Annex 38 Sweden LindasGoteborg

8/3/2019 Annex 38 Sweden LindasGoteborg

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Gteborg, Sweden

IEA SCH Task 28 / ECBCS Annex 38

Sustainable Solar HousingInternational Energy Agency


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The project

In an environment of great natural beauty at Linds,20 km south of Gteborg, the city owned companyEgnahemsbolaget has built 20 terrace houses inwhich a traditional heating system has beenreplaced by a heat exchanger in combination withan exceptionally well insulated construction. Solarcollectors on the roof provide half the energyneeded for the supply of hot water.

The terrace houses were designed by EFEMarkitektkontor, and are the result of a researchproject extending over four years, carried out incooperation with Chalmers University ofTechnology, Energy and Building Design at LundUniversity, the Swedish National Testing andResearch Institute (SP) and the Swedish Council forBuilding Research (Formas).

The buildings were designed to provide a pleasantindoor environment with minimum energy use. The

courtyard facade towards the south has largewindows to make full use of solar heat. Balconiesand roof overhang provide protection againstexcessive solar radiation during the summer. Owingto the terrace construction with houses of 11 mdepth, there are few external walls, and these areexceptionally well insulated and airtight. The roofwindow above the staircase gives light in the middleof the house, and is also used for effectiveventilation in the summer.

Objectives

The goals were to show that it is possible to buildhouses in a Scandinavian climate with no specialheating system and to normal costs.

Marketing strategy

There were no special efforts done to market thehouses. They were advertised as Comfortablerow houses in a beautiful nature with a lowenergy demand.

Building construction U- value: W/m2K

External wall: 0.10Framed construction with 43 cm insulation.

Roof: 0.08Masonite beams with 48 cm insulation.

Floor: 0.11Concrete slab laid on 25 cm insulation.

Windows: 0.85Three pane windows with two metallic coats andkrypton or argon fill. Energy transmittance is 50%and light transmittance is 64-68%.

External door: 0.80

Air tightness 0.3 ach at +/-50 PaAir heat exchanger, =80 85% P=70 W


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Technical systems: Ventilation and Heating

The exhaust air in a counter flow heat exchanger heatssupply air. It provides 80% heat recovery. In thesummer the heat exchanger can be turned off(automatic bypass) and the house ventilated withoutpreheating of the supply air and by opening windows.

Part of the space heating demand is covered by heatgains from the occupants, ca 1200 kWh/year andenergy efficient appliances and lighting, 2900 kWh/yearwhich partly is useful to heat the building. Theremaining space heating demand is covered by electricresistance heating, 900 W, in the supply air.

The houses have been designed for normalScandinavian climatic conditions. Very low outdoortemperatures over extended periods are rare and areregarded extreme. In such cases the indoortemperature may drop by a degree or two.

The houses are neither more nor less complicated tolive in than ordinary houses. If it is cold outside, theoccupants do not open the windows to create a throughdraft. If it is warm and sunny, they lower the blinds orthe awnings outside the southerly windows.

Hot water supply

Solar collectors of 5 m2 per house provide the energyfor half the hot water demand. The 500 l storage tank isequipped with an electric immersion heater to cover therest of the demand.

Energy performance

The energy performance of the buildings are ascalculated. The average energy consumption ishigher than the calculated according to user habits(higher indoor temperature, more TV-sets, homecomputers, stand by appliances). The variation in

energy use for the house units is large. The totaldelivered energy demand varies between 45 and 97kWh/ma for different households. Savingscompared to houses built according to the nationalbuilding code and practice is 50 75%.

Heating of space and ventilation air: 14.3 kWh/m(electricity)Domestic hot water (electricity): 15.2 kWh/mFans and pumps: 6.7 kWh/mLighting and appliances: 31.8 kWh/mDelivered energy demand: 68.0 kWh/m

Domestic hot water (solar energy): 8.9 kWh/mTotal monitored energy demand: 76.9 kWh/m


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www.iea-shc.org www.ecbcs.org

Illustration: Hans Grnlund, EFEM arkitektkontor

Planning toolsFor the energy performance, passive solar energydesign and for the indoor climate the computerprogram DEROB LTH was used (Maria Wall).

Cost and benefits

Building costs are estimated to be normal. The extrameasures in the form of greater air tightness andinsulation, adaptation to "passive solar heating" andheat recovery in the ventilation are paid for by themuch lower costs of the heating system and thesavings in energy costs .

Financing

The project was in the planning and evaluationphase financed by Formas and EU (through theCEPHEUS project). Investment costs were carriedby Egnahemsbolaget, Gteborg.

Innovative products

Swedish standard products have been used.

Project teamClient:EgnahemsbolagetContractor: PEABArchitect: EFEM arkitektkontor, GteborgConstructional engineer: WSP, GteborgHVAC consultant:Bengt Dahlgren AB, GteborgElectrical services consultant:Probeko, GteborgSite works consultant:Landskapsgruppen, Gteborg

Those in charge of the different areas of the

research project:Project manager: Hans Eek,EFEM arkitektkontor, GteborgEnergy and Building Design LTH: Maria WallBuilding Physics CTH: Carl-Erik Hagentoft andFredrik SthlThe Swedish National Testing and ResearchInstitute: Svein Ruud and Leif Lundin

Contact person

Hans Eek ([email protected])Maria Wall ([email protected])

Literature and links

http://www.ebd.lth.se click Researchhttp://www.goteborg2050.nu

efemarkitektkontor

Documents

Annex 38 Sweden LindasGoteborg