Complex sentence: In 1819 Strutt designed and built Derby Infirmary which he worked on with his freind Charles Sylvester who documented the new ways of heating hospitals and designing this with safer features such as self cleaning and air refreshing toilets.
Split into simpler sentences: In 1819 Strutt designed and built the Derby Infirmary which he worked on with his freind Charles Sylvester. Sylvester documented the new ways of heating hospitals that were included in the design and the healthier features such as self cleaning and air refreshing toilets.