This book provides the basic knowledge and guides for the construction and operation of a small-scale, family-size biogas unit. The first chapter discusses the benefits of biogas production and the Chinese biogas model. The second chapter shows the components, design formulas, and sizing units of the biogas model. Chapter 3 describes actual construction methods. The last chapter outlines the operation and maintenance of the biogas digester. Appendices include: (1) an introduction to the process; (2) design and plan; (3) feasibility study; (4) estimated costs of materials; (5) daily slurry quantities; (6) manure and urine estimates; (7) gas production estimates; (8) masonry; (9) manual tools for construction; (10) formulas and conversions; (11) biogas lamp construction; (12) background for biogas production in the People's Republic of China; and (13) vocabulary. Lists 16 references. (YP)