher Occupant Satisfaction:
Assessment of thermal comfort,
daylight penetration, glare-control, etc.,
alongside energy performance can
lead to a space that is more
productive, vibrant, and satisfying to
the occupant.
Improved Environmental
Performance
FOR THE BUILDING OCCUPANTS
28. AIA 2030 BASELINE
A standard reference building (based on usage type) defined by the
National Median EUI. See…..
ENERGY STAR Target Finder - This data is based on regional
medians and will typically be more accurate than national averages.
National Average – typically for use types not available in ENERGY
STAR Target Finder
Create Your Own – requires 2000 IECC baseline inputs for
envelope, HVAC, and system type
31. ENERGY CODE BASELINE
IECC/ASHRAE SECTION C202
GENERAL DEFINITIONS - STANDARD REFERENCE DESIGN.
A version of the proposed design that meets the minimum requirements
of this code and is used to determine the maximum annual energy use
requirement for compliance based on total building performance.
33. ENERGY CONSERVATION MEASURES
(DESIGN ALTERNATIVES)
ECM1:Wall R-13 batt + 3.80 continuous insulation
ECM2: High Performance Windows U-0.368/SHGC-0.284
ECM3: 10% LPD Reduction (Interior)
ECM4: 15% LPD Reduction (Interior)
ECM5: 30% LPD Reduction (Garage)
ECM6: Roof R-38 continuous insulation
ECM7: Sorbent Air Cleaning Filter System
ECM8: Solar Thermal Hot Water Heating - requires 1,950 SF of roof area (4% of total
area) producing approx. 81,000 kWh/yr
ECM9: Solar PV - requires 5,100 SF of roof area (11% of total area) producing
approx. 111,500 kWh/yr
Net Zero: Solar PV - requires 23,000 SF of roof area (46% of total area) producing
approx. 433,800 kWh/yr
34. ENERGY PERFORMANCE COMPARISONS
-
100,000
200,000
300,000
400,000
500,000
600,000
700,000
Design
Case
Baseline EEM1 EEM2 EEM3 EEM4 EEM5 EEM6 EEM7 EEM8 EEM9
EnergyUse(kWh)
Energy Conservation Measures
COMPARATIVE ENERGY END-USE
Stand-alone Base Utilities
Receptacles - Unconditioned
Receptacles - Conditioned
Fans - Conditioned
Heat Rejection
Pumps
Space Cooling
Space Heating (Gas)
Space Heating (Electric)
Lighting - Unconditioned
Lighting - Conditioned
36. GLASS OPTIONS COMPARISON
Solarban 70XL(2) OptiGray + Clear
U-0.28, SHGC-0.24 and VLT 47%
Solarban 70XL(2) SolarGray + Clear
U-0.28, SHGC-0.20 and VLT 34%
OptiGray + Solarban 70XL (3) Starphine
U-0.28, SHGC-0.29 and VLT 45%
Solar Gray + Solarban 70XL (3)
U-0.28, SHGC-0.24 and VLT 32%
37. PROPOSED DESIGN WINDOW DATA
Nearly 100% of the glazed areas have overhangs with a projection factor >
0.2
The majority of glazing is curtainwall or storefront with aluminum-framed
windows
Total Window-to-Wall Ratio is approx. 15.8%
Approx. 17% of total building glazing is worship clearstory
Orientation Area (SF)
Northeast 0
Southwest 3,265
Southeast 1,060
Northwest 2,615
Total 6,940
38. AUSTIN ENERGY UTILITY REBATES
You are an Austin Energy commercial customer.
You must comply with the Energy Conservation Audit and Disclosure
(ECAD) ordinance if your business is located within the Austin city limits.
(not applicable)
You operate at least four consecutive hours daily between 2:00 p.m. and
8:00 p.m. weekdays, June 1 through September 30. – confirm with ARBC
Facility Manager
TOTAL PROJECT POTENTIAL REBATE – $113,000
TOTAL PROJECT POTENTIAL REBATE (prior to Sept. 30th ) – $147,000
Energy modeling isn’t for me. Isn’t a big firm, big project need?
Energy modeling is too detailed. Can’t we get what we need to know without it?
Will energy modeling detract from my other design goals?
I’m worried that energy considerations and integrated design teams will limit design decisions.
Energy modeling takes time and resources. Can our firm afford to do it?
As noted previously, in its simplest form, an energy model is a calculation engine that accepts inputs such as building geometry, system characteristics, and operations schedules and produces outputs such as performance comparisons and compliance reports. As is true of any family of software, not all energy-modeling tools are equal; they vary in terms of the inputs they accept, the level of sophistication of their engines, and the character of their interfaces, among other things. A familiarity with the range of capabilities found in current energy-modeling tools and the range of uses to which they may be put can help you match the right tool to the job at hand.
Using energy modeling early and often during design offers meaningful value to a range of stakeholders.
The energy modeler’s role is to represent the energy performance implications of project decisions.
TO BE EFFECTIVE, THE MODELER NEEDS TO:
• WORK ALONGSIDE THE PROJECT TEAM TO DEFINE, TARGET, AND UPHOLD PERFORMANCE OBJECTIVES
• MODEL EARLY AND OFTEN
• CONTRIBUTE TO AND COLLABORATE IN DEVELOPING THE TECHNICAL SOLUTION
• STAY ABREAST OF PROJECT DETAILS
Reduced First Cost through Right-Sizing: Energy modeling allows reduction of the safety factors traditionally applied in sizing costly building systems, resulting in a corresponding reduction in initial costs.
Reduced Change Orders: Early scrutiny of, and agreement on, design parameters reduces changes during construction.
Reduced Operating Costs: Energy modeling facilitates design choices that reduce energy use and, accordingly, utility costs.
Reduced Maintenance Costs: More durable materials and more effective systems lower long-term maintenance costs.
Greater Predictability of Operating and Maintenance Costs: The dependability of performance of a well-modeled building enables more cost-effective business and financial decision-making.
Guidance for the Structuring of Real Estate Agreements: Being familiar with the metrics and monitoring of energy systems gives the owner valuable information for structuring leases, maintenance agreements, and the like.
Incentives: Many utilities offer financial incentives for highly energy efficient buildings. Energy modeling can quantify the financial impact of these incentives, as well as provide the evidence of anticipated energy performance the utilities require to receive these incentives.
+ encourage broad staff participation and understanding, rather than relegating modeling to isolated subject experts
+ foster collaborative attitudes and nurture collaborative skills, through active engagement
+ convene face-to-face sessions when possible; they tend to be more effective than web-based approaches
+ follow up with more detailed information, and utilize feedback;
+ remember that, ultimately, this is about architectural practice and delivering better projects, not a new service line.
What if MEP engineer has the scope for modeling? IN COMPARING DIFFERENT PROPOSALS FOR THE SAME MODELING SCOPE OF WORK, THE OWNER SHOULD CONSIDER:
• THE LEVEL OF ACCURACY FOR TRANSLATING ACTUAL OR DESIGN DATA INTO MODEL INPUTS
• THE EXTENT TO WHICH DEFAULT VALUES WILL BE USED IN THE MODEL
• THE PROPOSED WHOLE-BUILDING SIMULATION SOFTWARE
• THE PROPOSED USE OF SPECIALIZED SUPPORT TOOLS FOR STUDYING DAYLIGHTING, NATURAL VENTILATION, OCCUPANT COMFORT, RENEWABLES, ETC.
Recommended Process for Establishing 2030 Baselines:
Use ENERGY STAR Target Finder whenever possible.
Some use types such as laboratories are not available, or cannot be accurately benchmarked, in Target Finder. When possible use alternative benchmarking tools like Labs21 for these use types.
Consider using the EDGE tool for baselining international projects.
Check to make sure your %savings is reasonable.
Recommended Process for Establishing 2030 Baselines:
Use ENERGY STAR Target Finder whenever possible.
Some use types such as laboratories are not available, or cannot be accurately benchmarked, in Target Finder. When possible use alternative benchmarking tools like Labs21 for these use types.
Consider using the EDGE tool for baselining international projects.
Check to make sure your %savings is reasonable.