Refinery hydrogen consumers (e.g., hydrocrackers and hydro-treaters) are normally operated at high pressure. The make-up hydrogen and recycle hydrogen compressors are commonly used to increase the pressure of the hydrogen streams. This requires compression work, which can be a major contributor to the operating cost. Therefore, apart from minimizing the flowrate of hydrogen utility, it is also important to reduce the compression work. This paper presents an improved nearest neighbors algorithm and introduces the pressure-impurity diagram for designing hydrogen networks with minimum compression work. Three literature case studies are solved to illustrate the proposed methodology. Validated using mathematical models, the results show that the hydrogen network can be designed to achieve the minimum hydrogen utility and compression work. The number of compressors can also be reduced. (C) 2018 Elsevier Ltd. All rights reserved.