Absorber
Absorber
Absorber
C. Density of Occupation will not only influence air temperature and humidity by
virtue of the heat and moisture contributed to the environment by the occupants,
but also will strongly influence the subjective concepts of freshness and
stuffiness. As our standards of thermal comfort become more sophisticated, a
thermally comfortable environment will not be acceptable unless it is
accompanied by a quality of freshness. Although it is generally recognized that
freshness is related to coolness, absence of unpleasant odors, slight air
movement, and a psychologically desirable feeling of change, and that
stuffiness is partly defined by a degree of hotness, the presence of unpleasant
odors, and the absence of air movement, little scientific information has been
collected on either of these comfort factors.
D. Activity of the Occupants may involve muscular activity, which will increase
the metabolic rate and therefore the body will produce more heat. This additional
heat must be dissipated by the body at an increased rate, so that thermal
neutrality is immediately restored. Accordingly, the comfort zone for persons
engaged in heavy physical work is different from that required for office workers.
2. Give examples of the implementation of external sun shading devices, 1 (one) for
horizontal sun shading and 1 (one) for vertical sun shading. The examples should be
presented in sketches and explanations.
External Solar shading is a form of solar control that can be used to optimise the
amount of solar heat gain and visible light that is admitted into a building.
Advantages:
• Control the amount of radiation entering the building, Providing protection from the
sun’s ultraviolet rays
• the most efficient form of solar protection from the point of view of heat control since the
heat radiation can be completely blocked if necessary
• managing visual environment
• protecting the openings from atmospheric agent
• providing a sculptured skin for buildings
• Enhancing indoor comfort, stimulating productivity
• Creating a cool shade, avoiding the need to reduce temperatures of overheated rooms
and buildings
• Reducing the amount of energy required for lighting, by optimizing the transmission of
free natural daylight
Disadvantages:
• Interference with interior daylighting and natural ventilation. Furthermore, precautions
must be taken to ensure that the shading device itself does not become unnecessarily hot,
thereby assisting the transmission of heat by direct conduction to the wall or convection
to the air surrounding the window opening
• Primarily useful for east and west exposures to improve the insulation value of glass in
winter months by acting as a windbreaker.
• Best to blocking sunlight from west, east, and north.
• Restricts view, but good for occupant’s privacy.
• Require less cleaning than horizontal devices.
• Create a critical horizontal shadow angle beyond which total shading occurs.
• Constant airflow.
b. Ovehangs louver horizontal sun shading system
• To shade a window during hot summer months, but allow sunlight to shine through a
window in the winter, to help warm a building.
• The overhangs have a simple concept and easy installation procedure, considered to be
efficient in energy saving in building heating and cooling energy consumption.
• Best to blocking sunlight from west, east, and south to cut out high angle sun.
• The louvers parallel to the wall have the advantage of permitting air circulation near the
façade.
• Snow, wind, or rain load is small, not trapped.
• Require more cleaning than vertical shading.
3. Solar or sun is an energy that is used in several technologies. Give 2 (two) technologies
that used solar or sun as the primary sources and explain each technology. Present them
in sketches and explanations
Both solar water heating systems and solar photovoltaic (PV) systems involve
collector panels, however, they are different technologies. Solar water heating
systems use radiation from the sun to generate heat for water, whereas PV
systems produce electricity. Solar thermal systems convert 60 percent to 70
percent of the sun's energy into heat, while high-end photovoltaics top out at
around 24 percent efficiency. Because heating it accounts for 25 percent to 30
percent of the average home's energy use, a solar water heater can make a
sizable dent in the utility bill.
Solar water heating systems can either rely on electric pumps to circulate water
(active) or rely on thermodynamics (passive). Active solar water heating
systems are more common in residential and commercial use. Passive solar water
heating systems are typically less expensive, but they are also less efficient.
Solar hot water systems typically last for around 20 years, and some systems will
work for even longer. In addition to the monetary benefits, installing solar hot
water reduces your use of greenhouse gas producing fossil fuels, making it a good
choice for the environment, too. A solar hot water system is also usually better
for the environment than an electric water heater, because the electricity you
buy from your utility was likely generated from coal or natural gas. With solar hot
water, you can be certain that you’re using a zero-emissions renewable
resource.
4. What are the differences between reflection, refraction, and diffraction phenomena in the
nature of light? Present them in sketches and explanations.
• Reflection: The throwing back by a body or surface of light, heat, or sound without
absorbing it. which occurs when light strikes a polished surface and is reflected away
from the surface in such a way that the angle of incidence is equal to the angle of
reflection. Example : Reflection of light in mirror
• Refraction: The change in direction of a wave passing from one medium to another
caused by its change in speed. which occurs when light passes from one transparent or
translucent medium to another. In other words, the light appears to bend slightly as it
enters the second medium.Example: Looking through a glass jar will make an object look
smaller and slightly lifted.
• Diffraction: The process of light bending around an obstacle or spreading out after it
moves through a small space. which light bends slightly around corners. For example, if
we place an opaque object between a light source and a screen, then the light will bend
slightly around the object, resulting in the projection of a shadow that is smaller than
might be expected. Example: Light passing through a narrow opening in the blinds,
causing bright and dark shadows and patterns to fall across the floor.
5. There are various types of luminaire or armature: direct, semi-direct, diffuse, direct-
indirect, semi-indirect, and indirect luminaire. Choose 3 (three) and explain each of the
luminaire features and applications. Present them in sketches and explanations.
a. Direct: Practically all of the light is directed downward, resulting in a low vertical
surface illumination. Direct luminaires are normally used for individually controlled
task lighting, in combination with a general background lighting system.
Intent: Create areas of high luminance on the floor with dark areas in between
Quality: Beam spreads from 30° or lower downwards.
Use: To design a high contrast space. Suitable to be used a task lighting (such as
spotlight)
b. Diffuse: The diffuse system provides light approximately equally in all directions.
The distance between the luminaire and the ceiling should be sufficient to avoid
excessive ceiling brightness.
Intent: To create a stimulating, high brightness interior.
Quality: Light emitted in several directions.
Use: Reduced shadow and contrast. A high brightness interior. Suitable to be used a
general lighting (such as chandelier)
c. Semi Indirect: Similar to the indirect system, except that the shade is translucent,
thus allowing about one-third of the light to fall directly into the room. Nevertheless,
the ceiling remains the main radiating source.
Intent: Light emitted in only upward and downward direction. 60% to 90% of light is
upwards [14].
Quality: Moderate contrast in the space.
Use: To balance uplight and downlight, creating a space of moderate contrast. Used
in a space requiring less direct light and glare. Suitable to be used as a general and
accent lighting.