Green Studio Handbook - Part 4

Chapter 4 4.2 Stack Ventilation

STACK VENTILATION is a passive cooling strategy which relies on TWO basic principles. - As air warms up, it becomes less dense and rises. - Fresh ambient air replaces the air that has risen.

STACK VENTILATION is a natural convection system which creates its own air current where warm air is evacuated through a high point , and cooler outdoor air is brought in at a lower level .

IN ORDER for the system to function properly, the difference between indoor and outdoor air temperature needs to be at least 1.7 degrees Celsius. A GREATER temperature difference can provide more effective air circulation and cooling.

Increasing the HEIGHT of a stack is one way to achieve a greater temperature difference. The higher the stack, the greater the vertical stratification of temperatures.

Another way to increase the temperature difference between entering and exiting air is to use solar energy to heat the air . Stacks are glazed with a translucent material so that solar radiation heats the air in the stack, causing an increase in airflow within the building.

Building Research Establishment Building In the BRE building the stacks are given greater height than the rest of the building, providing an architectural feature that highlights the significance of these devices to the functioning of the building.

Key Architectural Issues - A stack needs to generate a large temperature difference between exhaust air and incoming air . This can be done in several ways, including increasing stack height . A typical stack will provide effective ventilation for areas within the lower half of its total height.

Stacks may be integrated within the design or left exposed .

Implementation Considerations - Stacks provide more air movement at lower levels . Modular and separated stacks can address this problem, but an abundance of stacks is costly and requires more openings, which may not be possible for a variety of reasons; security, location, adjacencies, etc.

Vertical stacks may need to be integrated with HVAC and structural systems to ensure effective utilization of space.

Outside air is flushed through the building to provide cooling, allowing anything in the air to be introduced to the building, including undesired aspects such as noise. Therefore, careful attention should be paid to nearby noise sources.

Design Procedure 1. Establish a workable stack height for the project. 2. Size the stack openings which will in turn, define the system’s performance.

3. Estimate the cooling capacity of the stack ventilation system on the basis of stack height and stack to floor area ratio. 4. Adjust stack openings and/or height as necessary to obtain desired cooling capacity.

Hood River County Library, Oregon

Albany County Airport, New York

Chapter 4 4.6 Earth Sheltering

DEFINITION Photovoltaic: Systems that produce electricity through the direct conversion of incident solar radiation. - Provides direct output that can be stored in a battery or converted to power.

TYPES OF PV MODULES Thin- film (amorphous panels): Crystalline. Cover entire panel. No glass. Lower efficiency & cheaper than Crystalline panels. Crystalline (single and multi) panels : Circles assembled in a frame. More efficient & expensive than amorphous panels.

INSTALLATION Add on System: Stand Alone System Grid Connected System No Grid Require battery storage More space Use local electrical grid Store excess generation capacity Require less equipment Space saving ADD ON SYSTEM BUILDING INTEGRATED SYSTEM

INSTALLATION BUILDING INTEGRATED PHOTOVOLTAICS (BIPV) MULTIFUNCTIONAL USES: - PV Shading Devices - Cladding Materials. Lillis Business School. University of Oregon, Eugen, Oregon. Fossil Ridge High School.

To determine efficiency percentages with varying tilt angle and orientation. INSTALLATION PV ORIENTATION & TILT Best orientation: south Best tilt angle: equal to your latitude. Example: Kuwait = latitude 29 ° TILT ANGLE OPTIMIZED PERFORMANCE 1.0 on the chart is the most efficient.

INSTALLATION Location : Roof of a building, on ground, on façade. Monocrystalline silicon roof modules. Sanyo HIT Double bifacial solar panels generate power from both sides of the panel, providing most of the electricity for the house.

DESIGN PROCEDURE SIZING A PV SYSTEM: To find the required area of PV modules: A= C/3.3 C: desired PV system output in W (start with providing a general target of 1000W) For 8% efficiency: divide the above area by 2 For 12% efficiency: divide the above area by 3 For 16% efficiency: divide the above area by 4 Note: for a stand alone system keep storage space in mind.

Design Considerations Orientation. Space. Integration with the building design. Maintenance and regular cleaning access to the panels. Energy Saving Efficiency Cost

INTERNATIONAL EXAMPLE Curtain wall of the Xicui Entertainment Complex in Beijing. In Beijing, World's Largest LED Display Uses Solar Power Location: Beijing Architect: Simone Giostra

Location: Tsinghua University, Beijing Architect: Mario Cucinella The Sino-Italian Ecological and Energy-Efficient Building (SIEEB) INTERNATIONAL EXAMPLE

The new campus was constructed meeting all the ministry requirements for insulation and energy consumption. Photovoltaic panels were introduced to provide power for lighting in the central areas of the building. The expensive price of photovoltaic panels made it hard for more of them to exist through out the building. A plan of a self- sufficient electricity roof for the swimming pool area was intended, yet not accomplished because of the expensive cost of the panels. LOCAL EXAMPLE GUST CAMPUS

ADVANCEMENTS : NANO SOLAR Cost efficient solar power. Based on Copper- Indium- Gallium- Selenide (CIGS) semiconductor material Flexible, ultra thin polycrystalline film ** These quantum NANO dot solar cells currently have an efficiency around 20% Nano Vent-Skin - CO2 Filtering Solar Micro-turbines! Nano film strip

ADVANCEMENTS : NANO SOLAR Nano Vent-Skin that sheathes structures in a shimmering solar weave studded with micro-turbines. Nano Vent-Skin: Micro-Turbines running on solar power to absorb CO2!

ADVANCEMENTS : NANO SOLAR The Solar Wave Pavilion Covered with flexible photovoltaic cells. The electrical energy produced can also be stored in the form of hydrogen gas, which could be manufactured from the rainwater that is captured off the roof of the structure.

By Nasser Aldubaibi Ali Alkazemi

Wind turbines produce energy from an ever-renewable resource, the wind. Wind energy is an indirect implementation of solar energy, in other words the change of air temperature in different levels of land creates wind due to the rise of hot air and drawn of cooler air to replace it. The main idea behind the turbine is to transform the kinetic energy into electricity.

The wind speed determines the amount of energy available while the turbine size determines how much of that resource harvested.

the wind turbine consists of the following: a rotor generator (or alternator) mounted on a frame tail tower wiring system balance Inverters batteries

The most common wind turbine is the horizontal upwind turbines it has two or three blades, the swept area is the area of the circle created by the turning blades ( the larger the swept area the greater the amount of power produced). The frame of the turbine holds the rotor and generator and supports the tail. The tail keeps the turbine facing into the wind.

Wind turbines are sized based upon power output and they are used for: Charging batteries for recreational vehicles and sailboats. Pumping water Generate electricity for residential and small commercial applications.

Although it might be tempting to mount a turbine on a rooftop it is not recommended to do so due to the vibrations from the turbine which can cause structural problems as well as irritate building occupants and users. The newer turbines produce less noise than earlier ones (no noisier than an average refrigerator).

Towers are a necessary part of a wind system because the higher the tower the more power a turbine can produce (more economical).

The site has a good/acceptable wind resource The site is at least 1 acre (4046 m 2 ) Local zoning allows wind turbines A wind turbine could produce a sizable amount of electricity used by the building It represents an acceptable life-cycle investment for the client The site is in a remote location that doesn’t have an access to the electric grid

There are two types of wind turbine systems: Grid-connected: it uses an inverter that converts direct current (DC) generator output to alternating current (AC) to make it compatible with the utility grid and appliances. Stand-alone (or hybrid): its not connected to the utility grid and can provide power in remote locations and it requires batteries to store energy to be used when there is no wind.

The grid-connected system allows power to be used in a building or sold to the utility company and batteries are not required. The system is good choice when: The site has an average annual wind speed of at least 10mph. Utility supplied electricity is expensive. Connecting a wind system to the utility grid is allowed. There is a reason for the sale of excess electric generation and/or purchase to the wind turbine.

In stand-alone system an inverter is required to convert DC output to alternating current (AC). It combines wind and photovoltaic technologies to produce energy. The system is a good choice when: The site is in an area with average annual wind speed of 9 mph A grid connection is unavailable Independence from purchased energy resources is an intent The intent is to use renewable energy resource

To start designing an architect has to follow a certain procedure research land use issues including set back requirements, maximum allowable tower height and so on. Calculate the wind resources: wind speed and direction are changing all the time it can change during the day and seasonally. Evaluating the distribution of wind speed throughout the year is the best way to estimate an average wind speed.

3. Calculate building energy requirements and estimates of consumptions during the year will be useful in design 4. Use equations associated with the turbine size to determine the performance of it such as (AEO = 0.01328 D 2 V 3 ) (D=rotor diameter V=wind speed AEO=energy output) 5. Locate the turbine and establish the tower height. The bottom of the rotor blades should be at least 30ft.

Wind turbines can reduce use of electricity generated from non-renewable resources. It produces electricity at lower cost than a new power plant using any other fuel source. It can lower a residential electric bill by 50 to 90%.

Green Studio Handbook - Part 4

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Green Studio Handbook - Part 4

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