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The Oil-Free Payback Decoder
Energy life-cycle cost computed with the U.S. DOE / FEMP published method: 23-year chiller service life, your run hours, your tariff. No vendor percentage — you can reproduce every line.
Read this before you run it.
Reviewing GSA’s evaluation, commissioning engineers report the technology was judged cost-effective for new installations and end-of-life replacements, but was not recommended for retrofit because replacement cost outweighed the efficiency gain. If your existing chiller has years of life left, this calculator will flatter a decision you should not make yet.
Method & Assumptions
Method. Annual energy = capacity (TR) × kW/ton × run hours — the same formula FEMP uses in its published chiller worked example.
FEMP’s default assumptions are 2,000 run hours per year, a 23-year service life, and 9.9 ¢/kWh (average U.S. federal facility electricity price, July 2024). Results below are undiscounted; FEMP applies a 3% discount rate per NISTIR 85-3273-39. Apply your own cost of capital before presenting to finance.
Defaults explained. 0.319 kW/ton is the IPLV of the KALXCWG 600EVD. 0.540 kW/ton is the best-case IPLV of the ASHRAE 90.1 standard-centrifugal class (reported range 0.54–0.78). Energy savings only — avoided oil-management consumables and their labour hours sit on top of these figures, not inside them.
System Parameters
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