Setup
Electrical, cost to run, and sizing. The numbers that decide whether it works in your garage.
This is the part of the purchase that goes wrong. Not the choice of unit — the discovery, after it arrives, that the heater needs a circuit the garage does not have, or that the chiller runs all night in August and the bill says so.
None of this requires owning the equipment. It requires the manufacturer’s rated kW, Ohm’s law, the National Electrical Code, and a willingness to do the arithmetic in public. So that is what these pages are: the circuit math, the running cost, and a calculator that shows its working instead of printing an answer and asking you to trust it.
The obvious disclaimer, stated once: we are not electricians and this is not an electrical design service. The arithmetic here is correct and the code references are cited, but your installation is governed by your local authority having jurisdiction and belongs to a licensed electrician. Use these pages to know what to ask for — and to know when a quote sounds wrong.
Everything in Setup
Electrical Requirements
What circuit your unit needs, and the code rule that decides it.
Sauna Electrical Requirements
Every common heater size, its amperage, and the breaker the 125% rule requires.
Cost to Run
What these units actually add to your power bill, computed from rated kW.
Cost to Run a Sauna
Monthly cost by heater size and session habit, at a rate you set yourself.
Cost to Run a Cold Plunge
Why a chiller costs less to run than people expect, and what actually drives the bill.
Tools
Calculators that show their work.
Sauna Heater Size Calculator
Room volume in, heater kW and required circuit out — with the arithmetic shown.