Sun capture systems as retrofitting solutions for the envelope GROUP - - PowerPoint PPT Presentation

Sun capture systems as retrofitting solutions for the envelope GROUP 3

Antonio Manuel Oliveira Alessia Gadotti Vesna Komljenović Sonja Jurošević

Problem statement: Orientation of the buildings and the apartments, together with the current state of the facades results in inhabitants managing their own indoor climate. Main question of research: To what extent would turning the south facade into glazed terraces be an energy and cost effective strategy? Methodology:

• Climate analysis
• Location analysis
• Strategies propositions
• Analysis of a solution for retrofitting the building

envelope with systems for solar capture

• Energy simulation analysis
• Compare the energy effectiveness and cost

effectiveness of the current state and glazed solution

Cfa climate zone

(Koppen-Geiger climate classification system)

Climate analysis: Cfa Humid Subtropical Climate

Main characteristics:

• Hot, humid summers
• Mild to cool winters, often snowfall and ice
• Strong seasonal winds
• Significant amount of precipitation occurs in all seasons
• Occasionally strong seasonal winds
• Clear distinction between all four seasons

Conclusions:

Comfortable ≈24% of time from May until September

Recommende nded d strate tegie gies for this is clim limate zone Cfa (in in gener eral) l): :

/taken from Climate Consultant/

* Sunny wind-protected areas to extend living areas in cool weather * Winter sun should penetrate into daytime used spaces with functions that coincide with solar

• rientation

* Natural ventilation: night-time "cooling" in high mass interior surfaces (reducing air conditioning needs) * Trees - not in front of passive solar gain windows (neither conifer nor deciduous): but beyond 45 degrees * Extra insulation: increase comfort + cost effective * Buildings and vegetation facing coldest winds as insulating layer * Overhangs + Glazing on the south facades * Window overhangs - operate sunshades * Insulating blinds or heavy draperies - to reduce winter time heat loses

Location analysis:

• Position of the block in the city
• Environment
• Problems on the neighbourhood level
• Potential retrofitting strategies on the neighbourhood

level:

• heat pumps
• pv or solar thermal on the rooftops and façade
• regulating the vegetation
• regulating the parking

Build ildin ing le level: l: B8 build ilding ing

• Long: 280 m, 10 storeys x 50 apartments/story
• Problems:
• façade orientation
• apartments orientation
• individual problem solving
• Positive issues:
• repetition of main aspects
• sun exposure of roof and façade surfaces
• construction system

Current situation Esthetical value:

January 16:00 Sola lar radia iatio tion analy lysis sis (Desig sign build ilder) August 16:00 January 09:00 August 09:00

SOLAR RADIATION IN SERBIA POTENTIAL

• The potential of solar energy

is 16,7%

• Average daily energy of

global radiation for flat surface during winter ranges between 1.1 kWh/m² in the north and 1.7 kWh/m² in the south, and during the summer period between 5.4 kWh/m² in the north and 6.9 kWh/m² in the south

• The most favorable areas in

Serbia record a large number

• f sunny hours and the annual

ratio of real radiation and total potential is approximately 50% (SOLAR PHOTOVOLTAIC POWER IN SERBIA, DR LJUBISAV STAMENIĆ, December 2009 )

Example ple: : archit hitecture ecture of Santia tiago go de Compo post stela ela

Existin sting enve velop lope

1. Prefabricated elements panels‐enclosing of the building's load‐bearing structure 2. Poor thermal performance and thermal bridges 3. Condensation problems

Layers Thickness [m] Heat conductivity (λ) [W/mK] Specific heat (c) [J/kgK] Density (ρ) [kg/m

3]

Heat resistance [m

2k/W]

1 Concrete 0.060 1.650 1000 2200 0.04 2 EPS 0.060 0.042 1450 20 1.43 3 Concrete 0.080 1.650 1000 2200 0.05 Total thickness [cm] 20.0 1.7

U-value [W/m2K] Thermal lag [h] 0.59 4.39

45 3 2 1 0.000 500.000 1000.000 1500.000 2000.000 2500.000

• 0.5

9.5 19.5 29.5 39.5

Pressure [Pa] Sd [m] VAPOUR PRESSURES

BIPV – Building Integrated Photovoltaics

Energy gy efficiency ciency enve velope lope retrof rofitt itting ing

Prefabricated timber elements panels as enclosing of the building's load‐bearing structure

TES Energy Facade (NTNU research) IEA SHC Task 47

• 1. Improvement of the insulation capabilities of the façade by a reduction of its U-value.
• 2. Renewal of the windows with airtight and thermal resistant frames and better

insulating glass.

• 3. Avoidance of constructional, material and geometric thermal bridges by improved

constructions.

• 4. Avoidance of uncontrolled ventilation energy losses by an airtight building envelope.

Energy gy efficiency ciency enve velope lope retrof rofitt itting ing

Layers Thickness [m] Heat conductivity (λ) [W/mK] Specific heat (c) [J/kgK] Density (ρ) [kg/m

3]

Heat resistance [m

2k/W]

Rsi 0.130 1 Plasterboard 0.013 0.210 1050 900 0.06 2 Adaptation layer 0.060 0.033 1030 70 1.82 3 Cellulose 0.240 0.058 1600 85 4.14 4 OSB panel 0.013 0.130 1700 680 0.10 5 Cladding 0.030 0.600 1000 2200 0.05 Rse 0.040 Total thickness [cm] 35.5 6.3 U-value [W/m2K] Thermal lag [h] 0.16 20.39

Su Sunspace space

Solar comb façade (air space + glass ≈ 9mm)

Bui uildin ding g model l

Model results

Zone 1 / Widtg Sun Esp a Sul

Estimating financial payback time

Social-economic situation and incentives for building retrofitting:

Problems:

• Income
• Unemployment

Possible solutions:

• Municipality Incentives
• Bank loans
• International funds

Thank for your attention!