Background/Objectives: Recent advances in IEEE 802.11ac based wireless networks have made them potential enough to be used for Voice over Wireless Local Area Networks (VoWLAN). The main requirement in the design of such network is to minimize the energy consumption to maximize the network lifetime of user equipment's. Methods/Statistical Analysis: For such energy conservation, the IEEE 802.11ac networks make use of power saving protocols, where the wireless radio is turned on and offperiodically. In this paper, a group based adaptive power saving mechanism is suggested that dynamically utilize the contention and transmission opportunity parameters of user equipment. Findings: The design of the power saving is unique as the grouping is based on the current power level of user equipment's, type of service, channel status and the number of services to a user equipment. Application/Improvements: Simulation results shows that proposed grouping technique provides an improvement of 46.25% and 47.29% in terms of energy consumption and delay, respectively compared the existing power saving protocol for delay sensitive and VoWLAN applications.