Every check passes. Nothing here has a locked rotor to publish an inrush figure for, so the absence of one is a fact about the hardware rather than a hole in the library.
Official spec + Derived by WattPair · verified 2026-08-08 · US 120 V unit × inverter window air conditioner
Nominal capacity4,096 Wh
Surge headroom10×+
Running667 Wof4,000 Wcontinuous output
0 – 4,000 W across the rails above
No start-up rail: this load has no locked rotor to publish an inrush for, so no start-up demand was checked.
Two numbers decide this, and readers use them interchangeably: watts are the ceiling on what the inverter holds at any instant, watt-hours are how much energy the battery holds. A machine can have plenty of one and not enough of the other.
The verdict is a calculation, not a lookup. What it will not do is print a runtime, and the reason is specific: this load’s running watts and its duty cycle are not commensurable, so their product is not an average power and will not be printed as one.
Where those numbers come from
A blank is never left blank. A field we have found no figure for says so, and a field whose
sources disagree — two documents, or one document with itself — says that instead of picking
one.
No usable-capacity figure for this machine
EcoFlow states a nameplate watt-hour number for it, and we read 4 of EcoFlow’s own published documents on 2026-08-08 and found no depth of discharge or inverter efficiency for the US 120 V build in them. Dividing the nameplate by this load would be wrong by 20–35% in the flattering direction, so this page shows the nameplate for what it is and refuses to turn it into hours.
Missing: station.usable_capacity_wh
Energy rate instead of a runtime
667 Wh per hourwhile it is actually running
This is the draw while the machine is running and it is deliberately NOT averaged over a duty cycle: for this load the two figures are not commensurable, so their product is not a real quantity. This number multiplies nothing, which is why it survives.
What an inverter window air conditioner demands
Running power667 W Derived from official coefficients · verified 2026-08-03 · medium confidence
What the EcoFlow DELTA Pro 3 offers
Continuous output4,000 W Official spec · verified 2026-08-01 · high confidence
Surge ceiling8,000 W Official spec · verified 2026-08-01 · high confidence
Nominal capacity4,096 Wh Official spec · verified 2026-08-01 · high confidence
Inverter waveformPure sine wave Official spec · verified 2026-08-01 · high confidence
BLUETTI Elite 100 V2 (US 120 V) reaches the same conclusion on an inverter window air conditioner at 1,800 W continuous, and it is $499. Cheaper is only cheaper when the answer is the same — this one is. See that pairing →
The same load on the machines beside it
The same machine on the loads beside it
Where to go next
From the Knowledge channel
An inverter window air conditioner has a dedicated guide: the same records this page computes from, worked through in prose with room for the reasoning a table can only summarise — How do you stay cool in a summer power outage?
Questions people ask about this pairing
Will an EcoFlow DELTA Pro 3 run an inverter window air conditioner?
Yes. 667 W of running draw against 4,000 W of continuous output — 17% of it. The verdict is computed from running watts, and inverter waveform — the working is in the evidence section above.
How long will an EcoFlow DELTA Pro 3 run an inverter window air conditioner?
Not in hours. Hours need an average power, and an average power needs this load's running watts and its duty cycle to describe the same thing — someone checked, and for this load they do not. Multiplying them produces a number that describes nothing. The draw while it is actually running is on the page instead; it multiplies nothing and it is the figure to size against.
Why is there no runtime on a page that says yes?
Because "yes it runs it" and "yes for this long" are two different claims with two different evidence requirements, and this machine only supports the first. The verdict needs a continuous rating and a surge ceiling, which EcoFlow publishes. Hours need a usable-capacity figure, which it does not. Twenty of the twenty-six machines in our library are in that position, and the alternative — nameplate watt-hours divided by label watts — is the single most common wrong number on this topic.