Net ZEB Case Studies - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 402

we estimated the magnitude of these energy losses. According to the
results of thermal simulations, if the real COP value for the GHP is 4.6,
1.4 MWh would be saved per year;
3. The elimination of the heat pump heat exchanger was examined to
reduce the complexity of the thermal plant. The simplification of the
plant could yield approximately 2300 kWh e of savings (around 25% of
the overall GHP consumption);
4. While the envelope thermal resistance is above standard, a simulation
was performed by adding 0.1 m of rock wool in the roof composition
(global U -value for the roof = 0.15 W/m 2 °C). A smaller U -value of the
roof would lead to overall electric energy savings of 200 kWh for the
whole year;
5. A 1.2 m 3 storage volume would allow a 1.1% energy savings. In this case,
the storage tank was well designed because the operating point (real
tank volume = 1 m 3 ) is very close to the point of lowest consumption;
6. PID temperature setpoints have been set to 21.5 °C for the heating
season and 25.5 °C for the cooling season. Moreover, around 600 kWh
(9.1% of heating consumption) can be saved by selecting a night setback
of 19 °C from 00:00 to 06:00;
7. The addition of blinds on south-facing windows is estimated to achieve
approximately 15 kWh of further savings during the cooling season (less
than 1% of the total electrical cooling consumption).