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The AIM Act is calling for 85% phase out by 2036 of hydrofluorocarbon (HFC) refrigerants due to their high global warming potential. This phase out makes it essential to separate, recycle and dispose of these HFC mixtures in an efficient and sustainable way. The separation of HFC refrigerant mixtures cannot be accomplished through conventional distillation due to their azeotropic nature. A promising pathway to face this challenge is introducing ionic liquids (ILs) as entrainers in extractive distillation due to their high chemical and thermal stability, negligible vapor pressure, designability, and high solubility. It is essential to understand the heat effects of these systems to properly size and design the equipment. However, there is a gap in literature for calorimetric experimental data for HFC/IL systems. This research focuses on calorimetric measurements of ionic liquid and pentafluoroethane (HFC-125, CF3CHF2) / difluoromethane (HFC-32, CH2F2) systems. The heat of absorption of these systems is measured with a Setaram Calvet calorimeter. The experimental data collected is then compared to calculated results from equation of state (EOS) modeling of solubility data. Isotherms of HFC-125 or HFC-32 with 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2C1im][Tf2N]) modelled with the Peng Robinson EOS and the Non-random two-liquid model (NRTL) are going to be primarily analyzed, as [C2C1im][Tf2N] is one of the most promising entrainers for the separation of HFC refrigerant mixtures.