Ventilation & Electrical
Two areas where getting the details wrong is expensive to fix after the fact — and where the information you need isn't always volunteered upfront by the people selling you equipment.
Ventilation
Proper ventilation prevents CO buildup (for wood-burning heaters), maintains air quality, and ensures the sauna heats evenly. The positioning is counterintuitive to most people.
- Fresh air intake: Low on the wall near the heater,
6–8″above the floor - Exhaust: On the opposite wall from the heater,
8–10″above the floor — not near the ceiling
Low exhaust draws fresh air across the full room at body level rather than pulling the hottest air straight out from the ceiling. It ventilates where people actually sit, and expels cooler air rather than wasting the heat you've built up. Make the exhaust adjustable so you can close it during heat-up.
Electrical requirements
- Dedicated
240Vcircuit — never share with other loads - Amperage: determined by heater kW rating (kW × 4.17 for 240V gives required amps)
- All wiring inside the sauna: high-temperature rated (
105°Cminimum) - GFCI protection required by code
- Thermostat and timer controls: rated for sauna use or installed outside the sauna
- No standard electrical outlets inside the sauna
The neutral wire: My 240V circuit needed to include a neutral wire in addition to the two hot legs. This affects what cable you run and may affect your panel. Confirm the wiring configuration with the manufacturer before your electrician does the rough-in — it's far cheaper to get this right the first time.
The specialist requirement: The Xenio control unit requires an electrician with prior experience installing that specific unit. This is not disclosed at the point of sale and not every electrician has this experience. Ask before you hire, not after.
The electrician I was referred to by my sauna supplier quoted me 50% more than a second electrician I found independently. A referral is a starting point, not the only option. On a job that can run $1,000–2,500 depending on panel distance and local rates, that difference is significant.
Wire cost is an estimate only. Always use a licensed electrician. Get at least two quotes.