Nowadays for Ukraine the problem with saving energy resources is especially relevant in a conditions of market economy, where the main energy carriers, such as oil and gas, are limited. That’s why in the last decade with the aim of saving energy resources the fundamental researches of activity of different branches, manufactures and technologies from positions of exergy methodology are held abroad. Today cost estimates can’t be the only measure of effectiveness of energy equipment which recycles energy resources. Exergy is physical, not economical criterion and determines independence of this parameter from price fluctuations. The application of exergy allows to give objective assessment of energy resources of any type as it is the only measure of working capacity, applicability of energy resources. There are many examples of successful application of exergy methodology by technical and economical optimization in industry, especially in energy intensive branches. The minimum should be determined by exergy losses per unit of provided heat, not by financial costs. The analysis of exergy effectiveness of implemented central straight flow air conditioning system (ACS) for operating cleanrooms which was obtained on its innovative mathematical research model depending on different factors that have influence on its work was presented in this article, and ways of energy saving for this ACS was proposed. It was found that the biggest impact on exergy output-input ratio of its air conditioning system have the temperature difference between inside and supplied air in a room, temperature of inside air which is depends on temperature of outside air, and coefficient of transformation EER of chosen refrigeration machine of air conditioning system. It was shown that with the aim of energy saving the implemented air conditioning system should be preferably used at a higher temperature difference between inside and supplied air, for example, = 9,0°С (at any temperature of inside air) and at higher coefficient of transformation, for example = 4,0, which gives the opportunity to get the highest exergy output-input ratio , which means to get the most energy saving variant of exploitation of implemented air conditioning system.