Features: - With no exception, all the parts in direct contact with circulating air are built with stainless steel of adequate quality - Armored electrical resistances are fitted in heating sources, in independent receptacles easily acessible for inspection and maintance. They can also be heated by steam or natural gas. - Insulation and insulation covering: the whole structure is thermically insulated according to volume and range of temperature . Insulation coverings are normally manufactured with stainless steel sheet.