# Proofing Room Steam Demand Calculator

[https://www.stilsan.com/en/tools/proofing-room-steam-calculator](https://www.stilsan.com/en/tools/proofing-room-steam-calculator)

Estimate the air-only lower-bound steam demand of a bakery proofing room from dimensions, initial and target temperature/RH, altitude and time; see an ST-1 or ST-2 preliminary candidate.

## How should this result be read?

The kg/h result applies only to the target time and loads you entered. The model is a capacity comparison, not a guarantee of uniform humidity, recipe performance or product outcome. Commission the empty and loaded room with measurements.

## Physical basis of the calculation

Relative humidity is not directly a mass. Temperature, RH and altitude-dependent pressure are first converted to humidity ratio W (kg water/kg dry air).

1. Dry-air mass is calculated from room volume and moist-air specific volume.

2. Initial-to-target humidity-ratio difference is multiplied by dry-air mass: mwater = mdry-air × (W₂ − W₁).

3. Water mass is divided by target time; entered air-change and process loads are added in kg/h.

## Our field anchor: a 62.5 m³ bakery proofing room

In a verified Stilsan field application, ST-1 was used in a room with about 25 m² floor area and 2.5 m height. One installation is not a universal sizing rule.

- ST-1: 10 kW electrical power and 12 kg/h company-guaranteed nominal steam output.

- The adjacent generator distributed steam low in this application to support the natural rise of warm humid air.

- A satisfactory visible steam condition was observed in roughly 2–10 minutes depending on site conditions; this is not a time guarantee.

- A humid Antalya start and a cold-dry Kars winter start are not equivalent; enter actual initial temperature and RH.

## What the calculation deliberately excludes

Dough recipe and temperature, rack mass, panel and door leakage, cold-surface condensation, air circulation, sensor position, control hysteresis and steam-line losses cannot honestly be reduced to one coefficient without measurements.

## Frequently asked questions

### Is ST-1 enough for a 25 m² proofing room?

We have real field experience with ST-1 in an approximately 25 m², 2.5 m-high bakery proofing room. It is not a universal guarantee without target temperature/RH, climate, product load, doors, insulation and line data.

### Can a proofing room become steamy in 2 minutes?

A warm, humid start can look satisfactory quickly; a cold, dry start can take longer. A 2–10 minute field observation is not a guaranteed target-RH time.

### Why distribute steam near the bottom?

The verified application used low-level distribution to support the natural rise of warm humid air. Outlet layout must still consider circulation, safety and condensate.

### Can a humidity sensor control the generator?

A suitable controller can call for steam while a separate heater or climate unit manages temperature. Electrical and control design must be verified for the project.

## Technical sources

Sources support the method; they are not third-party approval of Stilsan capacity or suitability for a particular room.

- [ASHRAE Handbook — Psychrometrics](https://handbook.ashrae.org/Handbooks/F25/SI/F25_Ch01/F25_Ch01_si.aspx)

- [PsychroLib — ASHRAE equations](https://psychrometrics.github.io/psychrolib/api_docs.html)

- [IAPWS-IF97 — water and steam](https://iapws.org/relguide/IF97-Rev.pdf)