Influence of Air-tightness on Heat Energy Performance in Post and Beam Building with Exposed Wood Frame

The main goal of this study was to review current studies on the state of the art of wood constructions with a particular focus on energy efficiency, which could serve as a valuable source of information for both industry and scholars. This review begins with an overview of the role of materials in wood buildings to improve energy performance, covering structural and insulation materials that have already been successfully used in the market for general applications over the years. Subsequently, studies of different wood building systems (i.e., wood-frame, post-and-beam, mass timber and hybrid constructions) and energy efficiency are discussed. This is followed by a brief introduction to strategies to increase the energy efficiency of constructions. Finally, remarks and future research opportunities for wood buildings are highlighted. Some general recommendations for developing more energy-efficient wood buildings are identified in the literature and discussed. There is a lack of emerging construction concepts for wood-frame and post-and-beam buildings and a lack of design codes and specifications for mass timber and hybrid buildings. From the perspective of the potential environmental benefits of these systems as a whole, and their effects on energy efficiency and embodied energy in constructions, there are barriers that need to be considered in the future.

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Photovoltaic-Thermal Collector System for Domestic Application

Solar Energy ◽

10.1115/isec2005-76128 ◽

2005 ◽

Cited By ~ 10

Author(s):

T. T. Chow ◽

J. Ji ◽

W. He

Keyword(s):

Energy Performance ◽

Primary Energy ◽

Heat Energy ◽

Solar Thermal ◽

Test Results ◽

Thermal Systems ◽

Collector System ◽

Solar Thermal Collector ◽

Reduced Temperature ◽

Direct Attachment

Photovoltaic-thermal (PV/T) systems integrate photovoltaic and solar thermal technologies into one single system with dual production of electricity and heat energy. A typical arrangement is the direct attachment of PV modules on to a solar thermal collector surface. For a given collector surface area, the overall system energy performance is expected higher than the conventional “side-by-side” PV and solar thermal systems. In the development of PV/T collector technology using water as the coolant, the most common design follows the sheet-and-tube thermal absorber concept. Fin performance of the thermal absorber has been identified as one important factor that affects much the overall energy performance of the collector. Accordingly, an aluminum-alloy flat-box type PV/T collector prototype was constructed and tested. Our test results indicate that a high combined thermal and electrical efficiency can be achieved. The primary-energy-saving efficiency for daily exposure approaches 65% at zero reduced temperature operation. With a simple and handy design, the product is considered to be very suitable for domestic application.

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The Effect of Repeated Moisture Cycles on the Air Tightness of Traditional Clamped Vapour Barrier Joints

Journal of Sustainable Architecture and Civil Engineering ◽

10.5755/j01.sace.24.1.23232 ◽

2019 ◽

Vol 24 (1) ◽

pp. 44-51

Author(s):

Stig Geving ◽

Øyvind Norvik ◽

Lars Gullbrekken

Keyword(s):

Laboratory Test ◽

Barrier Layer ◽

Adhesive Tape ◽

Air Leakage ◽

Annual Variations ◽

Pressure Tests ◽

Air Tightness ◽

Wood Frame ◽

Structural Adhesive ◽

Center Distance

In this study it has been investigated whether and to what extent, repeated moisture cycles affect the airleakage through clamped overlap joints in the vapour barrier layer. Use of clamped joints is a traditionalway to make airtight joints in the wind- and vapour barrier used in wood frame walls in Norway and othercountries. A laboratory test has been carried out, with a total of 63 pressure tests, being carried out on 9 testsamples, consisting of overlap joints of 0.15 mm polyethylene film clamped between a wooden batten andstud. Each sample was tested seven times after repeated drying and humidification, where the moisturevalues of the sub-cycles were chosen to represent the annual variations of indoor relative humidity.The laboratory test materials were mounted with machine nails with various center spacing (150 mm,300 mm and 450 mm). The overlap joints of the vapour barrier were in the end of the test sealed withadhesive tape, revealing to what extent this over a longer period of time will be beneficial.The results showed that the first moisture cycle (drying) resulted in significant increase of air leakage forall the sample variants. Throughout the moisture cycles, a further strong leakage development for centerspacing 450 mm was observed, which was less for 300 mm, and non-existent for 150 mm. The gain ofusing structural adhesive tape was found to largely depend on the level of perforation resulting from thenails and their center distance. Adhesive tape on the joints resulted in the greatest reduction in leakagenumbers where the center distance between the nails was high, i.e. the reduction was 58% for centerdistance 450 mm. However, with shorter center distance the use of tape only decreased the air leakagebetween 22-39%, revealing the fact that a large part of the joint leakage is through the nail perforations.

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Empirical base solar reflective array accumulator design simulator

MATEC Web of Conferences ◽

10.1051/matecconf/201819711017 ◽

2018 ◽

Vol 197 ◽

pp. 11017

Author(s):

Budhy Setiawan ◽

Riska Nur Wakidah ◽

P Raden Edy ◽

D Annisa Maulidia ◽

Yulianto Yulianto ◽

...

Keyword(s):

Alternative Energy ◽

Water Mass ◽

Energy Performance ◽

Heat Energy ◽

Egg Hatching ◽

Environment Temperature ◽

Temperature Environment ◽

Trapping Method ◽

Opening And Closing ◽

And Control

Sun energy in Indonesia is 5Kwh/m2/day average per year. This alternative energy can be convert to solar thermal up to 80% efficiency, the percentage is highly significant compare to electric conversion that only has 20%. To provide any process requirement for heating, an empirical research of reflective array accumulator has been done, so that a design simulation for the accumulator has to be held. The accumulator can be used as a heat energy supplier for drying, egg hatching, food oven and other requirement. The sun energy trapping method is a reflective array. This method aims to maximize the energy captured and stored in an accumulator and has to be maintained for 24 hours by opening and closing the array. This simulator will calculated and control some input such as water mass, accumulator temperature, environment temperature, humidity and sun intensity. The array control performance to watch diffuse solar light intensity by time. The result of the simulation will give absorption storage capability, insulation capability to watch sun energy performance per day. It is expected that with the simulation, it can simplify the design of the accumulator and improve the efficiency of heat energy storage. The absorption capability perform 72%.

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Research on Amending the Energy Efficiency Provisions in the Building

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.568-570.1991 ◽

2014 ◽

Vol 568-570 ◽

pp. 1991-1994

Author(s):

Hai Hong Cui

Keyword(s):

Energy Performance ◽

Hot Water ◽

Building Regulations ◽

Thermal Transmittance ◽

Energy Performance Of Buildings ◽

Air Tightness ◽

Thermal Bridging ◽

Technical Basis ◽

Fuel Costs

The purpose of this paper is to identify the main requirements of the Building Regulations Part L1A for new dwellings. An explanation of the technical basis for energy rating is given including how they are calculated, how fuel costs are used, the role of the standard occupancy pattern, and an appreciation of the Building Research Establishment Domestic Energy Model (BREDEM). The aims and requirements of the European Directive on the Energy performance of Buildings and its implementation for new and existing domestic buildings is also considered. Design/methodology/approach – The requirements of Part L1A of the Building Regulations are developed. These relate to the thermal properties of the building fabric including insulation, thermal bridging, air tightness and glazing, the efficiency and responsiveness of heating and hot water systems, ventilation and lighting. The methodology for calculating thermal transmittance coefficients (U-values) is also demonstrated.

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Quantifying air leakage through party walls in Toronto semidetached and row-home dwellings

10.32920/ryerson.14657412.v1 ◽

2021 ◽

Author(s):

Austin Todd

Keyword(s):

Air Leakage ◽

Single Family ◽

Masonry Construction ◽

Common Wall ◽

Air Tightness ◽

Wood Frame ◽

Frame Construction ◽

New Buildings ◽

Adjacent Unit ◽

Party Wall

This study contributes to the development of quantifying and understanding building air tightness as it relates to Toronto semi-detached and row homes, particularly party walls. While infiltration characteristics of single family detached homes have been widely developed and understood, the isolation of semi-detached and row home single family dwelling units is relatively unexplored. When quantifying air leakage in a building attached to an adjacent dwelling unit, air is drawn through the exterior envelope as well as the party wall (i.e. shared common wall). The purpose of the proposed testing method, guarded blower door testing, is to isolate air leakage through the party wall from the envelope. Currently the party wall is considered a fire-rated assembly but is not part of the air barrier system. Issues associated with party wall air leakage include spread of fire, indoor air quality, transfer of tobacco smoke between dwellings, and heat loss through the party to attic detail. Data collected on buildings constructed between 1890 and 1920 (Century buildings) has been compared to the data collected on buildings constructed between 2012 to 2017 (new buildings). Air leakage has been collected on twenty-six of Century semi-detached homes with solid masonry construction and twenty-one new semi-detached/row homes of lightweight wood frame construction. Each unit was tested independently and simultaneously, or “guarded”, with the adjacent unit, to pressure neutralize allowing for quantification of envelope and party wall air leakage. Party wall leakage was found to be similar to leakage through the exterior walls. The leakage accounted for 22% of the total infiltration in Century old buildings and 38% in Modern dwellings.

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Airtightness and Heat Energy Loss of Mid-Size Terraced Houses Built of Different Construction Materials

Energies ◽

10.3390/en14196367 ◽

2021 ◽

Vol 14 (19) ◽

pp. 6367

Author(s):

Valdas Paukštys ◽

Gintaris Cinelis ◽

Jūratė Mockienė ◽

Mindaugas Daukšys

Keyword(s):

Energy Loss ◽

Energy Use ◽

Construction Materials ◽

Energy Performance ◽

Building Envelope ◽

Living Environment ◽

Heat Energy ◽

Energy Class ◽

The European Union ◽

Certification Procedure

The European Union has adopted legislation aimed to increase the use of renewable energy and improve the effectiveness of conventional-form energy use. Additional structure insulation helps to decrease heat energy loss. Airtightness of the building envelope (building airtightness) is an additional factor that determines comfortable and energy-saving living environment. The conformity of heat energy loss with the object’s design energy class is one of the mandatory indicators used in the obligatory building energy performance certification procedure. Optionally, the objects to be certified are the entire buildings or separate units (flats). There is an issue of concern whether a flat assessed as a separate housing unit would meet the requirements of design energy class depending on the location of the unit in the building. The study is aimed to determine the change in heat loss of end units in terraced houses (townhouses) as a result of various factors, leading to uneven airtightness of the building envelope. The non-destructive assessment of building airtightness was implemented through the combined use of methods, namely Blower Door Test (around 200 measurements) and Infrared Thermography. The hollow clay unit masonry showed ca. 7–11% less airtightness than the sand–lime block masonry structure. The end units were up to 20% less airtight compared to the inside units.

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Consequences of the BC Energy Step Code on Offsite Construction

Modular and Offsite Construction (MOC) Summit Proceedings ◽

10.29173/mocs126 ◽

2019 ◽

pp. 454-461

Author(s):

Guido Wimmers ◽

Alison Conroy

Keyword(s):

Energy Efficiency ◽

Construction Industry ◽

Energy Performance ◽

Efficient Solutions ◽

Wood Construction ◽

Net Zero ◽

New Construction ◽

Air Tightness ◽

Cost Efficient ◽

Near Future

In Canada, off-site construction is still the exception rather than the norm when it comes to wood construction. In Europe’s Alpine Region or Scandinavian countries, off-site construction is standard when it comes to wood construction. This paper will focus on the reasons why Canada’s wood construction industry will shift from mainly on-site to mainly off-site construction over the next 10 to 15 years. In countries with relatively demanding requirements on energy efficiency and air tightness, off-site construction has been dominating the market for more than 20 years. British Columbia adopted the BC Energy Step Code in 2017, a roadmap defining the energy efficiency of buildings over the coming years leading up to 2032, when all new construction will be required to be Net Zero ready. It is expected that the National Building Code of Canada will also encourage higher energy performance levels in the near future. Consequently, thermally better-performing envelopes will have to be produced and rigorous air tightness levels will have to be achieved for the sustainability goals given by the province. Envelope assemblies will get thicker, bulkier and heavier to meet these requirements. In this regard, a market shift to a greater amount of off-site construction is likely to be experienced to meet these targets in a controlled environment. This study is exploring the direct and indirect connections between sustainability and energy efficiency requirements given by codes to technical and cost-efficient solutions offered by industry.

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Impact of Air Tightness on the Evaluation of Building Energy Performance in Lithuania

Energies ◽

10.3390/en7084972 ◽

2014 ◽

Vol 7 (8) ◽

pp. 4972-4987 ◽

Cited By ~ 10

Author(s):

Jolanta Šadauskienė ◽

Valdas Paukštys ◽

Lina Šeduikytė ◽

Karolis Banionis

Keyword(s):

Building Energy ◽

Energy Performance ◽

Building Energy Performance ◽

Air Tightness

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Impact Analysis of Urban Morphology on Residential District Heat Energy Demand and Microclimate Based on Field Measurement Data

Sustainability ◽

10.3390/su13042070 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2070

Author(s):

Yanxue Li ◽

Dawei Wang ◽

Shanshan Li ◽

Weijun Gao

Keyword(s):

Energy Consumption ◽

Measurement Data ◽

Energy Performance ◽

Urban Morphology ◽

Area Ratio ◽

Heat Energy ◽

Space Heating ◽

Floor Area ◽

Floor Area Ratio ◽

Central Heating

In this work, we focus on investigating the relationship between urban morphology parameters and residential building space heating energy performance, comparing microclimate conditions of existing residential blocks with central heating supply. Firstly, a dataset composed of district morphological parameters that measured heat energy consumption was established. Then, effects of morphological indicators including cover ratio, average building height, and floor area ratio on building space heating energy efficiency were assessed specifically. Analysis results show that a larger floor area ratio induced a reduction in heating energy consumption density, the observed effect is notable at an initial increase of floor area ratio. Thirdly, the case study shows that the heating load of residential districts with a high built density is more sensitive to solar radiation. To further assess how and to what extent urban forms alter microclimates, on-site measurement investigated detailed changes in the thermal environment of selected residential districts before and after the operational stage of central heating supply. Analysis results demonstrate that heat energy delivered by a central heating supply could dampen the variations of local outdoor air temperatures, more notable for residential districts with a higher floor area ratio during the night period. Findings from this work would be useful for urban planners considering energy-efficient design practices.

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