The article discusses the theoretical and practical aspects of the penetration into established market of the service sector. Lack of information about actual practical issues of market penetration for service company is to be considered as a problem of the paper. The goal of the paper is to present the procedural model of the market penetration actions for services sector. In order to create execution model scientific information on issues of market penetration is structured, synthesized, after its assessment according logic, feasibility and applicability of the results and the integrity of the business in terms of services. The flexible model is formed and suggested, which consists of 9 components: identification of some market leader(s), determination, which is the most attractive segment for serve, analysis of market leader’ service quality according 2 aspects, the search of the opportunities to improve the quality of service, analysis of the possibilities for potential price reductions, determination of new services purposefulness, identification of support desirability, and formulating of penetration strategy, which has to be clear according research results. There are reasoned content and consistency of the components of the proposed model in the article. The model has been tested on real business conditions; it helps for the service company to penetrate into the market.

Evacuated tube heat-pipe solar collector system with closed heat pipe has been experimentally investigated. Experiments have been fulfilled using the solar imitator whose energy irradiance on the surface of the solar collector at the constant ambient conditions is 800 W/m². Energy characteristics of the solar collector system with different flow -rates of the heat-transfer agent have been investigated using various flow-rate speeds of the heat-transfer agent. It has been stated that the increase of the flowrate of the heat-transfer agent in the system from 0.01 to 0.12 kg/s would minimize the average collector efficiency from 0.81 to 0.55. When the reduced flow-rate of the heat-transfer agent has been used in the system, the higher temperature of the hot water is reached in the storage tank and at the same time the temperature of the heat -transfer agent in the system is increased. Thus, more energy has been lost in the pipeline and hot water storage tank, but less energy is used for the circulation of the heat -transfer agent energy. Increasing the agent flow-rate speed in the system has reduced the heat losses in the pipeline, but more energy is used for the energy circulation of the heat-transfer agent. Therefore, the medium efficiency of the solar collector system has changed insignificantly (0.47 ± 0.01).