Steam generator size calculator
Sizes a steam generator the way it should be sized — on room volume and tile thermal mass, not floor area. Undersized generators are the most common specification error in this market and this is the arithmetic that prevents it.
Indicative. Softened feed and six-monthly descaling assumed — without them, expect a third of the service life.
How the calculation works
Volume first, then the tile
Room volume in cubic metres, multiplied by a factor for the finish: about 1.0 for standard ceramic, 1.3 for large-format porcelain, 1.8 to 2.0 for natural stone. The same room in marble can need a generator two sizes larger than in ceramic, and a quote that names a kW rating without naming the tile has not been calculated.
Why the finish matters this much
A steam generator has to heat everything in the room before the air holds saturation. Stone and thick porcelain hold an enormous amount of heat. Ceramic tile on a light substrate holds comparatively little. The generator is fighting thermal mass, not floor area.
External walls and glass
An external wall bleeds heat continuously, most noticeably in winter. Glass does the same. Both get a margin added, which is why a room with a large glass front and an outside wall can need a size up from an identical internal room.
Undersized is the common failure
If a room takes more than twenty minutes to become usable, or the steam visibly weakens partway through a session, or the unit never stops running, that is capacity rather than a fault. It cannot be serviced away.
Oversized is a fault too
An oversized generator short-cycles — surging to temperature, cutting out, cooling, surging again. It feels unpleasant in the room and it is hard on the element and contactor. Correct is better than large.
Questions we get asked most
How do I size a steam generator?
Room volume in cubic metres multiplied by a finish factor — around 1.0 for ceramic, 1.3 for large-format porcelain, 1.8 to 2.0 for natural stone — plus margins for external walls and glass. Floor area alone gives the wrong answer.
Why does tile choice change the generator size?
Because the generator has to heat the tile before the air holds saturation. Stone has far more thermal mass than ceramic, so the same room finished in marble can need a unit two sizes larger.
What supply does a steam generator need?
Up to 6kW is usually a 32A single phase circuit. Most domestic rooms land at 9 to 12kW, which generally means three phase. It also needs a water feed and a drain for the flush cycle.
Should I fit a water softener?
In the UAE, yes. It roughly doubles element life and costs a small fraction of a replacement generator. It reduces how often descaling is needed but does not remove the need for it.
Want the sizing in writing?
Send room dimensions and the tile finish on WhatsApp and we will confirm the rating — whether or not you buy the installation from us.
- COMPANY
- PK Technical Services Co.
Established 2024 - ADDRESS
- Madina Mall, Muhaisnah 4
Beirut Street, P.O. Box 211516
Dubai, United Arab Emirates - CALL OR WHATSAPP
- +971 50 123 4567