The thermal energy demand to heat houses and stables of agricultural farms and to supply them with warm water could be partly reduced by insulation and is conventionally compensated by the combustion of oil. Typical agricultural alternatives are the combustion of wood and straw and the heat recovery from stables using heat exchangers and heat pumps.
These heating systems could be used separately or in combination and because of that they must be examined simultaneously. To prevent oversized heating systems or an insufficient use of these systems and as a result of this unnecessary costs, the examination of economy of these systems must be based on a spatial and temporal distribution of the heat demand. For this comprehensive calculations a computer program was developed, which is able consider the individual conditions of any farm.
This program varies the heat transmission and because of that the heat demand, and examines at alternatively economic conditions all combinations of heating systems, which are able to compensate heat losses at any time. The most economic heating system has the lowest total costs per year. An analysis. considering special offers of the mentioned heating systems, turned out that all systems could only be used economically by additional insulation. The use of the heat pump resulted in the highest total costs per year in all cases. An universal economic ordering of rank couldn't be given, because the costs of investment as well as the heat demand changed a lot. By using the program the most economic solution to compensate the heat demand could be picked out for any farm.
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