Back to Search
Start Over
The employment of an earth-to-air heat exchanger as pre-treating unit of an air conditioning system for energy saving: A comparison among different worldwide climatic zones
- Source :
- Energy and Buildings
- Publication Year :
- 2020
-
Abstract
- Highlights • Earth-to-Air Heat eXchanger uses geothermal energy for air conditioning systems. • A 2D mathematical model of the EAHX is developed to obtain the system performance. • A case study office building is analysed for eight worldwide localities. • Air temperature variation along the EAHX and EAHX efficiency are calculated. • Reduction of thermal capacity of the coils inside air handling unit is evaluated.<br />A great fraction (20–40%) of primary energy is required for building air conditioning, so the use of renewable energy sources is increasing. The geothermal energy for Heating, Ventilating and Air Conditioning (HVAC) systems can be used considering an Earth-to-Air Heat eXchanger (EAHX). This work analyses the performance of an EAHX through a mathematical model (2D), as a function of diameter and length of the air ducts. The problem is solved with finite element method. A case study office building is analyzed. The air conditioning plant is characterized by fan-coil units and primary air; the EAHX is positioned upstream the Air Handling Unit (AHU) to pre-cool/pre-heat the air. The building is virtually placed initially in six Italian cities (different climatic zones according to Italian regulation DPR 412/93) and subsequently in eight worldwide cities according to Köppen climate classification. The following parameters are calculated: air temperature variation and thermal efficiency of the EAHX; the decreasing of cooling and heating capacity of the coils into the AHU. The best results refer to a duct length of 100 m for Ottawa (warm-summer humid continental climate, 65% capacity reduction), the worst ones for Rio de Janeiro (tropical wet and dry climate, maximum 24% reduction).
- Subjects :
- Thermal efficiency
Primary energy
Köppen climatic zones
020209 energy
0211 other engineering and technologies
02 engineering and technology
Article
HVAC system
021105 building & construction
Heat exchanger
HVAC
0202 electrical engineering, electronic engineering, information engineering
Duct (flow)
Electrical and Electronic Engineering
Italian climatic zones
Civil and Structural Engineering
business.industry
Mechanical Engineering
Geothermal energy
Thermal performances
Environmental engineering
Earth-to-Air Heat eXchanger
Building and Construction
Italian climatic zone
Renewable energy
Earth-to-Air Heat eXchangers
Air conditioning
Environmental science
business
Köppen climatic zone
HVAC systems
Subjects
Details
- ISSN :
- 03787788
- Volume :
- 229
- Database :
- OpenAIRE
- Journal :
- Energy and buildings
- Accession number :
- edsair.doi.dedup.....7bbc47d1ffdee58e43d4a8ecf0210115