Telecommunication base station (TBS) has high indoor IT heat dissipation rate, and cooling load exists almost all year around. Energy consumption of air-conditioning system is 30-50% of the TBS entire energy. Envelope and heat pipe assisted air-conditioning system performances are investigated using annual hourly simulation software. In cold city Harbin, high insulation envelope is recommended to avoid heating requirement in winter; and in warm city Guangzhou, low insulation envelope is recommended to reduce the annual cooling load. Shading and roof ventilation have little impact on the reduction of cooling load. Simplified analysis method based on daily average steady values is proposed, which can reveal the main performance influencing factors and clearly direct the main approach in energy saving. The simplified method can accord well with numerical results and tested results available in literature. Contribution of each heat source can be clearly gained and analyzed, solar radiation does not possess large effect in TBS. Ideal thermal resistance with no heating or cooling requirement is then derived, envelope can be easily optimized and contribution of such kind of outdoor cooling source method using heat pipe can be easily obtained. (C) 2010 Elsevier B.V. All rights reserved.