Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standards

Introduction: South Africa is ranked among the 20 highest greenhouse gas (GHG) emitters worldwide, mainly due to its heavy reliance on coal for energy. The residential building industry can play a significant role towards the minimization of both GHG emissions and energy consumption. This research a...

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Main Authors: Emmanuel Kabundu, Sijekula Mbanga, Brink Botha, Emma Ayesu-Koranteng
Format: Article
Language:English
Published: Frontiers Media S.A. 2024-01-01
Series:Frontiers in Built Environment
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fbuil.2023.1305029/full
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author Emmanuel Kabundu
Sijekula Mbanga
Brink Botha
Emma Ayesu-Koranteng
author_facet Emmanuel Kabundu
Sijekula Mbanga
Brink Botha
Emma Ayesu-Koranteng
author_sort Emmanuel Kabundu
collection DOAJ
description Introduction: South Africa is ranked among the 20 highest greenhouse gas (GHG) emitters worldwide, mainly due to its heavy reliance on coal for energy. The residential building industry can play a significant role towards the minimization of both GHG emissions and energy consumption. This research assesses the beneficial impacts of utilizing wall envelope insulation measures using five insulation materials, for a detached residential building, within the seven energy zones of South Africa in accordance with the South African National code for Building energy efficiency (SANS10400-XA).Methods: Lifecycle analysis (for 50 years), regression methods and sequential search techniques of building energy modelling were used to determine both the energy saving implications of adopting the insulation materials (at various levels of thickness), and their corresponding energy payback periods. The study area consisted of eight selected locations representing all the seven energy zones in South Africa (Welkom, Witbank, Thohoyandou, Cape Town, Pretoria, Ixopo, Sutherland, and Fraserburg).Results: Sutherland (zone 6), Cape Town (zone 4) and Fraserburg (zone 7) benefitted most from energy savings due to application of insulation measures. Witbank (Zone 2), Thohoyandou (zone 3) and Pretoria (zone 5) never benefitted from application of wall envelope insulation (in terms of energy savings). Cellulose and straw yielded the lowest payback periods. Generally, polyurethane yielded the highest net energy savings at lower insulation thickness levels, while cellulose was preferable at higher insulation thickness levels in Welkom (zone1) Cape Town (zone 4), Ixopo (zone 5H), Sutherland (zone 6) and Fraserburg (zone 7).Discussion: Lower optimal wall envelope insulation thicknesses (that maximized energy savings) appeared to correspond to locations with higher annual temperature ranges. Higher temperature ranges (hence, higher degree days) would ensure that more energy is saved in order to keep the indoor temperatures within the acceptable comfort limits, due to application of insulation. However, the selection of insulation material is also influenced by other factors such as resistance to insect and mould attack (which easily affect bio-insulation materials), fire retardancy, durability (which affects cellulose), sound proofing, structural strength, and resistance to water vapour.
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spelling doaj.art-29a46ad2a7c0414785316c947aa676262024-01-24T04:34:49ZengFrontiers Media S.A.Frontiers in Built Environment2297-33622024-01-01910.3389/fbuil.2023.13050291305029Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standardsEmmanuel Kabundu0Sijekula Mbanga1Brink Botha2Emma Ayesu-Koranteng3Department of Building and Human Settlements, Nelson Mandela University, Gqeberha, South AfricaDepartment of Building and Human Settlements, Nelson Mandela University, Gqeberha, South AfricaDepartment of Construction Management, Nelson Mandela University, Gqeberha, South AfricaDepartment of Building and Human Settlements, Nelson Mandela University, Gqeberha, South AfricaIntroduction: South Africa is ranked among the 20 highest greenhouse gas (GHG) emitters worldwide, mainly due to its heavy reliance on coal for energy. The residential building industry can play a significant role towards the minimization of both GHG emissions and energy consumption. This research assesses the beneficial impacts of utilizing wall envelope insulation measures using five insulation materials, for a detached residential building, within the seven energy zones of South Africa in accordance with the South African National code for Building energy efficiency (SANS10400-XA).Methods: Lifecycle analysis (for 50 years), regression methods and sequential search techniques of building energy modelling were used to determine both the energy saving implications of adopting the insulation materials (at various levels of thickness), and their corresponding energy payback periods. The study area consisted of eight selected locations representing all the seven energy zones in South Africa (Welkom, Witbank, Thohoyandou, Cape Town, Pretoria, Ixopo, Sutherland, and Fraserburg).Results: Sutherland (zone 6), Cape Town (zone 4) and Fraserburg (zone 7) benefitted most from energy savings due to application of insulation measures. Witbank (Zone 2), Thohoyandou (zone 3) and Pretoria (zone 5) never benefitted from application of wall envelope insulation (in terms of energy savings). Cellulose and straw yielded the lowest payback periods. Generally, polyurethane yielded the highest net energy savings at lower insulation thickness levels, while cellulose was preferable at higher insulation thickness levels in Welkom (zone1) Cape Town (zone 4), Ixopo (zone 5H), Sutherland (zone 6) and Fraserburg (zone 7).Discussion: Lower optimal wall envelope insulation thicknesses (that maximized energy savings) appeared to correspond to locations with higher annual temperature ranges. Higher temperature ranges (hence, higher degree days) would ensure that more energy is saved in order to keep the indoor temperatures within the acceptable comfort limits, due to application of insulation. However, the selection of insulation material is also influenced by other factors such as resistance to insect and mould attack (which easily affect bio-insulation materials), fire retardancy, durability (which affects cellulose), sound proofing, structural strength, and resistance to water vapour.https://www.frontiersin.org/articles/10.3389/fbuil.2023.1305029/fullenergy efficiencylifecycle analysis (LCA)embodied emissionsembodied energysource energysite energy
spellingShingle Emmanuel Kabundu
Sijekula Mbanga
Brink Botha
Emma Ayesu-Koranteng
Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standards
Frontiers in Built Environment
energy efficiency
lifecycle analysis (LCA)
embodied emissions
embodied energy
source energy
site energy
title Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standards
title_full Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standards
title_fullStr Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standards
title_full_unstemmed Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standards
title_short Relative comparison of the benefits of wall envelope insulation materials in the South African energy zones, subject to the new national building energy efficiency standards
title_sort relative comparison of the benefits of wall envelope insulation materials in the south african energy zones subject to the new national building energy efficiency standards
topic energy efficiency
lifecycle analysis (LCA)
embodied emissions
embodied energy
source energy
site energy
url https://www.frontiersin.org/articles/10.3389/fbuil.2023.1305029/full
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