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Calculation Machine

Sauna Ventilation Calculator

Fresh air exchange rate for a sauna room.

Reviewed by the Calculation Machine team · How we check our maths

Your values

ⓘ Live results

Results
Ventilation airflow
17.5 CFM
Room volume
210 cu ft
Intake vent size at 200 FPM
12.6 sq in

Quick answer

Saunas typically need about 4-6 complete air changes per hour to control humidity and refresh oxygen despite the heater running.

The formula

CFM = volume x ACH / 60

Worked example

Worked example

Using the values the calculator loads with.

Inputs

  • Sauna length6 ft
  • Sauna width5 ft
  • Ceiling height7 ft
  • Target air changes5 ACH

Result

  • Ventilation airflow17.5 CFM
  • Room volume210 cu ft
  • Intake vent size at 200 FPM12.6 sq in

How to use the Sauna Ventilation Calculator

  1. 1Measure the sauna's internal dimensions.
  2. 2Apply 4-6 air changes per hour for typical dry sauna use.
  3. 3Place the intake vent near the heater and exhaust low on the opposite wall.

Frequently asked questions

Why does a sauna need ventilation at all?

Without fresh air exchange, oxygen drops and residual humidity and odours build up between sessions.

Does this apply to infrared saunas?

Infrared cabins need far less airflow since they don't use hot rocks or steam.

About this calculator