Abstract Heat recovery significantly and positively affects energy conservation and prevents global warming. A small flat heat pipe heat recovery device (SFHPHRD), which applies flat micro-heat pipe array (FMHPA) with welded, serrated and staggered fin on its surface, is designed as a core heat transfer component in the heat recovery systems of residential buildings. The air volume flow ratio between fresh air and exhaust air was maintained at a value of 1 in the experiment. Under simulated winter and summer conditions, the performance of SFHPHRD under varying indoor and outdoor air temperatures, air volume flows and rows of FMHPAs were separately investigated. Heat recovery efficiency, coefficient of performance (COP) and device volume were also analyzed. Important influencing factors, which affect the performance of SFHPHRD, were considered. Experimental data were combined actual data from buildings to analyze the energy conservation capacity and application of SFHPHRD. Results showed that efficient heat transfer of FMHPA with welded, serrated, and staggered fin and the independent components enables SFHPHRD to possess high heat recovery efficiency, high reliability, low resistance, and suitable volume. The maximum high heat recovery efficiency and COP can reach 78% and 91.9 under experimental conditions, respectively.