Improved model for the thermal performance calculation of non-planar window frames for building simulation programs

Gastines, Maureen Florence Laure Macé de; Villalba, Ayelén María; Pattini, Andrea Elvira

doi:10.1080/19401493.2016.1177117

Cited by 4 publications

(9 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The model used to calculate the frame conductance is the traditional one (Equation 1)with h i = 8 W/m 2 K and h o = 30 W/m 2 K. It is thus important to make sure that the THERM simulation was run with those film coefficients. Moreover, this conductance model is not suitable for frames with a U-factor higher than 6.2 W/m 2 K (de Gastines et al, 2016).…”

Section: Methodology For Evaluating the Algorithm Used In Energyplusmentioning

confidence: 99%

“…By transforming the frame geometry, the ratio between the boundary surface area and the projected frame area can be modified significantly. However, this ratio was found to be a key parameter in high-conductance frames thermal behaviour (de Gastines et al, 2016). On the other way, maintaining this ratio would imply the use of disproportioned frame projections, and falsify the envelope radiative exchanges calculation.…”

Section: Algorithm Weaknessesmentioning

confidence: 97%

“…The algorithm used by EnergyPlus to calculate heat transfer through frames is based on the traditional model of frame conductance (Equation (1)). De Gastines et al (2016) found that this model seems to be suitable for all frames with a thermal transmittance lower than 5 W/m 2 K, but is not for frames with a U-factor higher than 6.2 W/m 2 K. They proposed an alternative model that includes compactness factors to take into account the non-planar geometry of high-conductance frames (Equation (2)).…”

Section: Main Issues About Frame Thermal Modelling In Calculation Sofmentioning

confidence: 99%

See 2 more Smart Citations

Heat transfer through window frames in EnergyPlus: model evaluation and improvement

Gastines

Correa

Pattini

2018

Advances in Building Energy Research

Self Cite

View full text Add to dashboard Cite

Window frames can significantly affect the energy demand of buildings. Due to their complex non-planar geometry, twodimensional, time-consuming simulations are necessary to estimate with precision heat transfer through frames. However, in dynamic heat transfer calculation through computer-based building performance simulation tools, simplifications are made to reduce simulation time. In particular, EnergyPlus models window frames as rectangular profiles, and uses a one-dimensional heat transfer model. In order to evaluate whether this simplification is legitimate, thermal transmittance values were calculated for a selection of frames, on one hand through two-dimensional finite elements simulation, and on the other hand, through a spreadsheet that reproduces the steps of the algorithm currently used by EnergyPlus to calculate heat transfer through window frames. The comparison of both values showed relative errors higher than 20%, including for rectangular frames (without simplifying geometry). Aluminium frames without thermal break exhibited the highest absolute errors, up to 2.98 W/m 2 K. An alternative algorithm was proposed, which uses compactness factors for film coefficient calculation and reduced emissivities to take into account self-viewing surfaces. The proposed model improved the estimates, reducing the absolute error to less than 0.10 W/m 2 K in 52% of the occurrences, and to less than 0.47 W/ m 2 K for aluminium windows.

show abstract

Section: Methodology For Evaluating the Algorithm Used In Energyplusmentioning

confidence: 99%

Section: Algorithm Weaknessesmentioning

confidence: 97%

Section: Main Issues About Frame Thermal Modelling In Calculation Sofmentioning

confidence: 99%

See 1 more Smart Citation

Heat transfer through window frames in EnergyPlus: model evaluation and improvement

Gastines

Correa

Pattini

2018

Advances in Building Energy Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, the window set simulation is not efficiently applied despite its various advantages. In many studies, inconvenient user interfaces of window set simulation programs and difficulty in window set modeling are cited as examples of some obstacles [3,4]. In fact, the user should draw each edge of all window set members for window set modeling.…”

Section: Introductionmentioning

confidence: 99%

Automated Conversion of Building Information Modeling (BIM) Geometry Data for Window Thermal Performance Simulation

Kim¹,

Park²,

Choi

et al. 2019

Advances in Civil Engineering

View full text Add to dashboard Cite

A window set is defined as a window where the frame and the glass are combined and is used at the part that comes into contact with the air. As the performance evaluation of window sets has gained significance, the need for software that can simulate window set performance has also increased accordingly. However, the simulation of window sets is not carried out efficiently due to the difficulty in the window set modeling. Meanwhile, the design of building information modeling has recently proliferated so that the window set BIM library is distributed online. If such a window set BIM library is utilized in the window set simulation, it is expected that the productivity issue that occurs in the simulation process could be improved. Therefore, this study proposes a method to automatically convert the information required in the simulation of the window set heat transfer coefficient from the BIM. In order to achieve the purpose of this study, the following procedure is carried out. First, the framework for converting the information required in the simulation of the window set heat transfer coefficient from the BIM is suggested. Second, the method to extract and convert BIM data based on the suggested framework is proposed. Lastly, the BIM data conversion program is developed, and its performance is validated by applying the window set BIM case. The case study result showed that the information converted and entered from the window set data BIM conversion program coincided with the information entered in the window set BIM. It is expected that the result of this study will increase the productivity of window set simulations, which will lead to the increased use of certification through these simulations.

show abstract

“…To this day, the typical windows used in this country are aluminium-framed slider windows without thermal break combined with single glazing. Those windows have U-factors around 7 W/m 2 K (de Gastines, Villalba, & Pattini, 2016). The massive use of such poorly insulated windows constitutes a drastic technological backwardness, which is why the introduction of a window rating and labelling procedure for Argentina is crucial.…”

Section: Introductionmentioning

confidence: 99%

Window frame thermal performance simulation. Suitable methods according to climate and technology

Gastines

Correa

Pattini

2018

rdlc

Self Cite

View full text Add to dashboard Cite

Within the framework of window labelling system elaboration in Argentina, this article questions the suitability of replicating calculation procedures from other countries with different climatic and technological contexts. This paper analyzes the methodological differences between existing standards for calculating window frame U-factor. It focuses on the impact of the radiation model applied on the frame outside boundary. Simulations were performed on different window frames under three sets of environmental conditions, first using the NFRC blackbody radiation model at the outside boundary, then using the ISO 15099 detailed radiation model. The comparison of the resulting U-factors shows significant differences (up to 12.7%) between both models. The impact of outside boundary radiation model choice increases with the non-planarity of outside frame boundary and decreases at high wind speeds. According to these results, the ISO 15099 detailed radiation model should be used on both sides of the frame, in order to maximise the accuracy of non-planar frames thermal transmittance calculation under any environmental conditions.

show abstract

Improved model for the thermal performance calculation of non-planar window frames for building simulation programs

Cited by 4 publications

References 14 publications

Heat transfer through window frames in EnergyPlus: model evaluation and improvement

Heat transfer through window frames in EnergyPlus: model evaluation and improvement

Automated Conversion of Building Information Modeling (BIM) Geometry Data for Window Thermal Performance Simulation

Window frame thermal performance simulation. Suitable methods according to climate and technology

Contact Info

Product

Resources

About