1. Passive solar systems for building renovation
ERASMUS IP Sustainable Refurbishment, Retrofit, Energy Management in Housing
Passive solar systems for building renovation
Maria Isabel Abreu
19th May, Corte

2. In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer This is called passive solar design because, unlike active solar systems, it doesn't involve the use of mechanical and electrical devices.
The key to designing a passive solar building is to best take advantage of the local climate

3. These technologies:
- convert sunlight into usable heat (water, air, thermal mass)
cause air-movement for ventilating
protect from sunlight
with little use of other energy sources
Passive heating use
Passive cooling use (reduce summer cooling requirements)

4. integration passive solar SOLUTIONS IN Building renovation
It is recognized that the construction technologies for renovation are relatively new and, unfortunately, most R&D and products development is directed toward new construction
There are some passive solutions that are possible to apply
With the propose of reaching similar energy performance requirements as those established for new buildings, it is possible to adopt in existent buildings a range of passive
energy-renovation-solutions

5. Key passive solar building design concepts
Direct solar gain
Indirect solar gain
South facing glass
Isolated solar gain
Thermal mass to absorb, store, and distribute heat
Insulation and glazing
Passive cooling

6. Direct gain, indirect gain and isolated gain/Thermal mass
The goal of all passive solar heating systems is to capture the sun’s heat within the building’s elements and release that heat during periods when the sun is not shining
At the same time that the building’s elements (or materials) is absorbing heat for later use, solar heat is available for keeping the space comfortable

7. Direct solar gain
The actual living space is a solar collector, heat absorber and distribution system
South facing glass admits solar energy into the house where it strikes directly and indirectly thermal mass materials such as masonry floors and walls
The direct gain system will use 60–75% of the sun’s energy striking the windows

8. Direct solar gain/Heat storage
The ratio of solar exposed glass to exposed thermal mass in a room is critical and varies significantly between climates and designs
Too much thermal mass for the available solar heat input creates a heat sink and increases auxiliary heating needs.
Insufficient thermal mass causes daytime overheating and rapid heat loss at night
Use 6 to 9 m2 of living space floor area for each 1 m2 of south glazing area

9. Indirect solar gain
Thermal mass is located between the sun and the living space
The thermal mass absorbs the sunlight that strikes it and transfers it to the living space by conduction and convection
The indirect gain system will use 30–45% of the sun’s energy striking the glass near the thermal mass wall
Efficiency can suffer from slow response (thermal lag) and heat losses at night

10. Indirect solar gain/Heat storage
Thermal storage walls – Trombe walls

11. Isolated solar gain
Have its integral parts separate from the main living space
The system use solar energy to passively move heat from or to the living space using a fluid, such as water or air by natural convection or forced convection
The isolated gain system will use 15–30% of the sunlight striking the glazing toward heating the adjoining living areas
Sunrooms
Convective loop through an air collector to a storage system inside the building

12. Isolated solar gain
Sunrooms
Convective loop through an air collector to a storage system inside the building

13. Sunrooms
Use a dark color for the thermal wall
The thickness of the thermal wall should be cm for adobe or earth materials, cm for brick, cm for (dense) concrete
For a sunroom with a masonry thermal wall, use 0.30 m2 of south glazing for each m2 of living space floor area
Have a ventilation system for summer months
If overhead glass is used in a sunroom, use
heat reflecting glass and or shading systems in the overhead areas

14. Insulation
Thermal insulation is the reduction of heat transfer between objects in thermal contact or in range of radiative influence
Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials
Thermal insulation provides a region of insulation in which thermal conduction is reduced or thermal radiation is reflected rather than absorbed by the lower-temperature body

15. Special glazing systems
Insulated glazing more commonly known as double glazing (or double-pane, and increasingly triple glazing/pane)
are double or triple glass window panes separated by an air or other gas filled space to heat transfer across a part of the building envelope

16. Preventing heat from entering the interior (heat gain prevention)
Passive cooling
Passive cooling is a building design approach that focuses on heat gain control and heat dissipation in a building in order to improve the indoor thermal comfort
Preventing heat from entering the interior (heat gain prevention)
Removing heat from the building (natural cooling).

17. Passive cooling
Solar control
A properly designed shading system can effectively contribute to minimizing the solar heat gains
Shading both transparent and opaque surfaces of the building envelope will minimize the amount of solar radiation that induces overheating in both indoor spaces and building’s structure
The heat gain captured through the windows and envelope will be reduced

18. Window coverings
Window coverings are material used to cover a window to manage sunlight
Curtains / Drapes
Window blinds
Venetian blinds: Wood, Faux Wood, Vinyl, Aluminum
Mini blinds
Shutters
Window Shades, including:
Roman & Folding Shades
Roller Shades
Solar screen

19. Window coverings

20. Passive cooling
A solar chimney or thermal chimney
A simple description of a solar chimney is that of a vertical shaft using solar energy to enhance the natural stack ventilation through a building
Is a way of improving the natural ventilation of buildings by using convection of air heated by passive solar energy

21. Passive cooling
Sunrooms can also be designed to perform this function
With the connecting lower vents to the living space open along with windows on the north side, air is drawn through the living space to be exhausted through the sunroom upper vents

22. Passive solar lighting
Passive solar lighting techniques enhance taking advantage of natural illumination for interiors, and so reduce reliance on artificial lighting systems
This can be achieved by careful building design, orientation, and placement of window sections to collect light
The use of reflecting surfaces to admit daylight into the interior of a building
Window sections should be adequately sized, and to avoid over-illumination can be shielded with a brise soleil, awnings, well placed trees, glass coatings, and other passive devices

23. Existing brick walls often have adequate thermal mass
Opportunities for improving or adding passive solar design features when renovating an existing building
Existing brick walls often have adequate thermal mass
Insulate external walls, ensure that thermal mass is balanced by increased solar access, and design openings and convective flow paths to ensure that additional solar gains are distributed effectively
Renovation

24. Increase existing insulation levels and insulate any previously uninsulated ceilings and walls (and floors in cool climates) while they are exposed or during re-cladding or re-roofing.
Design additions to allow passive solar access and facilitate movement of passive heat gains to other parts of the house
Renovation
Use high performance windows and glazing for all new windows and doors
Replace poorly performing windows where possible
Relocate poorly orientated or oversized windows and increase the size of solar exposed south windows
Implement dark external floor finishes

25. And more…
Seal existing windows and external doors, and replace warped or poorly fitted doors
Double glaze windows to reduce winter heat loss
Renovation
Create airlocks at entrances in cool and cold climates
Reorientate as much of the living space as possible to the south side
South-facing bedrooms can become living rooms
Add doors and walls to create zones with similar heating needs
Consider adding a sunroom to maximize solar gains in cool climates

26. Solar passive solutions compatible with existent and historic buildings architecture
Direct solar gains
In summer is possible to use internal movable insulation, ensuring air circulation between this device and the window

27. Thermal mass wall behind a window (Trombe wall)
Solar passive solutions compatible with existent and historic buildings architecture
Thermal mass wall behind a window (Trombe wall)
The integration is possible in existing windows or doors that are not usually opened, preserving existing materials and outside appearance

28. Solar passive solutions compatible with existent and historic buildings architecture
Attached sunspace

29. Solar passive solutions compatible with existent and historic buildings architecture
Convective loop
The thermosyphon effect transfers the heated air in the channel again to the indoor space by an upper vent
During the night is necessary to insulate the windows and close the openings

30. Thank You