lectures

lectures.(C)

Ecology, comfort and well-being.

Buildings are similar to our bodies. This image taken from the lecture is a sketch of Francesco Di Giorgio Martini relating a well balanced building (it qualities & characteristics) to the human body. Environmental elements such as temperature, light, wind, water source should be considered and be distributed in balanced proportions, along with the buildings physicality (the form, fabric, mechanical systems, controls etc.)

The human body is adaptable in many environments. Buildings can be viewed similarly as well in that it can host different programs and uses. This sketches also highlights nature, where a lot of modern buildings fail to create a connection (due to factors such as comfort, convenience) relying on high powered machineries to create system of comfort over designing with consideration on existing natural elements.

Concept of thermal comfort.

We are all gaining and shedding heat from our environment, and it affects our comfort. If we gain heat and retain it we get hot, and if we’re not able to retain heat and discharge heat faster, we get cold. Heating means creating flow of heat from inside the body into the environment. Similarly, buildings react the same when it comes to climatic changes. For buildings to resist heating up, we have to avoid direct solar access by creating shades or louvres. Another factor to be considered are the ventilation systems as they aid releasing the heat exiting out of the building. To stop a building from dropping temperature, we need to do the opposite. This is done by increasing the access to solar gains, extract heat from mechanical ventilations and limiting air flows by having increased insulation. Another factor for consideration would be the materiality of the building as surface area increases heat exchange.

Ventilation systems

Current buildings carry mechanically regulated ventilation systems delivered via ducts. Mechanical ventilation systems do circulate air well from such a low cost. However, ducts take up space, cause noise, draughts and temperature variations which can caused illness. Exhaust ventilation depressurize the building in that it retrieves contaminated air in order to let fresh air occupy the building. Exhaust vents are easy to install and does not require huge amounts of space. However, flues can easily get contaminated (dusts, molds, cobwebs, contaminated air). Another type of ventilation is from a supply system. It puts pressure within the building, pushing contaminated air out through vents or openings, with better handle on the exhaust systems. Due to it’s ‘inward’ system, it avoids contaminants from entering in. There are other ways of retaining/gaining heat such as the use of heat exchangers (energy recovery). Overhead delivery supplies air from the ceiling (ducts), which is the same for the exhaust. This type of system tend to be more common in commercial and public buildings due to its capacity (bigger equipment). Subfloor supply system is an alternative to overhead supplies as it has a smaller equipment. The air is introduced from the base level of the building which travel up the levels via vents.

Sound (D)

There are a couple of key factors in measuring light. Luminous intensity (candelas) and Luminous Flux (total power also known as lumens) are the main data that are collected when testing light sources. Illuminance is another important factor which talks about the light source reflecting from a surface. For normal domestic spaces, we normally require between 50 to 500 lux (ie. bedrooms, garages, living spaces etc. In terms of luminous efficacy, daylight is the most efficient light source as it is universal, pollution-free and has numerous effects to our hormonal levels.

While daylight is a great source of energy and of course light, it also gives huge amounts of radiant heat and can be excessive for us. Adequate amount of daylight can be achieved (daylight autonomy) by changing the effects of illumination to our spaces by way of strategic spatial planning (orientation, obstruction, materiality etc.). Examples of how to light source can be done regulate is by the applying mechanisms such as shading, skylights, atrium and reflectors.

Exposure to sound/noise is a continual experience from a conscious context. The distinction between sound and noise can only be defined as per the individuals experience and perception. Sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. Noise is unwanted sound that can be associated with negative experiences (i.e.. Stress) to one’s subjective perception. Sound/Noise is also spatial just like light. Similarly, it can be received directly or indirectly (via sound reflection). As we are binaural, we detect sound distance/location due to the uneven spread of incoming information from the source which is then processed by the brain in a spatial manner.

As stated, Sound is created by vibrations of matter; molecules contracting and retracting via natural factors such as atmospheric/environmental pressure (i.e. temperature). The distance and speed of the sound is dependant on its medium, therefore not constant. Sound travelling from Solid or liquid is much faster than the ones through air. Like light, sound waves dissipate as they go further from the source. When measuring unit of sound (decibels, or db), one must consider the distance from the source and the environment where sound is travelling, factoring key elements such as sound reflection, (surface) absorption and scattering.

Sustainability in building design(E)

What is a sustainable building? This question can be defined in numerous ways/perspectives. Some of the key elements that one may look at in designing a sustainable building could be the Economy of resources. This talks about the natural energy that can be harvested and stored as per the buildings environment; Sources such as solar energy, water harvesting from rain, and local materials that can be used as a component of the building. Another principle that perhaps may contribute to defining what sustainable building is would be its life cycle.

Strategic planning of building phases is just as important as building the structure itself; going over materials, effects and uses of those materials and the possible usage of local resources (pre-building phase), ethical building methodologies (building phase i.e. minimising gas emissions), and the longevity of the building (post-building phase). During the planning stages, one can also consider the possible effects of the building to the user; how structures will influence the habitant’s social connectivity, surrounding conditions and comfort.

Material Ecologies

Materials that are more dense or robust tend to have high thermal conductivity. These thermal conductive materials such as steel or masonry score low in insulation due to their highly dense molecular composition. Materials that are of cellulose type such as foams or fabrics (containing air gaps within) performs well in insulating a building. Strong materials also tend to retain less energy, as an example bricks take a while to heat up and cool down; making it a suitable element to prevent heat from entering a building (thermal mass wall). The duration of time in delaying heat from entering a building depends on the level of thermal mass capability of the protective element (walls/roofs); great thermal mass provides longer thermal lag. Apart from conductivity and energy retention of Materials, another consideration is their potential for physical changes driven by temperature. Thermal expansion occurs when a material is exposed to extreme heat changing its structure. Materials that are high in thermal conductivity tend to have low thermal expansion (bricks, steel, concrete) and binding element such as silicones, foam and rubber score high in expansion.

Buildings are some-what of a living organism. And to be able to survive, it requires energy consumption to run and create a comfortable environment within. As per energy consumption, all of us are still depending on the major energy resources such as crude oil, coal, natural gas, or heavy oils. However, a lot of countries are starting to implement and use renewable energy taken from sustainable resources such as wind (commonly using wind turbines), Water (Hydropower), Earth (Geothermal energy), and Solar energy. There are other unconventional energy sources that are much closer to us such as burning human waste to make steam for turbines to provide energy, same as using waste food that produces methane, which can be transformed into electricity. Out of all the renewable source of energy, the sun is the easiest and most accessible source. Not only that it provides Vitamin D to us, Solar energy can also be harnessed for energy commonly via Photovoltaic panels.

As mentioned from the energy lecture, Water is one of the main sources of renewable energy. Apart from energy, water can also be used to regulate temperature indoors. There are few types of water heating systems that are commonly used in most households; Storage water heater and instantaneous water heater (via heat exchangers). Photovoltaic panel heated water system is another commonly used system where the tank is installed near the panels. Other heating use of water is by putting it through pipes for sub-floor heating. Water is versatile. It all solid, liquid and gas. It has high heat capacity and can almost dissolves anything. Above all, water is an essential element for our survival. In Victoria, we store our natural water into reservoirs, which then treated and transported throughout the aqueducts to our homes. In terms of water exiting our homes, we have two -way system; Stormwater and Sewer mains.

Sustainability Strategy + Analysis (F)

The building industry accounts for half of Australia’s electricity consumption and nearly a quarter for our greenhouse gas emissions. To be able to reduce this, a tally of consideration shall be looked at ranging from minimum compliance to high performance capabilities for the project. One of the first component of building design for sustainability is the façade design. Not only that it is the first visual representation of a building, in most cases it’s also the first element that is directly impacted by the surrounding environment: Wind, Radiation, Rain and so on. There are a few way methods to capitalise the use of the façade to improve the buildings performance. Running environmental simulations helps study a sites existing condition in relation to the design. Results from these simulation can provide direction in terms of approaching the façade design; minimising heat during summer, maximising heat during winter, harnessing heat for energy etc.