Analys av köldbryggor, fönsterplacering och värmesystem för ett låg-/plusenergihus
2012 (Swedish)Independent thesis Basic level (professional degree), 10 credits / 15 HE credits
Student thesisAlternative title
An analyze of thermal bridges, placing of windows and heating systems for a low-energy house (English)
Abstract [sv]
Miljo och energi ar tva faktorer som blir allt viktigare, och energisnala hus har nu
funnits en tid pa marknaden. Att ta lagenergihus ett steg langre, och gora
plusenergihus som levererar mer energi an vad den gor av med, ar inte lika val
testat i Sverige annu. Da tjockleken pa vaggarna blir storre ar det ocksa viktigare
att hitta tekniker som minskar koldbryggor vid anslutningar.
For att forsta hur man pa basta satt ska utforma och konstruera dessa hus
behovs kunskap om material, koldbryggor, byggnadsdetaljer, klimat och
uppvarmningssystem. Bland annat har en analys av vilka olika varmesystem som
passar bra for ett lag-/plusenergihus gjorts i denna examensrapport, med stod av
referensobjekt. For att huset i framtiden ska kunna utnyttjas som ett plusenergihus
behovs ett system som har kapacitet att lagra energi under en kortare tid. Istallet
for att anvanda bergvarme gar det exempelvis att installera solfangare, som aven
fungerar bra i Sverige, och vintertid racker det med en braskamin.
I samarbete med Trivselhus har generella principer for koldbryggor tagits fram
genom berakningar for hand och i programmet UNorm version 2011:1. Resultatet
visar att det kritiska omradet vid anslutningen platta pa mark och vagg ar syllen,
och det ar viktigt att dessa anslutningar blir sa tata som mojligt. For att minska
varmeflodet i detta kritiska omrade ar det en fordel att dela syllarna och att isolera
emellan dem. For koldbryggor kring fonster har resultaten fran berakningar, bade
for hand och genom Unorm, visat att koldbryggorna ar storre i en tjock vagg. I en
tjock vagg ar varmeflodet trogare och vaggen upplevs som kall. Detta har inte sa
stor inverkan pa sjalva innetemperaturen, men vaggen far ett mildare uttryck.
En solstudie i Revit Architecture har utforts dar fonstren forst har placerats i
ytterkant pa fasad och sedan i innerkant for att undersoka vilken skillnad det gor i
solinstralning och transmissioner fran och till byggnaden. Nar fonstren placeras i
innerkant bildar vaggen en sollada och skuggar fonstret mer an om det ligger i
fasad. Utifran det har resultatet ser man att det spelar en stor roll var man placerar
sina fonster. Sommartid forloras en hel del solenergi om man placerar fonstren i
innerkant av fasad, istallet for i ytterkant. En hel del gratisenergi kan utvinnas om
man placerar fonstren i ytterkant av fasaden. Skillnaden i solinstralning for de
olika placeringarna motsvarar nastan en femtedel utav en villas totala
arsforbrukning.
Abstract [en]
Environment and energy are two factors that have become more important as the
development in general is increasing over the world. Low-energy houses have
been on the market for a while now, and the development of buildings is moving
towards houses that can produce energy both to deliver and to supply the house
itself. As the thickness of the walls increases it becomes more important to reduce
the thermal bridges among construction details, for example connection between
wall and slab.
To understand how to design and construct these buildings, knowledge about
material, thermal bridges, building details, climate and heating systems is required.
In this thesis, analyzes have been done that concerns heating systems that are
suitable for a low energy house with help from references to similar projects.
Together with the Swedish company Trivselhus general principles for thermal
bridges have been developed, these principles are based on calculations by hand
and by using software called UNorm 2011-1. The result shows a critical part
among the connection between the concrete slab and the wall. Also the joist is
really important to make sure it is dense. To reduce the heat flow in this critical
area, it makes sense to separate the joists and insulate between them. For thermal
bridges around the windows, the results of calculations, both by hand and by
UNorm, showed that thermal bridges are greater in a thick wall. In a thick wall the
heat flow is slower and the wall is perceived as cold. This has not much effect on
the actual indoor temperature, but the wall may get a milder impression.
In Autodesk’s Revit Architecture a sun study has been created to see if there is
any difference between having the windows placed in the facade or in the inner
part of the facade. Will it make any difference for the shading of the window and
how will it affect the sun insolation and the transmission of energy in and out of
the window? When the window is further into the wall, the wall creates a box that
increases the shading of the window. Based on this result you can see that the
placing of the windows does matter. During the summertime a lot of solar energy
will be lost if the window is placed further in to the facade. The transmission from
the building, through the windows, is not that big, but the greatest difference can
be seen in the total solar insolation. A lot of energy can be extracted from the sun
insolation, if you place the windows right, which is in the outside of the facade.
Almost one fourth of a buildings total energy consumption of a year can be
received from the solar energy only through the windows, if they are placed in the
outside of the facade.
Place, publisher, year, edition, pages
2012. , p. 90
Keywords [sv]
Byggnadsteknik, Köldbryggor, Lågenergihus, Solstudie, Transmission, Värmesystem, Värmeflöde, UNorm
National Category
Building Technologies
Identifiers
URN: urn:nbn:se:hj:diva-20793OAI: oai:DiVA.org:hj-20793DiVA, id: diva2:611757
External cooperation
Trivselhus
Subject / course
JTH, Civil Engineering
Uppsok
Technology
Supervisors
Examiners
2013-04-172013-03-112013-04-17Bibliographically approved