This paper presents research results to improve energy efficiency in one of the crude oil heating furnaces at the “Hermanos Díaz” refinery in Santiago de Cuba, Cuba. It analyzes the main process’s variables and disturbances, and the multivariate dynamic behavior of the F-101 furnace temperature is characterized to evaluate different control strategies. In addition, the design of a linear regulation control law was implemented as a way to solve the limitations of the existing control of the furnace, to control the plant for the first time with a multivariable approach, demonstrating superior performance by guaranteeing decoupling between the variables, decreasing the overruns by 6%, and increasing the response speed of the system by more than 5 min. The comparison with results obtained with other control strategies allowed us to determine the better performance of the furnace by increasing its energy efficiency, evidencing the economic and environmental impact and obtaining as benefits a better dynamic behavior by reducing fuel oil consumption by 5%, equivalent to 0.74 m³/day, which reduces the operating costs of the plant, the temperature of the gasses by 2%, emissions of CO₂ pollutant gas to the environment by between 3 and 5%, and increasing energy efficiency by 1.5%.