This is one of the most commonly asked questions in this category, and there’s a genuinely useful, widely cited range to work from.
The commonly cited comfortable range
40% to 60% relative humidity is the band most often recommended for comfort and for a home’s fabric — below it, static and dry-air discomfort become more common; above it, condensation and mold risk rise, especially on cold surfaces like window frames and exterior walls.
How to actually check, rather than guess
A standalone thermo-hygrometer, placed away from any appliance’s direct airflow, gives an honest reading of the room overall rather than an appliance’s own sensor, which reads differently right next to its intake or output.
Numeric targets are easier to hold than named modes
Appliances with a numeric dial, like the COMFEE’ Aqua Dry 10’s 35–85% adjustable target, make it easier to hold a specific number than a named-mode control like Bosch’s Auto/Night/Laundry presets.
What we would not do
Suggest chasing an exact percentage down to the decimal. The comfortable range is genuinely a range — small day-to-day fluctuation within 40–60% isn’t something to correct constantly, and doing so mostly wastes energy and water for no real benefit.
Check your own manual before you follow anything here. Humidity ranges, wattages, voltage and current ratings differ from model to model, and the manufacturer's figures take precedence over anything written on this site. We report what makers and monitors publish — a target humidity percentage, a heater's tip-over and overheat protection, a plug or thermostat's maximum load rating — and we never turn a reading into a health verdict or a diagnosis. Questions about air quality and health are matters for a qualified professional and your national health authority, and this site points you to them rather than restating them. Where wiring, voltage or load ratings are involved, matching them exactly to your appliance is a safety matter, not a technicality.
The questions that keep coming up
Is a slightly different target fine for different rooms?
Yes — a kitchen or bathroom naturally runs more humid after use, and that's normal rather than a problem to chase down immediately. A bedroom or living room run continuously benefits more from holding a steady number.
Last reviewed 24 August 2026