Models as representation of things

When I was a kid

Models of how things look

• Architectural models

Working models

• Working models

• Bench test, Prototypes

Process Models

Math & Stat Models

http://www.nexyad.net/HTML/e-book-Matematical-Model.html

Models and

Reality

•Do not mistake models for reality

•Varying degrees of correspondence to reality

Using Models

• Forward, physical principles

• Inverse

Another Comparison of Forward and Inverse

Models

Engineering analysis - Thermodynamic boundary conditions

Thermal, Pressure, Moisture Internal Gains

Load CalculationsEnvelope conduction Ventilation / InfiltrationRadiation

Humidity control & HVAC Processes

Dynamics8760 modelsLags, interactions

How can we look at buildings as objects of study?

Computer Applications

• Building as object

• Thermodynamic process

• Energy outcomes

Energy Model Outcomes

What do we want to know?

• Will our design provide adequate conditioning?

• How much energy? Daily, monthly, annually

• Where, for what? End-Uses

Go to EQ Tutorial, page 122 ff

Energy models - history

Core calculation engines• DOE-2

• BLAST

• TRACE

• TRNSYS

Interfaces and "shells”• Commercial: IES, AutoDesk

suite• Open Access: Simergy, Open

Studio

Code Compliance Programs• ResCheck and ComCheck

http://www.bembook.ibpsa.us/index.php?title=History_of_Building_Energy_Modeling

[ENERGY PLUS]

Uses of energy modelsCompare alternative schemes

• Code compliance – compare design to a base case

• Design studies and decisions

Predict outcomes of changes in building systems

• Energy audits

Energy models - dangers

• Incorrect application -- embedded calculations don't match situation

• False precision

• GIGO

• Lulling the analyst into acceptance

Syllabus review

• Basic course information

• Learning Objectives

• Requirements and Evaluation

• Lecture-Lab class structure

• Weekly Reading