Basic on Passive design and Elements of Passive Design

1. Ar. Anand Godson M.Arch (ID)
PASSIVE DESIGN
OBJECTIVES
After completing this unit, the student should be able to
1 Discuss the procedure in passive design
2. Design a house using passive design techniques
KEY WORDS
Direct Gain Thermal Mass Solar Orientation
Overhung Building Envelope Sunshade
'Passive design' is design that takes advantage of the climate to maintain a comfortable
temperature range in the home. Passive design reduces or eliminates the need for auxiliary
heating or cooling
Passive solar design refers to the use of the sun's energy for the heating and cooling of living
spaces. In this approach, the building itself or some element of it takes advantage of
natural energy characteristics in materials and air created by exposure to the sun
DIRECT GAIN
Direct gain is the heat from the sun being collected and contained in an occupied space. This
heat can be retained by the building’s thermal
mass, or can be avoided with reflective
materials.
It is the most common, simple and effective
approach. The basic principle is that sunlight is
admitted into the living spaces, directly through
openings or glazed windows, to heat the walls
and floors and thereby the air inside. The
requirements of a direct gain system are glazed
windows and thermal storage. The glazed
windows are generally located facing south to
receive maximum sunlight during winter (in
northern hemisphere). They are generally double
glazed, with insulating curtains, to reduce heat
loss during night time.

2. Ar. Anand Godson M.Arch (ID)
THERMAL MASS
Thermal mass is the ability of a
material to absorb and store heat
energy. A lot of heat energy is
required to change the
temperature of high density
materials like concrete, bricks
and tiles. They are therefore said
to have high thermal mass. Lightweight materials such as timber have low thermal mass.
SOLAR ORIENTATION
Orientation is the positioning of a building in relation to
seasonal variations in the sun's path as well as prevailing
wind patterns. Good orientation can increase the energy
efficiency of your home, making it more comfortable to live
in and cheaper to run. ... Orientate your home to make best
use of sunlight and winds.
BUILDING ENVELOPE
The building envelope is the physical separator between the
interior and exterior of a building. Components of the
envelope are typically: walls, floors, roofs, fenestrations and
doors. Fenestrations are any opening in the structure: windows,
skylights, clerestories, etc.
SUNSHADE
Shade (shadow), the blocking of sunlight by any object.
Space sunshade, a device for blocking a star's rays in space.
Umbrella, a device for blocking sunlight or rain.

3. Ar. Anand Godson M.Arch (ID)
FIVE ELEMENTS OF PASSIVE SOLAR DESIGN
Elements of passive design:
1.Aperture or collector —the large glass area through which sunlight enters the building
2. Absorber —the dark surface of the storage element that absorbs the solar heat.
3. Thermal mass —the material that stores the absorbed heat. This can be masonry materials
such as concrete, stone, and brick; or a water tank.
4. distribution method —the natural tendency of heat to move from warmer materials to cooler
ones (through conduction, convection, and radiation) until there is no longer a temperature
difference between the two.
5. control mechanism —to regulate the amount of sunlight entering the aperture. This can be roof
overhang to allow more sunlight to enter in the winter, less in the summer.
FACTORS THAT AFFECT THERMAL COMFORT BY ENERGY CONSUMPTION IN
A BUILDING ARE:
(a) landscaping,
(b) ratio of built form to open spaces,
(c) location of water bodies,
(d) orientation,
(e) plan form, and
(f) building envelope and fenestration.

4. Ar. Anand Godson M.Arch (ID)