ᐅ Basic Questions About Types of Heat Pumps for New Construction

We are planning to build a house in Carinthia, Austria, with a gross floor area of about 180m² (approximately 1,940 sq ft) evenly distributed over two floors, and a heating demand of around 25 kWh/m² per year. The plot is 890m² (about 9,580 sq ft) and quite flat.

As a heat source, we plan to use a heat pump combined with underfloor heating and a centralized ventilation system (the ventilation unit is from Zewotherm, which is actually an Austrian product, and I work for the manufacturer in Austria).

For the heat pump, we are initially considering Ochsner or Neura. Possible options include a ground collector (either brine-based or direct expansion) or deep drilling. A ground collector would be more economical and feasible since the plot is large enough.

However, one issue is that there is percolating water approximately 1 meter (3.3 feet) below the surface, roughly at the frost line. The soil is otherwise sandy.

Now the question is: is the percolating water more of a benefit or a disadvantage regarding a ground collector system? Using groundwater for a groundwater heat pump is unfortunately not an option here.

We inherited the plot from my mother-in-law, and the existing house is beyond repair (built in 1947 with very basic methods).