PV Powered Groundsource
System:
- 260m2 Rehau PeX underfloor system with 150mm centers in living areas and 200mm centres in bedrooms – Single Zone.
- Fully under & edge insulated slab, way over H3 of the building code.
- 180L Superheat Buffer Tank.
- 4x40mm ground loops @ 200m each buried at 1.8m depth – filled with water & 30% food grade mono-propylene Glycol.
- Sirac 12kWh Water to Water Heatpump.
- 8kWh Solar PV system.
- Heatmiser NeoStat Control system controlling Slab temp.
Operation:
- Heatpump has a Maximum input power rating of 3.8kWh.
- The system utilizes power from the PV Array during daylight hours. The energy is stored in the Slab as thermal energy instead of electrical
energy. Slab is powered up to 29°C, at 5pm the system switches off. Any excess electricity is sold back to the Grid.
- The slab is designed to hold its heat through the night – on testing it was still 22°C the following morning (August).
- Exceptionally low running cost.
Note:
- This was intended to run as a single control zone and utilize the entire Slab as a thermal battery, Air temperature is
somewhat ignored, instead we measure the Slab temperature to a 1/10th of a degree. This system will get more efficient as
time passes as it will take the Slab approximately 3 years to fully cure.
