Choosing the appropriate generator for any particular steamroom is the most important factor in creating a personal steambath.  A properly sized steam generator should reach a comfortable temperature within 10-20 minutes.  A generator which is undersized may take substantially longer or may not even reach a comfortable temperature; one which is oversized will form an unusually hot area around the steamhead.

Each generator uses a resistance-type heating element to heat water and produce a given volume of steam, based on the kilowatt rating of the generator.  One kilowatt is equivalent to 3413 BTU's .  Therefore the heat output of the steam generators is fixed to the kilowatt rating.  Actual steambath temperature will depend on the construction of the steamroom and the generator selected to heat the room.


  1. Cubic foot of the steamroom
  2. Ceiling height--succeeding calculations are based on an average of 7 to 8 foot ceiling height.
  3. Building material physical properties.
  • Thermal conductivity
  • Insulation (R factor)
  • Mass (weight)
  1. Ambient room temperature--succeeding calculations are based on average temperature of 68 - 72.
  2. Wall temperature--exterior walls in cold climates will require additional heat.
  3. Actual line voltage supplied by local utility.
  4. Surface area--succeeding calculations are based on average rectangular shaped rooms.  The surface area per cubic foot for irregular shaped rooms may alter the calculations.

  1. CALCULATE CUBIC FOOT AREA OF THE ENCLOSURE.  Length x Width x Height = Cubic Feet.
  2. CONSIDER THE CONSTRUCTION MATERIALS USED IN THE STEAMROOM.   Using the overall cubic foot total as a base, increase or decrease by the following percentages upon the construction materials.  Refer to the following chart.

For each 10 linear feet of steam pipe exceeding 50 feet add 10 cubic feet to sizing calculation.

*Choose appropriate steam generator after calculating the adjusted steamroom
cubic foot, refer to the specifications for the proper steam generator model. 
a calculated cubic foot capacity falls between two models, always choose the higher-rated generator.

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