Humidifier Sizing Calculator
Moisture load (kg/h) to hold an indoor RH target against ventilation in winter.
Ventilation dominates winter humidification โ every L/s of cold outdoor air needs continuous water. Watch window condensation before chasing 50% RH.
Formula
Humidifier Sizing Calculator is a free humidifier size for HVAC designers, technicians and energy auditors โ instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Humidifier Sizing Calculator
Moisture load (kg/h) to hold an indoor RH target against ventilation in winter. The calculation implements แน_w = ฯยทVฬยท(w_in โ w_out); steam power โ 0.75 kW per kg/h (ASHRAE Handbook โ Systems, humidifiers chapter). Ventilation dominates winter humidification โ every L/s of cold outdoor air needs continuous water. Watch window condensation before chasing 50% RH.
How to use Humidifier Sizing Calculator
- 1Enter Ventilation airflow in L/s.
- 2Enter Target indoor humidity ratio in g/kg (22 ยฐC/45%RH โ 7.4 g/kg).
- 3Enter Outdoor humidity ratio in g/kg (0 ยฐC/80%RH โ 3; โ10 ยฐC โ 1.3).
- 4Read Humidification load, If isothermal (steam): power instantly โ no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Humidifier Sizing Calculator?
- โImplements the standard formula โ แน_w = ฯยทVฬยท(w_in โ w_out); steam power โ 0.75 kW per kg/h
- โReference cited on-page: ASHRAE Handbook โ Systems, humidifiers chapter
- โOne-click SI โ Imperial toggle โ values convert in place, physics stays in SI
- โRuns entirely in your browser โ nothing uploaded, free forever
Frequently asked questions
What formula does the Humidifier Sizing Calculator use?+
It computes แน_w = ฯยทVฬยท(w_in โ w_out); steam power โ 0.75 kW per kg/h, per ASHRAE Handbook โ Systems, humidifiers chapter. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
Ventilation dominates winter humidification โ every L/s of cold outdoor air needs continuous water. Watch window condensation before chasing 50% RH.
Is this based on ASHRAE methods?+
The calculations follow the standard ASHRAE/ISHRAE formulations cited under the result, simplified where industry practice does the same. For permit-grade design, confirm with the full code procedure.
Is the Humidifier Sizing Calculator free to use?+
Yes โ completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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