Validation of a Dynamic Simulation of a Classroom HVAC System by Comparison with a Real Model
Schools require thermal comfort in their classrooms , but some uncertainty arises as how their HVAC systems will actually provide it, especially given their high internal loads and mechanical ventilation diffusion. Thus, it is necessary to resort to computational fluid dynamics (CFD) for developing predictive models; nevertheless, the reliability of the simulation tool has to be verified, so the main objective of this work is to define and perform the validation process of a thermal dynamic simulation tool by comparison with a real room. A validation protocol has been detailed for dynamic simulation tools, in medium-sized spaces with high internal loads, by comparing with the measured air temperature values of an existing standard classroom, according to ISO 7726:2002. The chosen standard classroom for this comparison belongs to “Eça de Queirós” secondary school of Lisbon (Portugal). To that effect, 80 thermocouple sensors were used for the characterization of its indoor thermal behaviour. A mean bias error (MBE) of 0.21 °C was obtained, with a maximum standard deviation of 0.47 °C, which is under the maximum limit of ±0.5 °C established by this standard. The application of this methodology for validating the Design Builder software proves the reliability of this tool in such type of venues.
KeywordsCFD Software validation HVAC design Energy efficiency Classrooms
This work has been partially funded by the IV Plan Propio de Investigación de la Universidad de Sevilla. The authors wish to express their gratitude to the “Laboratório Nacional de Engenharia Civil” and the Public Entity “Parque Escolar” from Portugal.
- Campano MA (2015) Confort térmico and eficiencia energética en espacios con alta carga interna climatizados: Aplicación a espacios docentes no universitarios en Andalucía. PhD Dissertation, Universidad de Sevilla, SevillaGoogle Scholar
- Campano MA, Acosta I, Fernández-Agüera J, Sendra JJ (2015) Towards finding the optimal location of a ventilation inlet in a roof monitor skylight, using visual and thermal performance criteria, for dwellings in a Mediterranean climate. J Build Perform Simul 8(4):226–238. doi: 10.1080/19401493.2014.913683 CrossRefGoogle Scholar
- European Committee for Standarisation (1998) Ventilation for buildings. Design criteria for the indoor environments, CR 1752:1998. European Committee for Standarisation, BruxellesGoogle Scholar
- International Organization for Standardization (2002) Ergonomics of the Thermal Environment. Instruments for Measuring Physical Quantities, ISO 7726:2002. International Organization for Standardization, GenevaGoogle Scholar
- International Organization for Standardization (2004) Ergonomics of the thermal environment—Determination of metabolic rate, ISO 8996:2004. International Organization for Standardization, GenevaGoogle Scholar
- International Organization for Standardization (2005) Ergonomics of the Thermal Environment. Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria, ISO 7730:2005. International Organization for Standardization, GenevaGoogle Scholar
- Negrao COR (1995) Conflation of computational fluid dynamics and building thermal simulation. PhD Dissertation, University of Strathclyde, GlasgowGoogle Scholar
- School of Built and Natural Environment of Northumbria University. (2011) An inter-program analysis of computational dynamics based on PHOENICS and design builder. Available: http://www.designbuilder.co.uk/component/option,com_docman/task,doc_download/gid,39/Itemid,30/. Accessed 10 Mar 2016