Using Notepad++, there is a very efficient way to compare two eQUEST *.pd2 or *.inp files. This also works with EnergyPlus, and basically any two text based files.

Notepad++ is a lightweight, must-have program for energy modelers. I've fixed numerous complex eQUEST issues using its tools. It's like WordPad, but on steroids (and yet somehow just as fast or faster).

How to Compare Two eQUEST Files in Notepad++ (Step-by-Step)

The goal is simple: open two files side-by-side and highlight the differences so you can instantly see what changed.

Step 1: Install the Compare plugin (one-time setup)

1. Open Notepad++
2. Go to Plugins → Plugins Admin...
3. Search for Compare (the plugin is usually called Compare)
4. Check the box and click Install
5. Restart Notepad++ if prompted

Once installed, you'll see Compare options under the Plugins menu.

Step 2: Open both files

1. Open your first file: File → Open (example: Baseline.inp)
2. Open your second file: File → Open (example: Proposed.inp)

If the files are huge, let them fully load before running the compare.

Step 3: Run the comparison

1. Click inside the tab of the file you want to treat as the “original”
2. Go to Plugins → Compare → Compare

Notepad++ will split the window and highlight differences.

• Added lines = present in one file but not the other
• Changed lines = same line number but different text
• Deleted lines = removed from one file compared to the other

Step 4: Jump through the changes quickly

These two buttons are what make this tool so fast:

• Plugins → Compare → Next diff
• Plugins → Compare → Previous diff

You can fly through a large eQUEST file in seconds and see exactly what changed.

Practical Tips for Comparing eQUEST INP Files

Tip A: Ignore “noise” formatting differences

Sometimes you’ll get false differences because one file has different spacing or tabs. Try:

• View → Show Symbol → Show White Space and TAB
• Or run a quick cleanup: Edit → Blank Operations (ex: trim trailing spaces)

Tip B: Watch out for line endings

If one file was created on a different system, line endings can cause the compare to look messy.

Check the bottom right of Notepad++ for Windows (CRLF) vs Unix (LF). If needed:

• Edit → EOL Conversion → Windows (CRLF)

Tip C: Use “Find” to isolate a specific object

If you’re troubleshooting one item (like a schedule or curve), use Find:

• Search → Find
• Search for the object name (examples: "SCH", "CURVE", "CHILLER", "PUMP")

This is especially helpful when a client says “I didn’t change anything” and you want to confirm whether they changed a curve, schedule, or a control setting.

What this is useful for in real modeling

• Confirm whether something changed between “version 1” and “version 2” of a model
• Quickly check why energy use shifted after “minor tweaks”
• Verify baseline vs proposed differences
• Catch silent changes in curves, schedules, pumping, and control logic

If you're doing program compliance (LEED, 179D, incentives, etc.), comparing files is one of the fastest ways to protect yourself from fragile savings and reviewer questions.