Choosing a Generator for a Bounce House Rental Fleet

A commercial inflatable blower is rated in horsepower, but amps are the number that decides whether it runs. Published running draw for 1 to 2 HP units runs from 7 to 13 amps at 120 volts. Read the nameplate on your own blowers, because two blowers sold as "1.5 HP" can differ by more than 2 amps.

If you are still building the fleet, blowers and cords are one line in the startup budget in how to start a bounce house rental business. Here is what the manufacturers publish:

To turn amps into watts for planning, multiply by 120 volts: a 13 amp blower is about 1,560 watts. That slightly overstates what a motor consumes, which is the safe direction to err.

Startup draw

None of these product pages publish a startup figure. Michigan State University's tech note on induction motors puts inrush at five to eight times running current, lasting from a fraction of a second to a few seconds. The same note explains that a fan load needs little torque to start, which shortens that spike. JumpOrange, a commercial inflatable maker, plans on roughly double the running wattage at startup.

Either way, start blowers one at a time, largest first, each at full speed before the next.

A household outlet does not carry its breaker rating all day. Under National Electrical Code Table 210.21(B)(2), a receptacle on a circuit with two or more outlets may carry at most 80 percent of its rating in plug-in load: 12 amps on a 15 amp receptacle, 16 amps on a 20 amp one.

Limits from NEC Table 210.21(B)(2) via UpCodes. Blower amps from the table above.

Three consequences for a rental crew:

• A 2 HP blower does not belong on a 15 amp circuit. Its 13 amps is over the limit before anything else on that circuit turns on.
• Two blowers on one circuit is the exception. Only the lightest 1 HP units fit, on a 20 amp circuit with nothing else running.
• The customer's circuit is not empty. A garage freezer or a pool pump can share it, which is why the safety checklist says to confirm the blower is on a dedicated circuit before you leave. A blower that trips the breaker is on a shared or undersized circuit.

In Canada the Canadian Electrical Code governs instead. Confirm its limits with a licensed electrician before you publish an outlet rule there.

Size the generator on its rated (running) watts, not its peak, and keep your total running load at or below 80 percent of that rating. Inflatable Doctor puts it as buying 25 percent more wattage than you calculate, which is the same thing.

The calculation is three steps: add the nameplate amps of every blower, multiply by 120 volts, then divide by 0.8.

Minimum rated watts is our arithmetic from the blower amps above. Generator ratings from Honda and Generac. JumpOrange figures from its 2026 generator guide.

The two columns disagree. The minimum column covers running load with headroom and assumes you start blowers one at a time. JumpOrange's figures are larger because they build in starting surge and room for other equipment. Treat the minimum as the floor, never the target, and put each blower on its own generator receptacle rather than splitting one with an adapter.

To run the numbers for your own mix, with speakers or a concession machine on the same generator, our sister site WattSimple has a free bounce house generator calculator. It takes each blower's nameplate amps and returns the running and starting watts, how many household circuits the blowers need and the cord gauge for your run. It counts one blower's start surge at twice its running draw, so its starting figure lands between the two columns above.

Inverter generators are quiet, light and fuel efficient at part load, which suits backyards and parks. Conventional open frame generators are louder and heavier but come in larger sizes, which suits a multi unit event.

Two things in that table matter for inflatables:

• Inverter surge headroom is small. The EU2200i peaks only 22 percent above its rating. If a blower trips an inverter on startup, that generator is too small for that blower, whatever the running arithmetic says.
• Noise decides where you can work. JumpOrange puts inverters at 50 to 65 dB against 70 to 80 dB for conventional units, and notes that noise ordinances at residential and indoor events may require an inverter. Park permits are covered in licenses, permits and inspections.

A generator that runs dry deflates the bounce house with children inside. Plan runtime against the rental window, not the party, because the blower runs from setup until pickup. Runtime depends on load. Using Honda's published figures:

• One 1.5 HP blower on an EU2200i is about 73 percent of its rated output (1,320 of 1,800 watts). Runtime sits nearer the 3.2 hour rated load figure than the 8.1 hour quarter load figure, so an eight hour rental needs at least one refuel.
• The same blower on an EU3000iS is under half load, so a full 3.4 gallon tank sits between Honda's 6.9 and 19.6 hour figures. That covers an eight hour rental with margin.

For larger setups, JumpOrange estimates a 5,000 watt generator at half load burns 0.5 to 0.7 gallons an hour, 4 to 5.6 gallons across an eight hour event.

Refueling is not a top up. OSHA's portable generator fact sheet says to shut the generator down and let it cool first, because fuel spilled on hot engine parts can ignite. The unit deflates and the riders come off. Size the tank for the whole window, or make the refuel your crew's job rather than the customer's.

Every foot of cord costs voltage, and a motor starved of voltage draws more current and runs hotter, per the Michigan State tech note. Keep total voltage drop under 3 percent, the figure the NEC recommends for branch circuits in an informational note to Section 210.19. At 13 amps that means 12 gauge to 50 feet and 10 gauge beyond it.

Voltage drop on a 120 volt run, extension cord only:

Calculated from NEC Chapter 9 Table 8 resistance for stranded copper at 75°C (3.14, 1.98 and 1.24 ohms per 1,000 feet), counting both conductors. At 10 amps, 12 gauge reaches 3.3 percent at 100 feet.

Manufacturers print the same answer. The MoonwalkUSA owner's manual calls for a three wire cord of at least 12 gauge for 50 feet. JumpOrange calls for 10 gauge for 1.5 to 2 HP, one gauge heavier past 50 feet, and never more than 100 feet of cord to a commercial blower.

Two details catch crews out:

• The blower's own cord counts. The B-Air KP-1.5 ships with a 25 foot, 14 gauge cord, and a cord like that on a 13 amp blower uses about 1.7 percent of your 3 percent budget by itself. The extension has less to spend than the table suggests.
• Outdoor rated, three prong, undamaged. OSHA's fact sheet says to use grounded cords rated for the load, and to replace frayed or underrated cords with heavier gauge ones. JumpOrange says to look for a W or W-A on the jacket, which marks outdoor use.

Count cords and spares at the shop with the unit, as in planning a Saturday.

Every blower plugs into a GFCI, a ground fault circuit interrupter that cuts power when current leaks to ground, as it can through wet grass or a nicked cord. The MoonwalkUSA manual says to connect a GFI adapter before the extension cord, and to test it at least once per event.

Generators are covered too. Under NEC 445.20, the 125 volt, 15 and 20 amp receptacles on portable generators of 15 kW or smaller must have GFCI protection, with an allowance for a listed GFCI cord set on generators built before 2015. Check the generator you own before assuming it complies.

OSHA adds: ground the generator as its manual says, keep it dry under a canopy in damp weather, and never connect it to a building's wiring without an electrician installed transfer switch.

Carbon monoxide is the generator hazard that kills. The US Consumer Product Safety Commission reports an average of about 100 deaths a year in the US from portable generator carbon monoxide, and says to run generators outside only, at least 20 feet from a home, with the exhaust pointed away from any building.

Apply the same distance to the party. JumpOrange places the generator at least 20 feet from the inflatable and all guest areas. OSHA adds 3 to 4 feet of clear space on every side and above it, as far as possible from gathering spaces.

One more reason that is specific to this business: the blower is an air intake. It pulls air from around it and pushes it into an enclosed space full of children. A generator exhausting toward the blower feeds its exhaust straight into the unit. Put the generator downwind of the blower, never beside it.

The rest follows from that. Rope or cone the generator off, route its cords away from foot traffic, keep fuel cans away from it, and never run it under a tent, in a garage or against a wall: open doors and windows may not stop carbon monoxide building up, per OSHA. Put the same rules in the customer's instructions, because a customer who drags the generator closer to the patio has undone all of it.

A generator add on turns a park with no power into a booking instead of a refusal. Published operator pricing runs from $50 to $150 per event, and outlet rules range from 50 to 100 feet.

How to set yours:

• Price by size, not one flat fee, as The Bouncy Store's two tiers do, and include a tank that covers the whole rental window.
• Set the outlet rule from your cord kit. If the truck carries 50 feet of 12 gauge per blower, your rule is 50 feet. A 100 foot rule needs 10 gauge.
• Ask for a dedicated circuit, not just an outlet, as Joy Bounce House does.
• Write the fallback down. No usable outlet on arrival means the generator fee applies. Put it in the agreement next to the power loss evacuation clause in your rental agreement and damage waiver.

Like the other add ons in how to price bounce house rentals, a generator rides on a delivery you are already making. It is also stock: promise the same generator to two parks on one Saturday and one of them deflates. List it as a rental item with the number you own, and checkout that only offers what is free for the party window stops offering it once every unit is out. Mark each inflatable as needing power and its rental page shows how many outlets it needs, while the pull sheet tells the crew which stops need cords.