Cost-efficient one-part alkali-activated mortars with low global warming potential for floor heating systems applications

Increasing building energy efficiency is one the most cost-effective ways to reduce emissions. The use of thermal insulation materials mitigates heat loss in buildings, therefore minimising heat energy needs. In recent years, several papers were published on the subject of foam alkali-activated cements with enhanced thermal conductivity. However, on those papers cost analysis was strangely avoided. This paper presents experimental results on one-part alkali-activated cements. It also includes global warming potential assessment and cost analysis. Foam one-part alkali-activated cements cost simulations considering two carbon dioxide social costs scenarios are also included. The results show that one-part alkali-activated cements mixtures based on 26%OPC + 58.3%FA + 8%CS + 7.7%CH and 3.5% hydrogen peroxide constitute a promising cost-efficient (67 euro/m3), thermal insulation solution for floor heating systems. This mixture presents a low global warming potential of 443 KgCO2eq/m3. The results confirm that in both carbon dioxide social cost scenarios the mixture 26 OPC + 58.3 FA + 8 CS + 7.7 CH with 3.5% hydrogen peroxide foaming agent is still the most cost efficient.

Energiatehokkuuden edistäminen rakentamisen ja asumisen alalla

Suomi haluaa energiatehokkuuden edelläkävijäksi maailmassa, mutta se ei onnistu ilman rakennusalan osallistumista energiatehokkuustalkoisiin. Toistaiseksi energiatehokkuuden kehitys asumisen ja rakentamisen osalta ei ole ollut niin nopeaa kuin muualla Euroopassa. Energiatehokkuustalkoiden takana on huoli ilmastomuutoksen vaikutuksista. Ilmastomuutoksen torjuminen aiheuttaa yhteiskunnalle kustannuksia, mutta pidemmällä aikavälillä se on halvempaa kuin puuttumatta jättäminen. Omakotitalojen suosio lisääntyy koko ajan ja energian kulutus niissä kasvaa. Erityisesti sähkönkäyttö lisääntyy koko ajan erityisesti viihde-elektroniikan suosion myötä. Energiatehokkuuteen yritetään vaikuttaa monenlaisilla ohjauskeinoilla, joita ovat muun muassa taloudelliset ja lainsäädännölliset ohjauskeinot. Lainsäädännön lisäksi yksi tärkeimmistä kannustimista energiatehokkuuteen on öljyn hinta. Rakennusten energiatehokkuudessa kokonaisuus ratkaisee ja erityisesti tiiveys. Julkisen sektorin rooli energiatehokkuuden edistämisessä on merkittävä sekä säädösten laatijana että esimerkin näyttäjänä. Vastuuta ilmastotalkoista halutaan jakaa myös kunnille.

Teollisuuden ja yhdyskuntien energiatehokkuusselvitykset, auditoinnit 2008–2010

Nykypäivänä energiansäästötavoitteet ovat haasteena yhä useammalle energiankuluttajalle. Tavoitteisiin päästäkseen yritykset ja kunnalliset energiankuluttajat kaipaavat usein apua kannattavien energiansäätökeinojen löytämiseksi. Erilaiset energiakatselmukset vastaavat tähän tarpeeseen ja ovat esimerkki tuloksellisesta energiansäästöstä. Lappeenrannan teknillinen yliopisto on tutkinut energiatehokkuutta pitkään erilaisissa projekteissa teollisuuden kanssa yhteistyössä. Osa LUT:n energiatehokkuustutkimusta ovat energia-auditoinnit yrityksille ja kunnille, joita LUT Energian projektin puitteissa alettiin kehittää vuoden 2008 syksyllä. Energia-auditointien fokuksena on pyritty pitämään pumppausprosessien energiatehokkuuden optimointia, sillä aihetta on tutkittu yliopistolla laajasti. Pumppausprosesseissa on todettu olevan merkittävä energiansäästöpotentiaali: pumppauksen kuluttamasta energiasta voi olla mahdollista säästää jopa 50 % erilaisilla laite- ja säästötaparatkaisuilla. Pumppausprosessien energia-auditointeja on tehty teollisuuden pumppauskohteisiin kuin myös kunnallisiin vesi-huoltolaitoksiin. Lisäksi energia-auditointien puitteissa on tutkittu energiansäästömahdollisuuksia rakennuksissa. Energiansäästökohteita etsitään sekä lämpö- että sähköenergian osalta. Energia-auditoinneissa pumppausten osalta energiansäästöpotentiaalia on todettu olevan etenkin suuren kokoluokan pumpuissa, joilla on pitkä vuosittainen käyttöaika. Myös pumppujen säätötavalla on suuri merkitys energiankulutukseen. Rakennusten osalta on pyritty selvittämään, kuinka energiankulutus jakautuu eri kulutusryhmien kesken. Säästökohteita on löydetty muun muassa rakennusten tiiviydestä, ilmanvaihdosta kuin valaistuksestakin. Monia auditointien asiakkaita on kiinnostanut etenkin led-teknologian hyödyntäminen yleisvalaistuksessa sekä muut keinot säästää valaistuksen energiankulutuksessa. Pyrkimyksenä on kehittää energia-auditointeja projektin aikana saavutettujen kokemusten avulla sekä myös liiketaloudellisessa mielessä opinnäytetutkielmien avulla. Menestyksekäs palveluliiketoiminta edellyttää määriteltyjä toimintatapoja, riittävän tarkkaa palvelujen rajausta ja koko energia-auditointiprosessin kehittämistä aina asiakassuhteen luomisesta sen jatko-hoitoon saakka.

Opistorakennusten energiatehokkuuden parantaminen

Tämän diplomityön tavoitteena on selvittää Kymenlaakson Opiston energiatehokkuuden parantamista ja tutkia onko olemassa selvästi taloudellisempi sekä ekologisempi tapa kattaa Opiston lämmitystarve verrattuna nykyisin käytössä olevaan kaukolämpöön. Työn teoriaosuudessa tehdään katsaus rakennusten energiatehokkuuteen vaikuttaviin seikkoihin, lähienergian tuotantoon ja energiatehokkuuden parantamiseen liittyvään lainsäädäntöön ja säädöksiin. Useasta rakennuksesta koostuva kansanopisto tarjoaa mielenkiintoisen pohjan selvitystyölle ja suuri lämmitystehontarve yhdistettynä monille saneerauskohteille tyypillisiin ahtaisiin teknisiin tiloihin asettaa rajoituksia lämmitysjärjestelmän suunnittelulle. Soveltavassa osuudessa määritellään reunaehdot mahdolliselle kaukolämmön korvaavalle lämmitysratkaisulle. Tutkitaan vesistölämmön hyödyntämisen mahdollisuutta ja lasketaan aurinkosähkön ja -lämmön tuotantopotentiaalia. Maalämpöjärjestelmän mitoituksessa ja taloudellisessa vertailussa käytettiin apuna maalämpöjärjestelmiä toimittavia yrityksiä. Työssä saatujen tulosten perusteella maalämpöjärjestelmä on taloudellisesti kannattava isossa kohteessa, tosin järjestelmän asennukseen liittyy ahtaiden tilojen johdosta ongelmia. Maalämpö on myös selvästi ekologisempi, kuin nykyisin käytössä oleva kaukolämpö. Aurinkosähkön tuotannolle on Kymenlaakson Opistolla hyvä potentiaali ja sähkön tuotanto kohtaa hyvin sähkön käytön.

High performance green buildings

This work aims to study and analyze strategies and measures to improve energy performance in residential and service buildings, in order to minimize energy losses and energy consumption. Due to the high energy dependence of European Union (EU), including Portugal and Slovenia, and high percentage of energy consumption in the building sector, there was a need to adopt strategies at European level with ambitious goals. This came to force EU - Member States to take measures to achieve the proposed targets for energy consumption reduction. To this end, EU - Member States have adapted the laws to their needs and formed specialized agencies and qualified experts on energy certification, which somehow evaluate buildings according to their performance. In this study, the external characteristics of the building in order to meet its thermal needs and from there to survey the existing and possible constructive solutions to be used at the envelope will be examined, in order to increase comfort and reduce the need of use technical means of air conditioning. The possibility of passive heating and ventilation systems also will be discussed. These techniques are developed in parallel with the deployment and design of the building. In this manner, to reduce the energy consumption, various techniques and technologies exploit natural resources. Thus, appear the more sustainable and efficient buildings, so-called Green Buildings have been appeared. The study ends with the identification of measures used in several buildings, proving the economic return in the medium to long term, as well as the satisfaction of their users.

Técnicas de energia elétrica sustentável aplicadas em edificações

One of the majors concerns in society today is to decrease the environmental impact caused by human activities and natural resource exploration. From this need to be more careful with the environment arose, in the field of civil construction, the term sustainable building. Projects that use natural resources rationally, without ceasing to bring comfort and functionality for customers, are becoming more a reality. This paper presents the share of electric energy in a sustainable building, with the analysis of the available renewable energies used in a project, presentation of new constructive techniques and technologies that are constantly emerging to achieve greater energy efficiency, with an appropriate use of energy received, also a decrease of the energy consumed by some devices present in a residence or business

Análise de oportunidades de poligeração em edificações e cidades

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morteros acumuladores con parafinas microencapsuladas para el aprovechamiento de la energía solar en suelos radiantes

Esta Tesis plantea la pregunta de si el uso de morteros con parafinas microencapsuladas combinado con colectores solares térmicos puede reducir el consumo de energías convencionales, en un sistema tradicional de suelo radiante. Se pretende contribuir al conocimiento acerca del efecto que produce en el edificio, el calor latente acumulado en suelos radiantes, utilizando morteros de cemento Portland con material de cambio de fase (PCM), en conjunto con la energía solar. Para cumplir con este propósito, la investigación se desarrolla considerando diversos aspectos. En primer lugar, se revisa y analiza la documentación disponible en la actualidad, de almacenamiento de energía mediante calor latente en la construcción, y en particular la aplicación de microcápsulas de PCM en morteros y suelos radiantes. También se revisa la documentación relacionada con la aplicación de la energía solar térmica y en suelo radiante. Se analiza la normativa vigente respecto al material, a los colectores solares y al suelo radiante. Se verifica que no hay normativa relacionada con mortero-PCM, debido a esto se aplica en la investigación una adaptación de la existente. La fase experimental desarrollada esta principalmente dirigida a la cuantificación, caracterización y evaluación de las propiedades físicas, mecánicas y térmicas del mortero de cemento Portland con parafinas microencapsuladas. Los resultados obtenidos y su análisis, permiten conocer el comportamiento de este tipo de morteros, con las diferentes variables aplicadas en la investigación. Además, permite disponer de la información necesaria, para crear una metodología para el diseño de morteros con parafina microencapsulada, tanto del punto de vista de su resistencia a la compresión y contenido de PCM, como de su comportamiento térmico como acumulador de calor. Esto se logra procesando la información obtenida y generando modelos matemáticos, para dosificar mezclas, y predecir la acumulación de calor en función de su composición. Se determinan los tipos y cantidades de PCM, y el cemento más adecuado. Se obtienen importantes conclusiones respecto a los aspectos constructivos a considerar en la aplicación de morteros con PCM, en suelo radiante. Se analiza y evalúa la demanda térmica que se puede cubrir con el suelo radiante, utilizando morteros con parafina microencapsulada, a través de la acumulación de energía solar producida por colectores solares, para condiciones climáticas, técnicas y tipologías constructivas específicas. Se determina que cuando los paneles cubren más de 60 % de la demanda por calefacción, se puede almacenar en los morteros con PCM, el excedente generado durante el día. Se puede cubrir la demanda de acumulación de energía con los morteros con PCM, en la mayoría de los casos analizados. Con esto, se determina que el uso de morteros con PCM, aporta a la eficiencia energética de los edificios, disminuyendo el consumo de energías convencionales, reemplazándola por energía solar térmica. En esta investigación, el énfasis está en las propiedades del material mortero de cemento-PCM y en poder generar metodologías que faciliten su uso. Se aborda el uso de la energía solar, para verificar que es posible su acumulación en morteros con PCM aplicados en suelo radiante, posibilitando el reemplazo de energías convencionales. Quedan algunos aspectos de la aplicación de energía solar a suelo radiante con morteros con PCM, que no han sido tratados con la profundidad que requieren, y que resultan interesantes de evaluar en este tipo de aplicaciones constructivas, como entre otros, los relacionados con la cuantificación de los ahorros de energía en las diferentes estaciones del año, de la estabilización de temperaturas internas, su análisis de costo y la optimización de este tipo de sistemas para utilización en verano, los que dan pie para otras Tesis o proyectos de investigación. ABSTRACT This Thesis proposes the question of whether the use of mortars with microencapsulated paraffin combined with solar thermal collectors can reduce conventional energy consumption in a traditional heating floor system. It aims to contribute to knowledge about the effect that it has on the building, the latent heat accumulated in heating floor, using Portland cement mortars with phase change material (PCM), in conjunction with solar energy. To fulfill this purpose, the research develops it considering various aspects. First, it reviews and analyzes the documentation available today, about energy storage by latent heat in the building, and in particular the application of PCM microcapsules in mortars and heating floors. It also reviews the documentation related to the application of solar thermal energy and heating floor. Additionally, it analyzes the current regulations regarding to material, solar collectors and heating floors. It verifies that there aren’t regulations related to PCM mortar, due to this, it applies an adaptation in the investigation. The experimental phase is aimed to the quantification, mainly, characterization and evaluation of physical, mechanical and thermal properties of Portland cement mortar with microencapsulated paraffin. The results and analysis, which allow us to know the behavior of this type of mortars with different variables applied in research. It also allows having the information necessary to create a methodology for designing mortars with microencapsulated paraffin, both from the standpoint of its resistance to compression and PCM content, and its thermal performance as a heat accumulator. This accomplishes by processing the information obtained, and generating mathematical models for dosing mixtures, and predicting heat accumulation depending on their composition. The research determines the kinds and amounts of PCM, and the most suitable cement. Relevant conclusions obtain it regarding constructive aspects to consider in the implementation of PCM mortars in heating floor. Also, it analyzes and evaluates the thermal demand that it can be covered in heating floor using microencapsulated paraffin mortars, through the accumulation of solar energy produced by solar collectors to weather conditions, technical and specific building typologies. It determines that if the panels cover more than 60% of the demand for heating, the surplus generated during the day can be stored in PCM mortars. It meets the demand of energy storage with PCM mortars, in most of the cases analyzed. With this, it determines that the use of PCM mortars contributes to building energy efficiency, reducing consumption of conventional energy, replacing it with solar thermal energy. In this research approaches the use of solar energy to determine that it’s possible to verify its accumulation in PCM mortars applied in heating floor, enabling the replacement of conventional energy. The emphasis is on material properties of PCM mortar and, in order to generate methodologies to facilitate their use. There are some aspects of solar energy application in PCM mortars in heating floor, which have not been discussed with the depth required, and that they are relevant to evaluate in this kind of construction applications, including among others: the applications related to the energy savings quantification in different seasons of the year, the stabilizing internal temperatures, its cost analysis and optimization of these systems for use in summer, which can give ideas for other thesis or research projects.

Cost-effective energy and carbon emission optimization in building renovation – A case-study in a low income neighbourhood

Construction sector is one of the major responsible for energy consumption and carbon emissions and renovation of existing buildings plays an important role in the actions to mitigate climate changes. Present work is based on the methodology developed in IEA Annex 56, allowing identifying cost optimal and cost effective renovation scenarios improving the energy performance. The analysed case study is a residential neighbourhood of the municipality of Gaia in Portugal. The analysis compares a reference renovation scenario (without improving the energy performance of the building) with a series of alternative renovation scenarios, including the one that is being implemented.

Benefits from energy related building renovation beyond costs, energy and emissions

The relevance of the building sector in the global energy use as well as in the global carbon emissions, both in the developed and developing countries, makes the improvement of the overall energy performance of existing buildings an important part of the actions to mitigate climate changes. Regardless of this potential for energy and emissions saving, large scale building renovation has been found hard to trigger, mainly because present standards are mainly focused on new buildings, not responding effectively to the numerous technical, functional and economic constraints of the existing ones. One of the common problems in the assessment of building renovation scenarios is that only energy savings and costs are normally considered, despite the fact that it has been long recognized that investment on energy efficiency and low carbon technologies yield several benefits beyond the value of saved energy which can be as important as the energy cost savings process. Based on the analysis of significant literature and several case studies, the relevance of co-benefits achieved in the renovation process is highlighted. These benefits can be felt at the building level by the owner or user (like increased user comfort, fewer problems with building physics, improved aesthetics) and should therefore be considered in the definition of the renovation measures, but also at the level of the society as a whole (like health effects, job creation, energy security, impact on climate change), and from this perspective, policy makers must be aware of the possible crossed impacts among different areas of the society for the development of public policies.

IEA EBC Annex56 vision for cost effective energy and carbon emissions optimization in building renovation

Building sector has become an important target for carbon emissions reduction, energy consumption and resources depletion. Due to low rates of replacement of the existing buildings, their low energy performances are a major concern. Most of the current regulations are focused on new buildings and do not account with the several technical, functional and economic constraints that have to be faced in the renovation of existing buildings. Thus, a new methodology is proposed to be used in the decision making process for energy related building renovation, allowing finding a cost-effective balance between energy consumption, carbon emissions and overall added value.

A data framework for measuring the energy consumption of the non-domestic building stock

The transition to a low-carbon economy urgently demands better information on the drivers of energy consumption. UK government policy has prioritized energy efficiency in the built stock as a means of carbon reduction, but the sector is historically information poor, particularly the non-domestic building stock. This paper presents the results of a pilot study that investigated whether and how property and energy consumption data might be combined for non-domestic energy analysis. These data were combined in a ‘Non-Domestic Energy Efficiency Database’ to describe the location and physical attributes of each property and its energy consumption. The aim was to support the generation of a range of energy-efficiency statistics for the industrial, commercial and institutional sectors of the non-domestic building stock, and to provide robust evidence for national energy-efficiency and carbon-reduction policy development and monitoring. The work has brought together non-domestic energy data, property data and mapping in a ‘data framework’ for the first time. The results show what is possible when these data are integrated and the associated difficulties. A data framework offers the potential to inform energy-efficiency policy formation and to support its monitoring at a level of detail not previously possible.

Building communities: reducing energy use in tenanted commercial property

Reducing energy use in tenanted commercial property requires a greater understanding of ‘buildings as communities’. Tenanted commercial properties represent: (1) the divergent communities that share specific buildings; and (2) the organizational communities represented by multi-site landlord and tenant companies. In any particular tenanted space the opportunity for environmental change is mediated (hindered or enabled) through the lease. This discussion draws on theoretical and practical understandings of (1) the socio-legal relationships of landlords, tenants and their advisors; (2) the real performance of engineering building services strategies to improve energy efficiency; (3) how organizational cultures affect the ability of the sector to engage with energy-efficiency strategies; and (4) the financial and economic basis of the relationship between owners and occupiers. The transformational complexity stems from: (1) the variety of commercial building stock; (2) the number of stakeholders (solicitors, investors, developers, agents, owners, tenants and facilities managers); (3) the fragmentation within the communities of practice; and (4) leasehold structures and language. An agenda is proposed for truly interdisciplinary research that brings together both the physical and the social sciences of energy use in buildings so that technological solutions are made effective by an understanding of the way that buildings are used and communities behave.

Influencing energy efficient occupant behavior through improved building and control design

There is growing pressure on the construction industry to deliver energy efficient, sustainable buildings but there is evidence to suggest that, in practice, designs regularly fail to achieve the anticipated levels of in-use energy consumption. One of the key factors behind this discrepancy is the behavior of the building occupants. This paper explores how insights from experimental psychology could potentially be used to reduce the gap between the predicted and actual energy performance of buildings. It demonstrates why traditional methods to engage with the occupants are not always successful and proposes a model for a more holistic approach to this issue. The paper concludes that achieving energy efficiency in buildings is not solely a technological issue and that the construction industry needs to adopt a more user-centred approach.

Integrated analisis of building and users: a way to reduce energy consuption

In many countries buildings are responsible for a substantial part of the energy consumption, nd it varies according to their energetic and environmental performances. The potential for major reductions in buildings consumption have bee well documented in Brazil. Opportunities have been identified throughout the life cycle of the buildings, due of projects in diverse locations without the proper adjustments. This article offers a reflection about project processes and how its understanding can be conducted in an integrated way, favoring the use of natural resources and lowering energy consumption. It concludes by indicating that the longest phase in the life cycle of a building is also the phase responsible for its largest energy consumption, not only because of its duration but also for the interaction with the end user. Therefore, in order to harvest the energy cost reduction potential from future buildings designers need a holistic view of the surrounding, end users, materials and methodologies.