Bibliography: pages 51-54. / The microstructure of different types of industrially produced heating elements was examined and an x-ray diffraction method was devised to determine the relative amounts of α- and β-silicon carbide present in these materials. It was confirmed that the α- to β-silicon carbide transformation occurs during heat treatment, because of the influence of the nitrogen atmosphere in the furnace. The fabrication parameters important in the manufacture of heating elements were investigated. Porous sintered silicon carbide samples were made using different proportions of grit sizes and various firing schedules. Both resistivity and crushing strength were determined. It was found that the resistivity is dependent upon degree of sintering (indicated by crushing strength) as well as the packing density of the porous body.

This master thesis presents a new technological combination of two environmentally friendly sources of energy in order to provide DHW, and space heating. Solar energy is used for space heating, and DHW production using PV modules which supply direct current directly to electrical heating elements inside a water storage tank. On the other hand a GSHP system as another source of renewable energy provides heat in the water storage tank of the system in order to provide DHW and space heating. These two sources of renewable energy have been combined in this case-study in order to obtain a more efficient system, which will reduce the amount of electricity consumed by the GSHP system.The key aim of this study is to make simulations, and calculations of the amount ofelectrical energy that can be expected to be produced by a certain amount of PV modules that are already assembled on a house in Vantaa, southern Finland. This energy is then intended to be used as a complement to produce hot water in the heating system of the house beside the original GSHP system. Thus the amount of electrical energy purchased from the grid should be reduced and the compressor in the GSHP would need fewer starts which would reduce the heating cost of the GSHP system for space heating and providing hot water.The produced energy by the PV arrays in three different circuits will be charged directly to three electrical heating elements in the water storage tank of the existing system to satisfy the demand of the heating elements. The excess energy can be used to heat the water in the water storage tank to some extent which leads to a reduction of electricity consumption by the different components of the GSHP system.To increase the efficiency of the existing hybrid system, optimization of different PV configurations have been accomplished, and the results are compared. Optimization of the arrays in southern and western walls shows a DC power increase of 298 kWh/year compared with the existing PV configurations. Comparing the results from the optimization of the arrays on the western roof if the intention is to feed AC power to the components of the GSHP system shows a yearly AC power production of 1,646 kWh.This is with the consideration of no overproduction by the PV modules during the summer months. This means the optimized PV systems will be able to cover a larger part of summer demand compared with the existing system.

Content of this diploma thesis is to describe functioning of heat meters, billing of measured values and aplication of this knowledge on existing building. Apartment building have five storeys and a basement. Every storey have two apartments. Design of a heating system is divided into two separete variants. First variant consist of two gas condensing boilers as source of heat and second variant consist of heat transfer station.