Air-circulating chamber ovens and dryers are characterized by excellent temperature uniformity. As a result, e.g. in the metal and plastics industries, or ceramics for calcination. Air-circulating chamber ovens and dryers are characterized by excellent temperature uniformity. As a result, e.g. in the metal and plastics industries, or ceramics for calcination. Air-circulating chamber ovens and dryers are characterized by excellent temperature uniformity. As a result, e.g. in the metal and plastics industries, or ceramics for calcination.