Flow boiling of R245fa in a microgap with staggered circular cylindrical pin fins

•Investigation of flow boiling of R245fa refrigerant in a microgap populated with cylindrical circular cylindrical pin fins, for a wide range of mass flux and heat flux.•High speed visualization of flow regimes, including bubbly and foggy.•Comprehensive analysis of single-phase and two-phase average heat transfer coefficient, and comparison with an existing literature.•Ability to run two-phase flow experiments in a 200 μm microgap at pressures as high as 2 MPa.