Load calculation is an integral step in the selection and layout of mechanical equipment in buildings. Proper determination of heating and cooling loads ensures properly sized equipment, and subsequent efficient systems design. Accurate load calculation entails the inclusion of the effects of several processes. Among these is heat transfer through building envelopes. When combined with knowledge of infiltration and ventilation, heat transfer through building envelopes describes the thermal effect that the outdoor environment has on the indoor environment, and thus it is an important part in any load calculation.The main objective of the project is to provide the engineering and research community with critical building, heating, ventilation, and air-conditioning design parameters in the form of improved convection coefficients. The specific objectives are:Develop convection correlations for convective heat transfer at external walls in rooms with ceiling slot diffusers and floor supply registersDevelop guidelines for the application of the new convection correlations.Implement the new correlations in the ASHRAE Loads Toolkit.Integrate the correlations with existing material in the ASHRAE Handbook of Fundamentals.