Net ZEB Case Studies - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 399

Fig. 7.40 Breakdown of how the cooling load was supplied
Fig. 7.41 Breakdown of how the heating load was supplied
Further analysis has been made on the radiant floor modeling. In TRNSYS,
there are two models for hydronic systems - quasi-analytical formulation
(Active Layer) and a two-dimensional finite difference model (Type 705).
Thequasi-analyticalformulationwasdevelopedtocalculatetheinternaland
surface temperatures of the radiant systems based on room air and inlet
water temperature and flow rate. Three-dimensional heat transfer is taken
into account. Radiant floors have been modeled as an active layer of the
floor (Type 56). However, TRNSYS offers also other solutions - Type 705
and others. Type 705 has more inputs and a higher degree of customization
of the geometry of the pipes, while the chosen active layer model of Type
56 calculates thermal parameters from the data introduced in the layer
definition window. A comparison between the two options described was
performedonasinglethermalzonewithaninlettemperaturefixedat28°C.