geoAir - Soil Regeneration Through Exhaust - and Outdoor Air

The GeoAir combines a ground-source Heat Pump with a ventilation system, allowing for regeneration through exhaust and outdoor air.
This reduces the net extraction power by up to 60 %, enabling a significantly reduced geothermal heat source, resulting in substantial cost reductions.

Description

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Speaker

south_east

When & Where

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Thu, 10.10.2024, 10:00 – 10:20

place

Hall 4A / 4A-419

Details

Format: Lecture

Language: English

Description

The central innovation lies in utilizing the exhaust air for heating the brine via a heat exchanger, enabling year-round regeneration of the ground. This leads to significant cost savings for groundworks and minimizes space requirements, particularly advantageous in areas with rising property prices.

When the brine temperature is colder than the outside air temperature, the outside air regenerates the ground via a heat exchanger. This is often the case, especially in summer. Additionally, the drawn outside air is slightly cooled before ventilation heat recovery, providing additional cooling to the supply air and ensuring comfort even at high outdoor temperatures.

Integrating preheating of outside air via brine also prevents icing on the cross-flow heat exchanger of residential ventilation. This technology ensures reliable operation regardless of climatic conditions and without the need for electric heating elements for de-icing, thereby increasing the efficiency of the ventilation system.

Preheating the supply air through heating system return flow via a heat exchanger is an innovative measure to guarantee maximum comfort of residential ventilation even in winter.

Year-round source regeneration reduces net ground withdrawal. Consequently, the geothermal source can be designed smaller, enabling cost-effective and space-saving use of geothermal heat pumps. By reducing net ground withdrawal with GeoAir 3, probe lengths can be shortened by up to 35 %, or cheaper technologies like trench collectors or geothermal baskets can be used in constrained spaces. Implementing GeoAir in a construction project in Vorarlberg, consisting of three buildings (2500 m2 net floor area), led to significant cost savings. Initially, €140,000 was budgeted for the entire groundworks with a 1550 m borehole. By using GeoAir, we were able to reduce net withdrawal by -50 % and switch to a combination of boreholes and trench collectors. This approach resulted in savings of over €61,000, equivalent to a reduction of -44 %.