Abstract
Ground heat is a renewable resource that is readily available for buildings in cool climates, but its relatively low temperature requires the use of a heat pump to extract it for heating. We developed a system that uses low temperature ground heat directly in a building wall to reduce transmission heat losses. The Active Low Exergy Geothermal Insulation Systems (ALEGIS) minimizes exergy demand and maximizes the use of renewable geothermal heat from the ground. A fluid is pumped into a small pipe network in an external layer of a wall construction that is linked to a ground heat source. This decouples the building from the outside temperature, therefore eliminating large peak demands and reducing the primary energy demand. Our steady-state analysis shows that at a design temperature of -10 °C the 6 cm thick active insulation system has equivalent performance to 11 cm of passive insulation. Our comparison of heating performance of a building with our active insulation system versus a building with static insulation of the same thickness shows a 15% reduction in annual electricity demand, and thus exergy input. We present an overview of the operation and analysis of our low exergy concept and its modeled performance.
Original language | English (US) |
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Pages (from-to) | 3149-3166 |
Number of pages | 18 |
Journal | Energies |
Volume | 5 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2012 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Control and Optimization
- Energy (miscellaneous)
- Engineering (miscellaneous)
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering
- Building and Construction
- Fuel Technology
- Renewable Energy, Sustainability and the Environment
Keywords
- Buildings
- Exergy
- Geothermal
- Ground heat
- Heat pumps
- Insulation