Anyone who clicks through the Pyrotec kiln range will quickly come across the abbreviations H, HD, and HS – and wonder what they mean. The answer is actually quite simple once you know the key.
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Abbreviation H = 230 Volt, standard outlet
The "H" stands for the PtRh-Pt (Platinum-Rhodium/Platinum) thermocouple in combination with a 230V connection. In short: an oven with "H" runs on your normal Schuko outlet at home – no electrician, no heavy-duty power connection needed. This makes these models particularly attractive for beginners and hobby potters.
A typical example is the Pyrotec Profitherm PY 75 H: 77 liters firing chamber, up to 1,200 °C, runs on 230V. Or the Pyrotec Oven Studio ST 52 H with 52 liters and up to 1,200 °C – also Schuko-compatible.
The H in the name of the Pyrotec Profitherm PY 75 H signals that no heavy-duty power is required for operation.
Abbreviation HD = 400 Volt, heavy-duty power
"HD" stands for the same high-quality temperature sensor (PtRh-Pt), but with a 400V three-phase current connection (CEE). This means: more power, higher possible temperatures, and larger firing chambers – but you need a heavy-duty power connection. A typical example is the Studio ST 68 HD: same size as the Studio ST 68 H, but with 5.7 kW instead of 3.6 kW and up to 1,260 °C. The higher power input via three-phase current therefore allows for either more volume or higher temperatures than the corresponding H model.
The HD in the name of the Studio ST 68 HD signals that a heavy-duty power connection is required for operation.
Abbreviation HS = 400 Volt plus hinged lid
"HS" builds on "HD" – so it also features three-phase current and a PtRh-Pt thermocouple – supplemented by a decisive ergonomic advantage: the gas-spring-assisted hinged lid. Anyone who has ever lifted a heavy top-loader lid without assistance will immediately understand why this is a selling point. The lid swings open, holds its position, and at the same time protects the oven wall with a stable railing. A classic example is the Pyrotec Profitherm PY 138 HS: 138 liters, 1,320 °C, heavy-duty power – and precisely this comfortable hinged lid, which makes intensive work significantly more pleasant.
The HS in the name of the Pyrotec Profitherm PY 138 HS indicates that a heavy-duty power connection is required for operation, and the kiln features a gas-spring-assisted hinged lid.
The three Pyrotec series briefly explained
In addition to the letter abbreviations, Pyrotec also offers two fundamental product lines for you to choose from.
The Studio series (abbreviated ST) is primarily designed for earthenware and low-fire applications – Pyrotec itself recommends it mainly for glaze firings up to approximately 1,150 °C. The insulation is dimensioned accordingly, which keeps the price attractive. Technically, depending on the model, they can reach up to 1,200 °C (H models) or even 1,260 °C (HD models). If you primarily work with earthenware clays, you'll be well and affordably set here – if you regularly want to push the upper temperature limit, you should consider the Profitherm series.
The Profitherm series (abbreviated PY) is the more robust line, designed for higher temperatures. Profitherm series models can reach up to 1,320 °C, depending on the version, and are designed for more intensive use and high-fire applications. If you want to fire stoneware or porcelain, or simply want to remain flexible in the long term, this is the series to choose.
The Profitherm-HS series is the premium variant within the Profitherm line – technically identical, but supplemented by the gas-spring-assisted hinged lid, which significantly facilitates opening and closing the lid. Those who fire regularly and intensively will quickly appreciate this comfort. All HS models run on 400V heavy-duty power and can reach up to 1,320 °C – they are the first choice for anyone who wants top firing performance and ergonomic work at the same time.
Brief summary
| Abbreviation | Power Connection | Special Feature |
|---|---|---|
| H | 230V Schuko | For home, no heavy-duty power needed |
| HD | 400V CEE | More power, larger models possible |
| HS | 400V CEE | Like HD, plus hinged lid with gas springs |
If you are unsure which model suits your situation – just write to us. We at Formwerk Pottery Supplies Berlin are happy to help you find the right oven for your power connection, volume, and clay types.