eQUEST, the Quick Energy Simulation Tool, is a free building energy simulation program built on the DOE-2 engine. It lets architects, engineers and students model a building's energy use, including heating, cooling, lighting and equipment, through easy to use wizards and graphical reports. Because it is free and combines a building creation wizard with the powerful DOE-2 calculation engine, eQUEST is one of the most widely used tools for building energy analysis and green building compliance.

eQUEST · Building Energy · Tutorial Part 1

eQUEST Tutorial Part 1: Download, Install & Weather Import

Q: Is eQUEST free to download?

Yes, eQUEST is completely free to download and use. It is distributed from the DOE2.com website as a complete installation package for Windows. There is no licence fee, which is why it is popular with students, small firms and anyone learning building energy modelling. You simply download the installer, save it to your hard drive, and run it to install the program and its DOE-2 simulation engine.

Q: Why do I need a weather file in eQUEST?

A weather file supplies the hourly climate data, such as temperature, humidity, solar radiation and wind, that the simulation uses to calculate a building's heating and cooling loads across a full year. Without a weather file matched to the building's location, the energy results would not reflect the real climate. eQUEST uses weather files in a BIN format, and choosing the correct local file, such as an ISHRAE file for an Indian city, is essential for accurate energy modelling.

Q: What weather file format does eQUEST use?

eQUEST uses weather files in the DOE-2 BIN format. Public weather data is often distributed as EnergyPlus EPW files or, for India, as ISHRAE files, usually inside a zip that also contains a BIN file along with other formats such as DDY, STAT and CLM. When the BIN file is present you can point eQUEST directly at it, and if you only have an EPW file it can be converted to BIN using the DOE-2 weather utilities before importing.

Q: Where can I download weather files for eQUEST?

Weather files are available from several free sources. The EnergyPlus weather website provides EPW files for thousands of locations worldwide. For India, ISHRAE weather files cover many cities and are the standard choice for local energy modelling. These downloads usually come as a zip archive containing the BIN file that eQUEST needs, along with EPW and other supporting formats, so you can extract the BIN and import it directly into your eQUEST project.

Q: What is the difference between the Schematic and Design Development wizards?

The Schematic Design Wizard is meant for the earliest design phase, when information is limited, and uses simpler structures, schedules and assignments for internal loads and HVAC. The Design Development Wizard is for later phases when more detailed information is available, allowing larger and more complex structures, more detailed schedules and more specific HVAC system assignments. Beginners usually start with the Schematic Design Wizard and move to Design Development as their model grows in detail.

Get started with the free eQUEST building energy simulation tool — download it, install it, and import a real weather file so your energy model reflects your building's actual climate.

eQUEST is the most popular free tool for building energy simulation — and this beginner tutorial gets you from zero to a weather-ready project. Whether you're a student, an HVAC engineer, or working toward green-building compliance, the first three things you must master are downloading eQUEST, installing it, and importing the correct weather file for your location. This guide (Part 1 of the series) walks through each step with screenshots from the video tutorial.

What Is eQUEST?

eQUEST (the QUick Energy Simulation Tool) is a free building energy modelling program built on the powerful DOE-2 simulation engine. It combines an easy Building Creation Wizard, an energy efficiency measure wizard, and graphical reporting, so you can estimate a building's heating, cooling, lighting and equipment energy use with professional-level results. It's a cornerstone tool for energy audits, LEED/green-building work, and HVAC design — and it pairs naturally with the other open-source building energy simulation tools.

Step 1: Download eQUEST from DOE2.com

1Go to the DOE2.com eQUEST page

Open DOE2.com and navigate to the eQUEST section. Find the current release (version 3.65) and click the link to download the complete eQUEST installation. Because the installer is large, save the file to your hard drive first rather than running it directly from the browser.

The DOE2.com eQUEST download page (version 3.65).

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Step 2: Install eQUEST

2Run the installer from your hard drive

Locate the downloaded eQUEST 3.65.7175 installer on your desktop or Downloads folder and double-click to run it. Follow the setup wizard, accepting the default options. eQUEST installs the DOE-2 engine plus the Building Creation and Energy Efficiency Measure wizards.

The eQUEST 3.65.7175 installer on the Windows desktop.

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Tip: eQUEST runs on Windows (10/8.1/8/7/XP). If your browser blocks the .msi, right-click the link and choose "Save link as" to download it, then run it locally.

Step 3: Launch eQUEST & Create a New Project

3Open eQUEST and pick "Create a New Project via the Wizard"

Start eQUEST. The Startup Options dialog appears with several choices: open a recent project, open an existing project, create a new project via the wizard, or generate a SkyCalc weather file. Select Create a New Project via the Wizard and click OK to begin building your model.

The eQUEST Startup Options dialog (build 7175, DOE-2.2).

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Step 4: Choose the Wizard Type

4Schematic Design vs Design Development

eQUEST asks "Which Wizard?" Choose:

Wizard	Use it for
Schematic Design Wizard	Earliest design phase; smaller/simpler structures, simple schedules and HVAC. Best for learning.
Design Development Wizard	Later phases; larger/complex structures, detailed loads, schedules and HVAC assignments.

The "Which Wizard?" dialog — Schematic Design vs Design Development.

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Step 5: Get a Weather File for Your Location

A weather file gives the simulation the hourly climate data (temperature, humidity, solar, wind) it needs to calculate a full year of heating and cooling loads. eQUEST uses the DOE-2 BIN format.

5Download & extract your city's weather file

Download a weather file for your site — for India, an ISHRAE weather file (e.g. Jaipur), or an EnergyPlus EPW file for anywhere in the world. The download is a zip that contains several formats. Extract it and locate the .bin file — that's the one eQUEST imports (alongside .epw, .ddy, .stat, .clm, etc.).

An ISHRAE 2014 weather data zip for Jaipur, India — note the .bin file eQUEST needs.

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Key point: if your download only has an .epw file (common for EnergyPlus data), convert it to .bin with the DOE-2 weather utility before importing. When a .bin is already in the zip, you can use it directly.

Step 6: Import the Weather File into the Wizard

6Set the project details and browse to the weather file

On Wizard Screen 1 of 43 (General Information), fill in the Project Name, Building Type (e.g. Office Bldg, Two Story), Location Set (User Selected), building area and number of floors. Then click the browse button (…) next to the Weather File field and select your city's .bin file — linking your model to real local climate data.

eQUEST Schematic Design Wizard, Screen 1 — General Information with the Weather File browse button.

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Why this matters: the weather file drives every load calculation. Getting the right local climate in now means your later results — heating, cooling and energy use — reflect reality. It complements a manual HVAC load calculation and your building envelope's U-value / R-value.

What's Next in the Series

With eQUEST installed and your weather file imported, you're ready to build the model. Coming up in this series:

Defining building geometry, footprint and zoning in the wizard
Setting the envelope (walls, roof, glazing) — where U-values matter
Internal loads, occupancy and schedules
HVAC systems and running the simulation
Reading the energy results and reports

For the bigger picture of how eQUEST fits among other tools, see our guide to the top open-source building energy simulation tools, and for airflow-level detail, natural vs mechanical ventilation.

Authoritative external references: DOE2.com — eQUEST (official download), and the EnergyPlus Weather Data (EPW files worldwide).

Frequently Asked Questions

What is eQUEST?

A free building energy simulation tool built on the DOE-2 engine, with wizards and graphical reports for modelling heating, cooling, lighting and equipment energy use.

Is eQUEST free to download?

Yes — completely free from DOE2.com for Windows. No licence fee, which is why it's popular with students and small firms.

Why do I need a weather file in eQUEST?

It supplies the hourly climate data the simulation needs to compute a full year of heating and cooling loads. Without the right local file, results won't reflect the real climate.

What weather file format does eQUEST use?

The DOE-2 BIN format. Public data often comes as EPW (EnergyPlus) or ISHRAE zips that include a BIN file; use the BIN, or convert an EPW to BIN.

Where can I download weather files for eQUEST?

The EnergyPlus weather site (EPW worldwide) and, for India, ISHRAE weather files. The zip usually contains the BIN file eQUEST needs.

What is the difference between the Schematic and Design Development wizards?

Schematic is for early, simpler models; Design Development is for later, more detailed models with complex structures, schedules and HVAC. Beginners start with Schematic.

Conclusion

You've completed the essential first steps of building energy modelling in eQUEST: download, install, and weather-file import. With the DOE-2 engine installed and real local climate data linked to your project, you have the foundation for an accurate energy model. Follow the steps and screenshots above, grab the correct .bin weather file for your city, and you're ready to start building geometry in the next part of this series.

For more building energy, HVAC and simulation tutorials plus free engineering calculators, explore Free CFD Tutorial. If this tutorial helped you, please share it and subscribe to the CFD Expert channel for the video version.

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