Chiller Selection Software — IPLV/NPLV the Way AHRI 550/590 Actually Says

If you've spent any time reviewing chiller submittals, you've seen the move: a glossy datasheet front-and-centering a 0.55 kW/TR full-load number, with the IPLV figure tucked in fine print on page four. The customer signs. Two years later, the energy bill tells a very different story — because the chiller spent 5% of its life at full load and 95% of it somewhere on the part-load curve.

A purpose-built Chiller Selection Software exists because that gap is real, expensive, and entirely avoidable.

What chiller selection actually requires

AHRI 550/590 specifies how chiller part-load performance must be calculated and reported. In practice, a defensible selection produces:

• Full-load efficiency at AHRI rating conditions — the headline number.
• IPLV (Integrated Part-Load Value) — a weighted average across 100% / 75% / 50% / 25% load using AHRI's standard condenser-water trajectory.
• NPLV (Non-standard Part-Load Value) — same idea, but using your project's condenser-water trajectory, cooling tower behavior, and ambient bin profile.

NPLV is the number that actually matters for lifecycle cost. A chiller with a worse IPLV but a better NPLV at your site is the right pick — and only a real selection tool can show you that.

How MileSoft handles it

The MileSoft Chiller Software is built around AHRI 550/590-compliant performance curves and gives you:

1. Full-load + IPLV + NPLV in one pass, with NPLV configurable to your project's condenser water and bin profile.
2. Side-by-side comparison of multiple chillers and configurations (parallel, primary-secondary, variable primary) against the same load profile.
3. Hourly bin energy modeling so the kWh number you put in front of the customer is actually defensible.

The features engineering teams quietly rely on

• Bin-weather libraries for major Indian, Middle East, and global cities — no more chasing weather files.
• Refrigerant TEWI calculations for the customers who care (and increasingly, the customers who have to care under regulations like F-gas).
• Branded submittal output with the calculation methodology disclosed — so it survives consultant review.

Where it fits

Chiller selection is the highest-impact decision in a central-plant project. The natural complements:

• AHU Selection Software for the air-side equipment that lives downstream,
• FCU Selection Software for the terminal units,
• Lifecycle Cost Analysis — the place where the IPLV-vs-NPLV story turns into a board-room story.

The bottom line

Selling on full-load efficiency is selling a fiction. Customers know it. Consultants know it. Energy auditors know it. The gap between "looks good on paper" and "actually performs in the building" is the gap a real chiller selection tool is built to close.

Book a 30-minute demo. Bring last quarter's biggest chiller win — we'll re-run the selection on NPLV at your site's ambient profile and show what the actual annual kWh number is.