scholarly journals Evaluating Patterns of Building Envelope Air Leakage with Infrared Thermography

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3545
Author(s):  
Milad Mahmoodzadeh ◽  
Voytek Gretka ◽  
Stephen Wong ◽  
Thomas Froese ◽  
Phalguni Mukhopadhyaya
Keyword(s):  
Infrared Thermography ◽  
Pressure Difference ◽  
Practical Implication ◽  
Cost Savings ◽  
Building Energy ◽  
Building Envelope ◽  
Air Leakage ◽  
Image Subtraction ◽  
Thermographic Image ◽  
Energy Codes

The next-generation performance-based building energy codes are focusing on minimizing building envelope air leakage. The quantification of air leakage in buildings is typically performed with a blower door test. However, this test does not provide information about the locations of air leakage. The aim of this study is to demonstrate a method involving qualitative and quantitative components that can be used to characterize locations of air leakage with infrared thermography. Since air leakage can have a significant impact on building energy consumption in cold climates, like in Canada, this approach can quickly inform where air barrier discontinuities occurred during construction or where to selectively target air sealing efforts in existing buildings. The observations from this study are presented, based on a thermographic image analysis during a depressurized blower door test at various pressures, in an attempt to quantify the relative rates of air leakage. The results from the investigation showed that infrared thermography (IRT) was able to discern locations and infer relative ratios of air leakage. The qualitative analysis showed that areas of air leakage are more evident under higher pressure difference. The quantitative approach showed that a minimum of 25 Pa pressure difference was required to detect the air leakage in the vicinity of the window frame, as the surface temperature decreased rapidly (almost 60% of the indoor surface/outdoor air temperature difference) at this pressure. A temperature index was defined to prioritize the areas of air leakage for retrofitting purposes. Furthermore, a thermal image subtraction method was used to determine the characteristics of the cracks based on thermal patterns. Finally, the practical implication of this study, for building developers, home inspectors, property mangers, and homeowners, is the early detection of air leakage for both existing and newly constructed buildings which could result in energy and cost savings.

Air infiltration through building envelopes: A review

2011 ◽  
Vol 35 (3) ◽  
pp. 267-302 ◽  
Author(s):  
Chadi Younes ◽  
Caesar Abi Shdid ◽  
Girma Bitsuamlak
Keyword(s):  
Indoor Air ◽  
Energy Demand ◽  
Building Energy ◽  
Building Envelope ◽  
Energy Costs ◽  
Air Leakage ◽  
Building Envelopes ◽  
Air Infiltration ◽  
Considerable Impact ◽  
Evaluation Techniques

Air leakage through the building envelope into the building interiors has a considerable impact on the energy loads and consequently energy demand and energy costs of buildings. This phenomenon known as infiltration happens through various openings and venues in the building envelope varying from large openings such as doors and windows to minute cracks and crevices. In addition to impacting building energy loads, infiltration impacts indoor air quality and can result in moisture accumulation problems in the building envelope. A generalized review of infiltration that includes evaluation techniques and models, quantification, and interaction with other heat transfer phenomena is presented in this article.

Using Vertical Green as Material for Complying Building Energy Code

2012 ◽  
Vol 622-623 ◽  
pp. 1035-1038 ◽  
Author(s):  
Kaweewat Sathien ◽  
Kuaanan Techato ◽  
Juntakan Taweekun
Keyword(s):  
Energy Saving ◽  
Construction Material ◽  
Building Energy ◽  
Building Envelope ◽  
Air Conditioner ◽  
Thermal Transfer ◽  
Plant Utilization ◽  
Energy Codes ◽  
Building Energy Codes

Plant utilization as a part of building envelope has never been introduced in view of the compliance to Building Energy Code or the successful building energy codes or even in view of energy for building labeling. This research tries to find out the approach to utilize the equivalent plant conductivity (ke) in order to make the plant as a construction material for the building envelope. The ke is plugged into the formula of the Overall Thermal Transfer Value to see the energy saving for air-condition from having vertical green. By testing on two rooms with air conditioner, one with vertical green and another is without vertical green, the room with vertical green reduced the Overall Thermal Transfer Value from 59.87 W/m2 to 49.39 W/m2.

scholarly journals The impact of window-to-wall ratio on energy intensity of existing office buildings in Ontario and Quebec

2021 ◽  
Author(s):  
Viktoriya Mykytyak
Keyword(s):  
Energy Intensity ◽  
Building Energy ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Geometry ◽  
Energy Codes ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship ◽  
New Buildings

Energy codes, such as SB-10, provide significant impact on the thermal performance of the building envelope. For design of new buildings, a window-to-wall ratio (WWR) of 40% is considered as a threshold in Ontario for using prescriptive solutions for thermal resistance of the enclosure. This study will demonstrate the relationship of the energy intensity of the existing office building to the WWR, through analysis of 15 office buildings located in Ontario and Quebec. Recent studies indicate that building geometry can influence the energy efficiency of the building; nevertheless, factors that impact energy intensity of existing buildings are not researched in full, and this study’s aim is to minimize the knowledge gap in this field of literature. The outcome of this research shows that WWR directly influences energy intensity of the building. Energy balance calculations and energy loads distribution showed that WWR impacts on average 15% of overall energy consumption

scholarly journals Indoor/Outdoor Relationships of Airborne Particles under Controlled Pressure Difference across the Building Envelope in Korean Multifamily Apartments

2018 ◽  
Vol 10 (11) ◽  
pp. 4074 ◽  
Author(s):  
Dong Choi ◽  
Dong Kang
Keyword(s):  
Pressure Difference ◽  
Urban Areas ◽  
Field Experiments ◽  
Fine Particles ◽  
Building Envelope ◽  
Test Method ◽  
Airborne Particles ◽  
Air Leakage ◽  
High Concentrations ◽  
Housing Units

This study investigates indoor/outdoor relationships of airborne particles under controlled pressure difference across the building envelope in Korean multifamily apartments. On-site field experiments on 14 apartment housing units located in urban areas in Korea are conducted to measure the indoor/outdoor ratios of number concentrations of size-resolved particles (0.3–0.5, 0.5–1.0, 1.0–3.0, 3.0–5.0, 5.0–10.0, >10.0 μm). To set identical pressure difference conditions across the envelope of each housing unit for better comparison of I/O ratio results, and to examine the effect of pressure difference on the I/O relations, indoor–outdoor pressure difference was controlled at 10, 30, and 50 Pa using a blower door depressurization procedure. Simultaneously, the air leakage characteristics of housing units are measured using the typical blower door pressurization-depressurization test method to correlate air leakage data and I/O ratios. As expected, moderately airtight housing units (ACH50 ≤ 4.4) show lower I/O ratios than average leaky housing units (ACH50 > 4.4); still, the averaged I/O ratios of finer sized particles (0.3–0.5, 0.5–1.0, and 1.0–3.0 μm) in the moderately airtight housing units were 0.75, 0.59, and 0.61 at an I-O pressure difference of 50 Pa, and 0.62, 0.51, and 0.49 at 10 Pa. The study indicates that indoor residents in moderately airtight Korean multifamily housing units with relatively small envelope area can still be exposed to high concentrations of outdoor originated fine particles.

scholarly journals Performance Assessment of Data-Driven and Physical-Based Models to Predict Building Energy Demand in Model Predictive Controls

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3125 ◽  
Author(s):  
Alice Mugnini ◽  
Gianluca Coccia ◽  
Fabio Polonara ◽  
Alessia Arteconi
Keyword(s):  
Energy Demand ◽  
Management Strategies ◽  
Cost Savings ◽  
Building Energy ◽  
Building Envelope ◽  
Training Data ◽  
Data Driven ◽  
Maximum Deviation ◽  
Set Point ◽  
Time Control

The implementation of model predictive controls (MPCs) in buildings represents an important opportunity to reduce energy consumption and to apply demand side management strategies. In order to be effective, the MPC should be provided with an accurate model that is able to forecast the actual building energy demand. To this aim, in this paper, a data-driven model realized with an artificial neural network is compared to a physical-based resistance–capacitance (RC) network in an operative MPC. The MPC was designed to minimize the total cost for the thermal demand requirements by unlocking the energy flexibility in the building envelope, on the basis of price signals. Although both models allow energy cost savings (about 16% compared to a standard set-point control), a deterioration in the prediction performance is observed when the models actually operate in the controller (the root mean square error, RMSE, for the air zone prediction is about 1 °C). However, a difference in the on-time control actions is noted when the two models are compared. With a maximum deviation of 0.5 °C from the indoor set-point temperature, the physical-based model shows better performance in following the system dynamics, while the value rises to 1.8 °C in presence of the data-driven model for the analyzed case study. This result is mainly related to difficulties in properly training data-driven models for applications involving energy flexibility exploitation.

Vacuum insulation panels (VIPS) in building envelope constructions: An overview

2016 ◽  
Vol 7 (2) ◽  
pp. 113-119 ◽  
Author(s):  
K. Song ◽  
P. Mukhopadhyaya
Keyword(s):  
Green Building ◽  
Building Energy ◽  
Building Envelope ◽  
Sustainable Building ◽  
Building Product ◽  
Vacuum Insulation ◽  
Vacuum Technology ◽  
Net Zero ◽  
The World ◽  
Energy Codes

Driven by updated building energy codes and green building initiatives across the world, vacuum insulation panel, also known as VIP, has become a desired insulation product for building envelope constructions. VIP has initial center-of-panel thermal conductivity of 0.004 W/mK or lower, and integration of VIP in building envelopes can reduce CO2 emissions and contribute towards ‘net-zero’ or ‘near-net-zero’ building constructions. Although VIPs have been applied in real-world constructions across the world, primarily in Asia, Europe and North America, it is still a novel building product under investigation. This overview paper is a summary of fundamentals, constituents, constructions and performances of VIPs. The paper shows there exists many advantages and challenges associated with the integration of VIPs in building envelope constructions. The speed at which VIPs will be integrated in building envelope construction in the coming years remains unclear; nevertheless, it is evident that vacuum technology is the promising way forward for sustainable building envelope constructions in the 21st century.

Energy code compliant house design for lowest lifecycle cost based on market-available technologies

2019 ◽  
Vol 46 (4) ◽  
pp. 308-321 ◽  
Author(s):  
Behnaz Hesaraki ◽  
YuXiang Chen ◽  
Regina Dias Ferreira ◽  
Mohamed Al-Hussein
Keyword(s):  
Cost Effective ◽  
Heating System ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Water Heater ◽  
Forced Air ◽  
House Design ◽  
Energy Codes ◽  
Code Compliance

Investigating code-compliant and market-available options for building envelope, domestic systems, and solar photovoltaic systems accounting for construction and operational cost, the near-lowest lifecycle cost (LCC) design compliant with building energy codes is identifiable following the methodology proposed in this study. A case study of a house design in Edmonton, Canada, is conducted to demonstrate the methodology; the 30-year LCC of options for code-compliance are calculated for three energy cost scenarios. The results indicate that the most cost-effective design may have a 16% to 30% lower LCC than other investigated designs. In terms of achieving a similar level of energy performance, a house that uses a heat recovery ventilator, forced-air gas-fired space heating system, tankless water heater, and features a less-insulated building envelope offers the lowest LCC. The results of this study suggest that LCC should be considered in the development of building energy regulations to include economic aspects while proposing energy standards.

scholarly journals The impact of window-to-wall ratio on energy intensity of existing office buildings in Ontario and Quebec

2021 ◽  
Author(s):  
Viktoriya Mykytyak
Keyword(s):  
Energy Intensity ◽  
Building Energy ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Geometry ◽  
Energy Codes ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship ◽  
New Buildings

Energy codes, such as SB-10, provide significant impact on the thermal performance of the building envelope. For design of new buildings, a window-to-wall ratio (WWR) of 40% is considered as a threshold in Ontario for using prescriptive solutions for thermal resistance of the enclosure. This study will demonstrate the relationship of the energy intensity of the existing office building to the WWR, through analysis of 15 office buildings located in Ontario and Quebec. Recent studies indicate that building geometry can influence the energy efficiency of the building; nevertheless, factors that impact energy intensity of existing buildings are not researched in full, and this study’s aim is to minimize the knowledge gap in this field of literature. The outcome of this research shows that WWR directly influences energy intensity of the building. Energy balance calculations and energy loads distribution showed that WWR impacts on average 15% of overall energy consumption

scholarly journals Application Method of a Simplified Heat and Moisture Transfer Model of Building Construction in Residential Buildings

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4180
Author(s):  
Joowook Kim ◽  
Michael Brandemuehl
Keyword(s):  
Latent Heat ◽  
Moisture Transfer ◽  
Residential Buildings ◽  
Building Energy ◽  
The United States ◽  
Building Envelope ◽  
Outdoor Environment ◽  
Transfer Model ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

Several building energy simulation programs have been developed to evaluate the indoor conditions and energy performance of buildings. As a fundamental component of heating, ventilating, and air conditioning loads, each building energy modeling tool calculates the heat and moisture exchange among the outdoor environment, building envelope, and indoor environments. This paper presents a simplified heat and moisture transfer model of the building envelope, and case studies for building performance obtained by different heat and moisture transfer models are conducted to investigate the contribution of the proposed steady-state moisture flux (SSMF) method. For the analysis, three representative humid locations in the United States are considered: Miami, Atlanta, and Chicago. The results show that the SSMF model effectively complements the latent heat transfer calculation in conduction transfer function (CTF) and effective moisture penetration depth (EMPD) models during the cooling season. In addition, it is found that the ceiling part of a building largely constitutes the latent heat generated by the SSMF model.

Sign in / Sign up

Export Citation Format

Share Document