Vertical drilling is recommended where space is at a premium. The plastic hoses are connected to the evaporator of the heat pump. The number of collectors depends on the soil conditions and the desired heating capacity. With this system, however, it is necessary to consider the type of soil. Loam, for example, performs better than dry sandy soil. A ground-water heat pump with vertical collectors has the great advantage that you can enjoy higher efficiency in winter. In addition, it needs little space and can be used just about anywhere. A possible disadvantage is the high investment cost for the drilling, but you will quickly recover the cost.