The use of natural refrigerants as working fluids for HVAC and industrial heating requirements helps to achieve net zero CO2 emissions from these sectors. The transcritical CO2 heat pump system used for simultaneous heating and cooling applications is proven to be energy efficient. The dairy industry, food and beverage industry, hotels, and pharmaceutical industries require simultaneous heating and cooling. The dairy industry requires heating for pasteurization, high temperature (HT) treatment of pipelines, and clean-in-place (CIP). It requires cooling for milk chilling and storing it at 4 °C for long shelf life. Currently, NH3 refrigeration systems are used for cooling, and coal/oil/natural gas-fired boilers are used for heating. The theoretical evaluation of transcritical CO2 systems for simultaneous heating and cooling demands in the dairy industry is carried out. A simple transcritical CO2 system with and without an internal heat exchanger (IHX), a booster system, and an ejector system with and without an IHX are evaluated and compared in terms of performance and energy savings. Results indicate that the ejector system with an IHX performs better than the other systems. Energy savings of up to 32 % can be achieved by utilizing the ejector system with an IHX in the dairy industry instead of currently used systems. The experimental study on the ejector system with and without an IHX is also carried out to analyse the system performance, ejector efficiency and entrainment ratio. Results indicated that the COP is improved by 12 % when an IHX is applied at a gas cooler exit temperature of 42 °C.