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Free calculator · drying

Drying equipment power calculator will the panel run it?

A drying setup that trips breakers all night dries nothing, and the tech gets blamed for it. Enter your air movers and dehumidifiers and the circuits available, and this tool packs the load under the NEC 80 percent rule, tells you whether the panel can run it, and sizes a generator or spider box when it cannot. It outputs the temporary-power line items so that power gets billed.

Method

How the circuit plan is built

Every piece of drying equipment has an amp draw, taken from manufacturer spec sheets for the common restoration bands. Air movers are light, dehumidifiers are heavy, and an electric heater or air scrubber sits in between. The tool adds up the connected load and converts it to kilowatts so you can see the total the loss will pull.

Then it packs the units onto the circuits you have available, but only to 80 percent of each breaker rating. That is the NEC continuous-load limit, and it exists because drying runs for hours without cycling off. A 20 amp circuit is planned to 16 amps of equipment, not 20. When the equipment will not fit the circuits, the tool sizes a generator in kilowatts and lists the temporary-power distribution as real Xactimate items, so a loss that outruns the panel gets the temp power it needs on the estimate instead of a tech chasing tripped breakers at 2 a.m.

If you sized the drying on the water mitigation calculator, you do not re-enter anything. The "Can the panel run this setup?" panel on that page carries the equipment straight into this one.

The engine behind this calculator

This same math runs inside AI Estimate Assistant

AI Estimate Assistant, from Antero Trail, turns field notes, photos, and floor plans into carrier-ready Xactimate estimates. The calculator on this page is one piece of that engine, pulled out and made free. In the app, the drying setup and its power check come out of the flood intake together. When a loss outruns the panel, the temporary-power lines land in the estimate automatically.

Try AI Estimate Assistant free See what the app does
FAQ

Common questions

How many air movers can I run on one circuit?
It depends on the air mover and the breaker. A typical axial air mover draws close to 1.5 to 2 amps and a centrifugal one draws more, so a 15 amp circuit derated to its 80 percent continuous limit of 12 amps holds several movers, not a whole room. Dehumidifiers are the heavy draw and often want their own circuit. The tool packs your specific equipment onto your circuits and shows what fits where.
What is the 80 percent rule?
The National Electrical Code treats drying equipment as a continuous load because it runs for hours without stopping. A continuous load can only use 80 percent of a circuit rating, so a 15 amp circuit is planned to 12 amps and a 20 amp circuit to 16. Loading a circuit to its full rating trips the breaker overnight and dries nothing. The calculator applies the derate automatically.
When does a water loss need a generator or spider box?
When the equipment draws more current than the available circuits can supply. A large loss with dozens of air movers and several dehumidifiers can exceed a residential panel, so the drying either trips breakers or never gets set. The tool detects the overflow, sizes a generator in kilowatts, and lists the temporary-power distribution as real Xactimate items so the temp power is billed instead of eaten.
Can I bill temporary power on a water loss?
Yes, when the equipment count exceeds what the building can supply. Temporary power is a real cost, and an estimate that sets 40 air movers on a house without a generator line is not a real estimate. The tool outputs the generator, spider box, cable, and usage as Xactimate TMP items that price at import.
Why does the calculator ask how many circuits are available?
Because it will not assume. A drying plan lives or dies on the power available, and guessing unlimited circuits produces a plan that fails on site. If you leave the circuits blank the tool asks rather than pretending. Enter the circuits the drying can actually use, and it plans against reality.
Sources

Sources

Related tools

Size the drying equipment first on the water mitigation equipment calculator, then check the power here. For rooftop and access equipment, see the crane cost estimator.

These calculators produce planning estimates from published public rate schedules. They are not a formal quote. Confirm equipment, access, and pricing with a licensed operator or rental yard before you rely on any number for an estimate.