Building Energy Simulation

 Energy simulation is a computer based analytical tool that helps to evaluate the energy performance of building. This helps to do modifications in the in the designs of the building before its construction.

Use of energy simulation also becomes important to show compliance with the ASHRAE in case of LEED certification and with ECBC in case of GBCI and GRIHA certification.

Building energy modelling has become an important aspect to analyse an improved building energy efficiency. Energy modelling is used in new construction as well as retrofitting of existing buildings design. In order to comply with LEED certification building energy efficiency is compared with a base case model having standards defined by ASHRAE.

Once the simulation is completed the user can design, optimize various building elements and can evaluate the effect of various changes in the building designs and its implication in overall energy consumption.

There are many energy modelling tools that are extensively used for the building energy modeling are described below-

eQuest DOE 2 Energy Simulation Tool

eQUEST is the DOE 2 engine, most popular energy modelling program in existence. It’s used by energy modellers and engineers all over the world. It can be used at every stage of building development, from the early designs to final stages.

eQUEST allows us to import building geometry from architectural models in AutoCad. Or we can construct a building envelop within the program. From there we can run simple simulations or very complex building models.

eQuest has a function where Energy Efficiency Measures can be created and manipulated to see the resulting changes to a model. • eQuest also has a life cycle cost analysis tool for each EEM applied to the model.

 There are three input wizards in eQUEST that all have differing levels of complexity, or you can use the detailed DOE-2 interface. They wizards are as follows:

Schematic Design Wizard (simple inputs)

Design Development Wizard (detailed input) and

Energy Efficiency Wizard.

Each wizard has broad default inputs that are based off California Title 24 building energy code. Long-term average weather data are available via automatic download from within eQUEST.

A snapshot is shown below with a model designed with propose case parameters using Building Creation Wizard mode and in Detailed data mode.

Building components with all the specifications and suitable properties are designed provided with different input parameters.

HVAC system is also designed with specific parameters and internal loads are also assigned as per DBR provided by owner.

After all the necessary work simulation is done.

eQUEST supports a number of graphical results. eQUEST provides outputs for single-run results, comparative results and parametric reports.

A snapshot of summery result of annual electric consumption one of our project is shown below

The detailed Building Utility Report can also be downloaded in pdf format.

EnergyPlus Simulation Tool

EnergyPlus™ is a whole building energy simulation program that engineers, architects, and researchers use to model both energy consumption—for heating, cooling, ventilation, lighting and plug and process loads—and water use in buildings. Important features and capabilities of EnergyPlus include:

• Integrated, simultaneous solution of thermal zone conditions and HVAC system response that does not assume that the HVAC system can meet zone loads and can simulate un-conditioned and under-conditioned spaces.
• Heat balance-based solution of radiant and convective effects that produce surface temperatures thermal comfort and condensation calculations.

• Sub-hourly, user-definable time steps for interaction between thermal zones and the environment; with automatically varied time steps for interactions between thermal zones and HVAC systems. These allow EnergyPlus to model systems with fast dynamics while also trading off simulation speed for precision.
• Combined heat and mass transfer model that accounts for air movement between zones.
• Advanced fenestration models including controllable window blinds, electrochromic glazings, and layer-by-layer heat balances that calculate solar energy absorbed by window panes.
• Illuminance and glare calculations for reporting visual comfort and driving lighting controls.
• Component-based HVAC that supports both standard and novel system configurations.
• A large number of built-in HVAC and lighting control strategies and an extensible runtime scripting system for user-defined control.
• Functional Mockup Interface import and export for co-simulation with other engines.
• Standard summary and detailed output reports as well as user definable reports with selectable time-resolution from annual to sub-hourly, all with energy source multipliers.

EnergyPlus is a console-based program that reads input and writes output to text files. It ships with a number of utilities including IDF-Editor for creating input files using a simple spreadsheet-like interface, EP-Launch for managing input and output files and performing batch simulations, and EP-Compare for graphically comparing the results of two or more simulations. Several comprehensive graphical interfaces for EnergyPlus are also available. DOE does most of its work with EnergyPlus using the OpenStudio software development kit and suite of applications.

DOE releases major updates to EnergyPlus twice annually.

EnergyPlus is free, open-source, and cross-platform.

source- energyplus.net

TRACE 700

TRACE 700 is a Windows based program used to construct a virtual building, calculate its air conditioning loads and simulate its hourly

operation over the course of 1 year. It can also perform a life cycle cost analysis.

It helps HVAC professionals optimize the design of a building’s heating, ventilating and air-conditioning system based on energy utilization and life-cycle cost.

TRACE 700 helps you compare the energy and economic impact of building-related selections such as architectural features, HVAC systems, HVAC equipment, building utilization or scheduling, and financial options.

source- www.trane.com

Compared with other economic analysis software, TRACE 700 advantages include:

TRACE 700 enables building designers to optimize the building, system and equipment designs on the basis of energy utilization and life-cycle cost. The Trane software for TRACE 700 facilitates analysis of the energy and economic effects of virtually any chiller plant configuration by allowing users to manipulate a wide range of variables and create a profile of their specific building.

Select System Features

Underfloor air distribution systems, Active and passive chilled-beam systems, Displacement ventilation systems and many more

Select Equipment Features

Chiller Plant Wizard (decoupled arrangement, parallel series, variable-primary flow, switchover control), Cogeneration, Thermal energy storage

Direct-fired absorption chillers,Low-flow chilled water,Free cooling (plate-and-frame, refrigerant migration, strainer cycle, double-bundle heat recovery),

Cooling tower with VFD,Chiller-tower optimization,Domestic hot water andSophisticated evaporative cooling. 

Multiple Equipment Types

Air/water-cooled chillers, Air/water-cooled unitary,Water-source heat pumps,Ground-source heat pumps,Boilers,Electric resistance heat & Gas-fired heat exchanger

Equipment Library

Default Equipment, ASHRAE Standard 90.1-2004, ASHRAE Standard 90.1-2007& ASHRAE Standard 90.1-2010.