Improving the Ashrae method for vertical geothermal borefield design

Fossa, Marco; Rolando, Davide

doi:10.1016/j.enbuild.2015.02.008

Cited by 32 publications

(23 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally the method does not perform well compared to other approaches (Section 2.3.8). Some of these issues of the ASHRAE method have been recently addressed by [33].…”

Section: Ashrae Handbook Methodsmentioning

confidence: 99%

Analysis and design methods for energy geostructures

Bourne–Webb

Burlon²,

Javed

et al. 2016

Renewable and Sustainable Energy Reviews

View full text Add to dashboard Cite

“…Generally the method does not perform well compared to other approaches (Section 2.3.8). Some of these issues of the ASHRAE method have been recently addressed by [33].…”

Section: Ashrae Handbook Methodsmentioning

confidence: 99%

Analysis and design methods for energy geostructures

Bourne–Webb

Burlon²,

Javed

et al. 2016

Renewable and Sustainable Energy Reviews

View full text Add to dashboard Cite

“…Previous research has shown that the Ashrae design tool can undersize or oversize the GHEs (Cullin et al, 2015;Fossa and Rolando, 2015). A preliminary study undertaken by the authors indicates that if the Ashrae design tool uncertainty is considered, it can potentially become one of the dominate uncertainty contributors and could significantly increase the length uncertainty.…”

Section: Design Length Uncertaintymentioning

confidence: 94%

Uncertainties in the design of ground heat exchangers

Mikhaylova

Johnston

Narsilio

2016

Environmental Geotechnics

View full text Add to dashboard Cite

Ground source heat pump (GSHP) systems have the potential to reduce the carbon dioxide footprint of buildings by providing them with sustainable heating and cooling energy from the ground at shallow depths. The financial viability of these systems depends on the adequate sizing of the ground heat exchangers (GHEs), which generally contribute the most to the overall capital costs of GSHP systems. Consideration of the uncertainties in the design of GHEs has the potential to improve GHE design by increasing the confidence in sizing GHEs for particular applications. This paper proposes a methodology for the estimation of the uncertainty in the design length of GHEs by considering the uncertainties involved with the selection of design parameters. By using the proposed methodology, a case study is presented where borehole GHEs are sized following a commonly applied design process recommended in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (Ashrae) handbook. The uncertainty in the resulting length of GHEs is estimated, and the sensitivity of this uncertainty to the uncertainties in individual design parameters is discussed. In addition, measures to reduce the length uncertainty are considered.

show abstract

“…As deeply discussed in Rolando 2015 andPriarone 2016, TRFs (g-functions) can be calculated according to different boundary conditions (i.e. at imposed heat rate, as in TecGeo and T p8, or temperature, as in EED) but in the Fo range pertaining to 10 year horizons they should not differ meaningfully.…”

Section: Resultsmentioning

confidence: 99%

“…The model, its accuracy and the comparison with literature similar methods are described in details in three papers by the Authors (Fossa and Rolando 2015, Fossa and Rolando 2016. Here in the following the main calculation steps of the T p8 approach are briefly presented.…”

Section: The Modified Ashrae Methods According To the Tp8 Modelmentioning

confidence: 99%

Investigation on the Effects of Different Time Resolutions in the Design and Simulation of Bhe Fields

Fossa¹,

Rolando²,

Priarone³

2017

Proceedings of the IGSHPA Technical/Research Conference and Expo 2017

Self Cite

View full text Add to dashboard Cite

The correct design of a field of Borehole Heat Exchangers (BHE) requires the knowledge of ground thermal properties, heat pump performance and building heating and cooling demand. The sequence of heat pulses from (to) the ground by the heat pump can be described according to different time steps, from hours to months and even years. The monthly time step approach is often the preferred design choice which involves recursive calculations (temporal superposition techniques) and the availability of precalculated temperature response factors (or g-functions) for given BHE field geometries. Such a complex computing task is usually performed thanks to commercial codes in order to fulfil a carrier fluid temperature at the end of a given time horizon, typically 10 or 25 years. In this paper the monthly design approach (EED code and TecGeo proprietary code) is compared with the three thermal pulse approach (modified ASHRAE Method Tp8) and it is demonstrated that for a representative series of case studies the three pulse calculation, easy to be performed at engineering level, is able to provide the correct BHE field overall length with 8% accuracy with respect to the reference monthly calculations.

show abstract

Improving the Ashrae method for vertical geothermal borefield design

Cited by 32 publications

References 10 publications

Analysis and design methods for energy geostructures

Analysis and design methods for energy geostructures

Uncertainties in the design of ground heat exchangers

Investigation on the Effects of Different Time Resolutions in the Design and Simulation of Bhe Fields

Contact Info

Product

Resources

About