Influence of Input Climatic Data on Simulations of Annual Energy Needs of a Building: EnergyPlus and WRF Modeling for a Case Study in Rome (Italy)

Abstract

The simulation of the energy consumptions in an hourly regime is necessary in order to perform calculations on residential buildings of particular relevance for volume or for architectural features. In such cases, the simplified methodology provided by the regulations may be inadequate, and the use of software like EnergyPlus is needed. To obtain reliable results, usually, significant time is spent on the meticulous insertion of the geometrical inputs of the building, together with the properties of the envelope materials and systems. Less attention is paid to the climate database. The databases available on the EnergyPlus website refer to airports located in rural areas near major cities. If the building to be simulated is located in a metropolitan area, it may be affected by the local heat island, and the database used as input to the software should take this phenomenon into account. To this end, it is useful to use a meteorological model such as the Weather Research and Forecasting (WRF) model to construct an appropriate input climate file. A case study based on a building located in the city center of Rome (Italy) shows that, if the climatic forcing linked to the heat island is not considered, the estimated consumption due to the cooling is underestimated by 35–50%. In particular, the analysis and the seasonal comparison between the energy needs of the building simulated by EnergyPlus, with the climatic inputs related to two airports in the rural area of Rome and with the inputs provided by the WRF model related to the center of Rome, show discrepancies of about (i) WRF vs. Fiumicino (FCO): Δ = −3.48% for heating, Δ = 49.25% for cooling; (ii) WRF vs. Ciampino (CIA): Δ = −7.38% for heating, Δ = +35.52% for cooling.

Ten questions on urban building energy modeling

“…For instance, the effects of UHI, a term raised by Manley in 1958(Manley, 1958, might lead to changes to building energy demand (e.g., a decrease in heating but an increase in cooling) depending on the city (Davies, Steadman and Oreszczyn, 2008), type of building (van Hooff et al, 2016), or meteorological conditions (Xu et al, 2012), which yield a wide range of impacts on energy consumption and occupant health. A recent modeling study based on a building located in the center of Rome, Italy, indicated that the energy consumption of cooling would be underestimated by 35%-50% if the climatic effect of the heat island is not considered (Ciancio et al, 2018). More studies related to the urban microclimate and the UHI effect and its mitigation technology solutions can be tracked down in a recent special issue of Urban Science (Yang and Santamouris, 2018).…”

“…Aligned with the stakeholders' interest, potential applications of UBEM are reviewed in three domains as summarized in Table 3. Qomi et al, 2016;Hong, Chen, Piette, et al, 2016) Demand energy auditing and forecasting Demand flexibility (Pezzulli et al, 2006;Fu et al, 2009;Delmastro et al, 2017;Wang et al, 2018) Urban resiliency (Gros, Bozonnet and Inard, 2014;Link, Pillich and Klein, 2014;Caro-Martínez and Sendra, 2018;Frayssinet et al, 2018;Oregi et al, 2018) Existing urban buildings retrofiting Energy savings; GHG emissions reduction; Cost effectiveness (Ward and Choudhary, 2014;Lee et al, 2015;McArthur and Jofeh, 2016;Monteiro et al, 2018;Nagpal and Reinhart, 2018) Urban energy planning Energy efficiency (Chow, Chan and Song, 2004;Fu et al, 2009;Lin et al, 2010;Koch, 2016;Delmastro et al, 2017) Urban resiliency under climate (Pisello et al, 2015;Martin et al, 2017; change effects Ciancio et al, 2018;Katal, Mortezazadeh and Wang, 2019) First of all, the formulation of energy policies for urban building stock frequently requires the evaluation of the overall building energy performance of the urban districts (Tardioli et al, 2018)…”

Passive Ambient Comfort and Correlation of Strategies and Vernacular Devices for Habitat Design in Arid Zones: The Case of Biskra, Algeria

“…These criteria are based on the adoption of appropriate parameters for building orientation, shape, envelope insulation systems, passive heating and cooling mechanisms, shading and glazing. Consequently, the energy performance of a residential habitat depends on its design and location [19,20]. This conception strongly depends on a building's immediate environment and its built form-in other words, the position of the sun at different times of the day and time of year and the geometry of a built context [21][22][23].…”

“…The analysis of the energy needs of a building (due to heating and cooling) is the basis for the optimization processes of consumption in the residential building sector [20].…”

“…The boundary conditions data [52] used in the energy analysis are summarized in Table 3. A Weather Research and Forecasting (WRF) model [20] was used to determine the temperature given in Table 3 (heating and cooling set-points).…”