One of the biggest obstacles to economic profitability of solar water heating systems is the investment cost. Retrofitting existing domestic hot water heaters when a new solar hot water system is installed can reduce both the installation and material costs. In this study, retrofitting existing water heaters for solar water heating systems in Swedish single-family houses was theoretically inves...

The primary energy consumption in residential buildings is determined by the envelope thermal characteristics, air change, outside climatic data, users’ behaviour and the adopted heating system and its control. The new Italian regulations strongly suggest the installation of centralized boilers in renovated buildings with more than four apartments. This work aims to investigate the differences ...

The UK faces a significant retrofit challenge, especially with its housing stock of old, hard-to-treat solid walled dwellings. In this work, we investigate the delivery of heated thermal comfort with a lower energy demand through four types of energy efficiency interventions: passive system, conversion device, method of service control, and level of service demanded. These are compared for thre...

The application of computerised optimisation techniques to the design of low and netzero energy buildings would provide building designers with a powerful design tool. This paper presents such a tool that is being developed that links TRNSYS energy simulation with an optimisation program based on genetic algorithms. This early design stage optimisation tool optimises 17 parameters including bui...

This study compares the performance of five electrical water heater models in the TRNSYS environment. The main capabilities, modeling assumptions and performance of the models are first assessed using an intermodel comparison. The main criteria for comparison are: domestic hot water supply temperature, power demand (time-dependent profile and overall energy use) and vertical temperature distrib...

According to the authors of this paper, mathematical point view allows us see what sometimes cannot be seen from designer’s view. The aim study was estimate influence most important parameters (volume heat storage tanks, daily consumption domestic hot water, optical efficiency, loss coefficient, and total area a solar collector) on thermal power output water (SDHW) system in European climatic c...

The objective of this work is to study the thermal behavior a solar heating system using an active layer, integrated in wall and supplied with hot water by parabolic trough collector (PTC). prototype includes PTC surface area 1.8m 2 , tank layer wall. A complete simulation model TRNSYS 16 software has been established. Simulation tests under climatic conditions city Errachidia located southeast...