In this paper, we present a standard power-hardware-in-the-loop testing platform that can real-time simulate detailed air-source heat pump dynamics based on well-established modeling knowledge. Distributed air-source heat pumps can be potentially used for fast frequency response. However, using air-source heat pumps for rapid modulation cannot be based on the current assumptions of linear speed-power transient characteristic, which was developed for low-speed temperature control applications. Customized setups with experimental validation options are needed to design the new fast frequency response compatible heat pump controllers. Most power system laboratories struggle in building a customized air-source heat pump, which hinders the research progress. The proposed platform is relatively universal, can fit to different heat pumps with minor modifications and be implemented on standard PHIL emulators in power system laboratories. Emulation results, real-time implementation details and model complexity metrics are presented, to assist transference of the setup to other laboratoriesÂ