Adaptive ventilation systems or demand controlled ventilation systems allow to adjust performance of a system, while maintaining acceptable or optimum parameters of comfort in serviced spaces and rooms, which allows to save energy resources according to actual demand of a serviced building. At stages of design and installation of variable volume ventilation systems a number of issues, which can increase their energy efficiency, are not taken into account. They are as follows: a) increase of transmission heat loss through walls of air ducts with decrease of airflow; b) adequacy of airflow adjustment at a fan in regard to load, decrease of negative effect of flow redistribution between all spaces in a case of a decrease of demand in one of spaces; c) efficient placement of primary load sensors in spaces; d) efficiency of placement of air distributors, limiting value of overcooling of air depending on layout of an air distribution system. The presented paper discusses those issues and gives recommendations for prevention of the mentioned negative effects.