Ground-source heat pump application for greenhouse heating with approach of degree-hours method

In this study, GSHP systems have been investigated for supplying heat requirements of a greenhouse which will be established in Kütahya, according to annual outside temperature data of Turkish State Meteorological Service during the last 15 years in terms of Degree-Hours Method. It has been found out that Degree-Hours Method has more precise results compared to approach of Degree-Days in "TS 825 Thermal Insulation Rules In Buildings". Degree-Hours Method gives information about the hours of temperatures for long-term periods. Thus, it is possible to estimate the annual energy requirements of structures for both heating and cooling seasons. As a result, bivalent heating operation type has decreased the start-up expenses 40% compared to monovalent system and the polyethylene cover metarial provides approximately 35% heat loss saving in comparison of single-glazing. In addition to this, advantages and disadvantages of various cover materials for greenhouses have been taken into account and the effects of such metarials on farm yields have been investigated. The results have shown that GSHP is more affordable rather than the other heating systems. Finally, annual heat loss of greenhouses have been calculated for some cities of Turkey that enables to estimate energy requirements during the year.