The efficiency of cooling the intake air of the engine room for cogeneration gas engines of the trigeneration plant with selfcontained power supply has been analyzed. There is considered one- and two-stage air cooling using a coolant from an absorption lithium-bromide chiller and a coolant with lower temperature obtained in a combined two-stage heat recovery chiller. As a result of the analysis, the methods of heat humidity treatment of the engine room intake air, that provide its deep cooling, are suggested. The influence of the scavenge air temperature on the fuel efficiency of a cogeneration gas engine is analyzed. There are calculated the reductions in specific and daily fuel consumption using the system of two-stage zonal and supply air cooling in comparison to a standard system of technical air conditioning in an engine room. Feasibility studies and payback period of the suggested technical solutions are also represented in the article.