Harvia Virta Pro: commercial-grade Finnish workhorse.

The Virta Pro is what shows up when a hotel sauna, a public bath, or a serious home installer needs a heater that nobody has to think about for ten years. It is not pretty. It is also not trying to be.

What's in the box

A floor-standing stainless-steel cabinet, 10.5 / 12.5 / 15 / 18 kW options, 90 kg stone capacity, integrated steamer slot on the Pro+ variant. Compatible with Harvia's Xenio or Griffin control units.

Sizing it to your room

• 10.5 kW → 9–18 m³
• 12.5 kW → 12–22 m³
• 15 kW → 14–26 m³
• 18 kW → 18–30 m³

These ranges assume well-insulated rooms. For commercial or high-throughput saunas, size up — the heater spends most of its day at idle holding setpoint, and a too-small unit will struggle on a back-to-back sessions schedule.

Install requirements

• 3-phase 400 V mandatory across the entire range.
• Floor-standing — the 90 kg stone load plus heater frame is over 130 kg total, well past wall-mount territory.
• Requires Harvia control unit (Xenio for home, Griffin for commercial/timer-locked installs). The Pro+ steamer variant needs a water line.
• Service clearance ~150 mm sides, 1200 mm front for the door and stone access.

Verdict

For a 6-person home sauna, the Virta Pro is overkill — a Cilindro or smaller Virta does the same job at half the footprint. For an 8+ person room, a daily-use commercial setting, or a build where the bather count is unpredictable, the Pro is the answer you stop second-guessing.