What size blower does your jumping castle need?

The blower is the heart of a jumping castle — it runs the whole time the castle is up. Fit one that’s too small and the walls stay soft and wobbly (unsafe and no fun); the right one keeps the castle firm and stable. Here’s how to choose.

Match the blower to the castle

Every castle is designed around a specific blower power. The maker specifies it — your job is to match it. As a rough guide:

The workhorse party castle (that 3.75 m × 4 m medium) almost always runs on a 1.1 kW (1.5 HP) blower — the most common size in South Africa.

kW to HP — quick conversion

Local blowers (like Chameleon’s REH range) are rated in kilowatts; older or imported ones in horsepower:

• 0.75 kW ≈ 1 HP
• 0.95 kW ≈ 1.3 HP
• 1.1 kW ≈ 1.5 HP
• 1.5 kW ≈ 2 HP
• 2.2 kW ≈ 3 HP

Buying used? Always check the blower

The blower is the single most common gap in a second-hand deal — old, mismatched, or “not included.” Before you pay, confirm it’s there, the right size, and healthy (no grinding or rattling bearings). A new replacement costs roughly R3 565 (0.75 kW) to R4 945 (2.2 kW), so factor that into any “bargain” without one. Full checklist in our used-buying guide.

Warning signs of a wrong or failing blower

• Walls sag or go soft when kids climb on — the blower is underpowered for the castle (or there’s a leak or blocked inlet).
• It never firms up properly — likely too small for that unit.
• Grinding or rattling — bearings on the way out; it’s dying.
• Trips the plug or smells hot — stop using it. Moisture in the motor is common after wet jobs; have it checked before it goes near children again.

Power and running

A blower runs continuously the entire time the castle is inflated, on a normal wall plug. Keep it dry and shielded from rain, route the lead where nobody trips over it, and never run it through a puddle. If you rent out castles, have a plan for power interruptions — a soft castle full of kids is exactly what you want to avoid.