1
Voltage Gate
PASSDevice output type must match generator output.
120V required -> 120V/240V available
Yes, the Delta Pro Ultra can run a Box Fan (20-inch)
This pairing clears the safety headroom. Required ~96W running and 191W surge; the Delta Pro Ultra is rated 6000W / 12000W.
Power Margin Analysis
6000W / 12000W Capacity Running 5904W headroom
96W required
Surge 11809W headroom
191W required
Decision Gate Waterfall
Same decision gates as the engine: voltage, running, surge. Runtime is shown as operational context.
2
Running Gate
PASSContinuous draw with safety buffer applied.
96W required -> 6,000W available (5,904W headroom)
Required 96W required
Available 6,000W
3
Surge Gate
PASSStartup peak with safety buffer applied.
191W required -> 12,000W available (11,809W headroom)
Required 191W required
Available 12,000W
4
Runtime Insight
INFORuntime context only. It does not change the electrical compatibility verdict.
Continuous estimate: 51.8h
Device profile reference: up to 8h per day.
Power bars show required versus available output for each gate.
View full compatibility reportDecision Snapshot
Quick compatibility, required headroom, and model-specific context at a glance.
⚡
6000W
Running Power
🔋
6144Wh
Capacity
⏱️
~51.8h
Est. Runtime
☀️
5600W
Solar Input
Quick Compatibility Check
- 1 Running headroom: target 96W; generator provides 6000W.
- 2 Surge headroom: target 191W; generator provides 12000W.
- 3 Tip: leave headroom for startup spikes and warm conditions.
Model-Specific Results
3 of 3 models are SAFE or TIGHT. Most demanding model: Lasko B20200 (20-inch Box Fan) (166W surge).
| Model | Running | Surge | Verdict | Runtime | Source |
|---|---|---|---|---|---|
| Lasko B20200 (20-inch Box Fan) | 83W | 166W | Safe | ~51.8h | Engineering Est. |
Show expert analysisTechnical: **Running load:** 83 W. **Surge:** 166 W (estimated 2x startup for shaded-pole motor). **Voltage:** 120 V AC. Small shaded-pole fan motors produce a brief inrush at startup that is typically 2x running — far less than the 3x NEC standard for larger motors. Field note: Box fans are among the easiest appliances to run off-grid. Even with the 2x startup surge, any power station rated 200W+ handles this fan comfortably. Will this fan drain my power station quickly? At 83W continuous, an 8-hour overnight run consumes ~664 Wh. A 1000Wh power station handles it with margin to spare. | |||||
| Lasko B20500 (20-inch Box Fan) | 72W | 144W | Safe | ~59.7h | Engineering Est. |
Show expert analysisTechnical: **Running load:** 72 W. **Surge:** 144 W (estimated 2x startup). **Voltage:** 120 V AC. Slightly lower draw than the B20200 — same motor technology, lower speed setting or blade design. Field note: At 72W, this is the lightest box fan in the comparison. Perfect for overnight use on a portable power station — a 500Wh unit runs it for nearly 7 hours. Can I run this fan overnight on a 500 Wh power station? Close — 8 hours at 72W needs 576 Wh. With inverter losses (~70% usable), a 500Wh station runs it for about 5 hours. A 750Wh+ station covers a full night. | |||||
| Lasko 3733 (20-inch Box Fan) | 80W | 160W | Safe | ~53.8h | Engineering Est. |
Show expert analysisTechnical: **Running load:** 80 W (high speed, top of 50-80W range). **Surge:** 160 W (estimated 2x startup). **Voltage:** 120 V AC. Variable speed range means actual draw depends on setting — low speed draws as little as 50W. Field note: If running on battery, use a lower speed setting. Dropping from high (80W) to low (50W) extends runtime by 60% — a meaningful difference on a single charge. How long can I run this fan on low speed? At 50W on low speed, a 1000Wh power station (700Wh usable) runs it for about 14 hours. High speed (80W) cuts that to about 9 hours. | |||||
How This Pairing Performs Across Our Database
This unit ranks #32 of 33 compatible generators for this device by buffered margin (Overkill class).
How Box Fan (20-inch) Performs Across 33 Tested Generators
33 of 33 generators are SAFE+TIGHT for Box Fan (20-inch).
33
Safe+Tight
Safe 33 (100%)
Power Comparison: EcoFlow Delta Pro Ultra vs Top Alternatives for Box Fan (20-inch)
EcoFlow Delta Pro Ultra Safe Overkill
Current unit
Running 6,000W
Surge 12,000W
Fit class uses buffered needs (running and surge) for this device.
Specs & Surge Analysis
Heating & Cooling
Box Fan (20-inch)
Hot Weather Ventilation
Select Your Model:
83W
Running
166W
Surge
120V
Required
True Surge™ Analysis
Safety Buffer: +15% Running Power Usage 2% Utilization
96W required 6000W Capacity
5904W headroom
Surge/Startup Peak 2% Utilization
191W required 12000W Capacity
11809W headroom
Voltage Match 120V ↔ 120V/240V ✓
⚠️
Before You Buy: Connection Check
Installation warning
These systems are often hardwired to a home panel. To run them from a portable station, you may need a transfer switch installed by an electrician. You cannot just plug it in.
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Generator Insights
With 12000 watts of surge capacity, this system can handle typical startup loads for central air compressors, well pumps, and other motor-driven equipment common in residential settings. The 6000-watt continuous rating supports sustained operation of multiple high-draw appliances simultaneously. The 6144 Wh capacity provides meaningful runtime for essential circuits during grid outages.
This unit uses lithium iron phosphate (LFP) chemistry, known for stable thermal behavior in stationary storage applications. The system is designed with internal protections typical of grid-tied and off-grid battery platforms. Source: EcoFlow DELTA Pro Ultra User Manual (manufacturer documentation).
Extend Runtime with Solar
Keep your Box Fan (20-inch) running with solar • MPPT: 80– 450V • Max: 5600W
Official EcoFlow
400W Panel
1 Hour Sun =
Runs Indefinitely
Plug & Play
Full in ~21.9h 
Smart Value Anker
400W Panel
1 Hour Sun =
Runs Indefinitely
Plug & Play
Full in ~21.9h 
Smart Value Bluetti
350W Panel
1 Hour Sun =
Runs Indefinitely
Plug & Play
Full in ~25.1h Technical Analysis
Spec-Based • No GuaranteesTechnical Breakdown
Running load: 83 W (worst case). Surge: 166 W (2x startup, small fan motor policy for shaded-pole motors). Voltage: 120 V AC required. Box fans use small shaded-pole motors with a brief 2x inrush at startup — much lower than the 3x NEC standard for larger motors.
Expected Behavior
Estimated runtime: ~51.8h. Draws 72-83W steady depending on model. 8 hours daily operation consumes 576-664 Wh. Startup inrush is brief (<1 second) and typically 2x running.
Field Note
Box fans are ideal off-grid appliances. Low running watts, minimal surge, and long daily use. Size your power station for runtime (capacity in Wh), not wattage — any 200W+ station handles the load.
Frequently Asked Questions
Can the EcoFlow Delta Pro Ultra power a Box Fan (20-inch)?
Yes. The EcoFlow Delta Pro Ultra provides 6000W running / 12000W surge. The Box Fan (20-inch) needs 96W / 191W (including 15% buffer). That leaves 5904W of running headroom and 11809W of surge margin.
How long will the Delta Pro Ultra run a Box Fan (20-inch)?
Approximately 51.8 hours, based on the Box Fan (20-inch)'s 83W draw and the Delta Pro Ultra's 6144Wh capacity (70% usable after real-world losses).
What Else Can You Run?
With 955W allocated to the Box Fan (20-inch), the Delta Pro Ultra still has ~3762W of margin. These devices could run simultaneously:
💡
LED Lamp
10W
🌀
Box Fan (Medium)
60W
🔥
Space Heater (Eco)
750W
📺
55' LED TV
80W
📡
Wifi Router
15W
🩺
CPAP (No Humidifier)
40W
Power Tip: To get the most out of your Delta Pro Ultra, keep it in a well-ventilated area. Extreme temperatures can slightly reduce the efficiency of the LFP/NMC cells.
Compare all 33 generators for the Box Fan (20-inch)
Ranked by budget, runtime, and overall compatibility.
Technical Sourcing & Verification
ID: ecoflow-delta-pro-ultra-box-fan-20inch 🏛️ Device Data Source
Engineering Est. Safety Factor Applied
Derived from variant list (max of variants). Running worst case = Lasko B20200 (83W OEM). Surge worst case = Lasko B20200 (166W). Small fan motor policy: 2x startup for shaded-pole motors.
⚡ Generator Specs Source
OEM Verified
EcoFlow DELTA Pro Ultra User Manual
Methodology informed by US Department of Energy (DOE) & EIA references where applicable.
Our methodology →
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