A special range of furnaces is offered for 2100 °C in air. This temperature in air atmosphere is achieved with zirconia heating elements. These elements are capable of achieving element surface temperatures of 2200 °C in air. At room temperature zirconia elements do not conduct electricity. They must thus be preheated by secondary heating elements, which are an integral part of the furnace design. At elevated temperatures zirconia elements become practical electric conductors.

Typical areas for such furnaces are advanced research applications, high temperature reaction studies, sintering of advanced ceramics, melting and pouring of special glasses etc.

A specially designed power control allows accurate heating up and cooling down. Handling characteristics are operator friendly. Each zirconia element is controlled separately and the overall control is supervised by a microprocessor based programmable controller such as Eurotherm 2704. Elements are connected in such a way that failure of one will not cause a breakdown of the total power. Instead failure of one element leads to an automatic adjustment in the current to the remaining heating elements. The bottom loading furnace has sight ports located at front and back.

These furnaces ore offered as box, lift or tube furnaces, whereby the lift furnaces with four sided heating are generally preferred.