ASHRAE Journal - December 2019 - 24

TECHNICAL FEATURE

established by the authority
having jurisdiction. The BEMP
certification is administered by
ASHRAE, and the BESA, by the
Association of Energy Engineers.

Climate and Site Analysis

FIGURE 2 Typical energy modeling cycle.

- Reflect Latest Design
- Refine OPR Goals
QA Output
Data
- Narrative
- Inputs
- Outputs Relative
To Goals

Update
Baseline and
Goals

The characteristics of the site
and local climate shall be analyzed
with the ultimate goal of documenting a list of building design
strategies that are adapted to the
- See Table 1 for Each
local conditions. For example,
Modeling Cycle Purpose,
and Applicability
evaporative cooling may apply
to an arid region, but certainly
not to a humid climate. And
water-cooled air-conditioning systems may not be recommended in an arid region.
Appendix A of Standard 209 presents possible sources
of climate data for building energy modeling needed for
this section.

for evaluating these energy efficiency measures.
* Determination of the financial criteria for potential
financial analyses occurring later in the project. Examples
of expected financial analyses to be undertaken include
life-cycle cost analysis and value-engineering analysis.

Benchmarking and Energy Charrette

Energy Performance Goals in OPR

The standard requires that an energy charrette be conducted at the beginning of the project. The energy charrette
must be attended by the design team, the owner, the contractor and, where applicable, the building performance
rating system consultant (e.g., LEED consultant). The
energy charrette has several outcomes, all being essential
strategies for designing a more energy efficient building:
* Documentation of the purposes for including
energy modeling in the project. Energy modeling is
typically used for compliance with an energy code or for
comparative analysis purposes, such as when establishing a model for green building rating. If the purposes
of energy modeling include comparative analysis, the
baseline or baselines to be used are also documented.
* Determination of the energy performance goals
with the help of benchmarking data. Sources of benchmarking data include the Commercial Buildings Energy
Consumption Survey (CBECS) database, the Energy Star
Target Finder, and the DOE Building Performance Database. Appendix B of Standard 209 provides potential
information sources for building energy consumption
data used in benchmarking.
* Creation of a list of potential energy efficiency measures for the project, and determination of the method(s)

Standard 209 requires that the energy performance
goals established during the energy charrette be incorporated into the draft Owner's Project Requirements
(OPR). The OPR is an important document that allows
the project team to track the energy performance goals
throughout the design process. It should be started no
later than during the energy charrette and be updated
as required throughout the design process. Energy performance goals must be documented for the following
building systems and assemblies:
* Building envelope, including roofs, walls, floors,
doors, fenestration, and infiltration rate;
* HVAC systems, ventilation and control strategies;
* Lighting and daylighting systems;
* Service hot-water systems and flow rate restrictors
to hot-water fixtures, fittings, and appliances;
* Equipment related to plug and process energy use.
Appendix D of Standard 209 provides a list of suggested energy performance categories to be addressed
in the OPR, and for each category, one or more recommended metrics.

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D E C E M B E R 2 0 19

Gather Input
Data

Report
Results

Conduct
Analysis

- Project -Specific Data
- Incremental Costs

QA Input
Data

General Modeling Cycle Requirements
This section of the standard addresses requirements

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ASHRAE Journal - December 2019

Table of Contents for the Digital Edition of ASHRAE Journal - December 2019