Evaluation of Energy Savings for Water Loop Heat Pump Systems

Nowadays the most important features of an air-conditioning system are flexibility, independent working, low operating costs, all of these associated with very high cooling loads. At the same time, the main industrial countries want to employ low-impact systems with scanty emissions from combustion processes, especially in urban areas. The aim of this work is to verify whether and when it is possible to use “decentralized” systems instead of the traditional “centralized” ones getting an energy saving. In particular the Water Loop Heat Pump system (WLHP), in which water circulation balances, even completely, the heat released by the cooling plants with that absorbed by the heat pumps, may result particularly suitable. This kind of plant has to produce at the same time heating and cooling energy at the right place and in the right quantity with a high efficiency. First of all, the thermal loads of two types of buildings (a shopping centre and an office block) have been evaluated through the simulation of their behaviour in a whole year, with a hourly time-step, for different climate conditions, using the software Energy Plus. Then it has been verified the thermal load distribution on the different parts of the building at each time step. After this it became possible to compare the components behaviour of the Water Loop Heat Pump System and the traditional system during the whole year. In this way it has been evaluated the energy saving reached performing a WLHP system.