AD 572 TECHNOLOGIES 2 Erabu Joel Wallace Level 5 Student BA (Hons) Architecture Duncan Baker-Brown 22nd August 2016
AD 572 TECHNOLOGIES 2
Erabu, Joel Wallace
De La Warr Pavilion, Ventilation Table of Contents Page # 1. Introduction of Existing Ventilation Systems 2. Introduction of Ventilation Issues in Cafeteria 3. Design of Pivoting Windows for Cafeteria 4. Tackling Issue of Strong Wind at Facade 5. Tacking Issue of Glaring Sunlight in Winter 6. Summary of Project
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PERSONAL PROPOSAL EXISTING SYSTEMS
Theres a couple of issues concerning natural ventilation; -During the summer the room gets overcrowded and exceeds human thetmal comfort. -Doors and windows lack ventilation at their tops hence making retantion of warm air in the room easier.
MAIN AREAS The mojority of this building uses natural ventilation. These areas include the cafe on 1st floor, the corridors around it and the staircase. Ventilation is done by opening or closing the doors and windows of these areas.
Photo of sea side part of the buiding AUDITORIUM The ventilation in this space was recently renovated including a swegon unit system that cost about ÂŁ400,000 to replace the dated system that was put in place in 1935. The new system consists of two vents that act as ingress and egress points for cooled air and warm air respectively.
The new swegon unit for the auditorium is state of the art ventilation for this kind of space and is an unprecedented move for a building with a lot of heritage. The swegon system not only cools air but also filters the air to ensure the space is suppied with quality air. Another huge advantage of this system is that it saves cost on energy especially in the event where warm air is required, the heat from the warm air being taken out is captured and used to warm the air being taken in. This is seen especially in the winter times when room temperature goes below human thermal comfort and warm air is required in the space. Auditorium
Swegon Unit System
GALLERY 1. Ventilation in this space is through vents situated at either sides of the floor. On one side air warm air is sucked in and taken to an egress at the carpark, while on the other side cool air is brought into the space to keep it comfortable for humans.
The ventilation system for gallery 1 works fine but there is one major flaw, the fact that the ingress - egress vents are actually found at the car park. The issue here is that the car fumes get sucked up into the system and this air gets chaneled into the gallery and is a health risk. Fresh Air Inlet Vents
OTHER SPACES On the ground floor by the entrance there are ventsas seen in the picture. This is the same with the shop on ground floor. The vents let in warm air during the winter to warm up the room to human thermal comfort. Apart from these vents, the circulation of air in this room is controlled naturally by opening and closing doors.
Warm Air Egress Points Like the cafe space, the ground floor space has natural ventilation as well but with circular vents at the top of the main entrance and in the shop to let in warm air during cold days.
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PROJECT FOCUS; CAFETERIA VENTILATION CURRENT VENTILATION; Currently the cafetria has natural ventilation. This is done by opening up two windows and one door that let in and let out air of the room. The windows here are double glazed which help in control of heat thus good for ventilation. Problems faced during cafe ventilation; Just two windows open;The current natural ventilation does not work well during the summer especially as when more people use the space, more heat is created in the room and the opening of two windows does not ventilate the room well enough. Double-glazed windows + non opening windows. Most of the windows in the space do not open, and the fact that they are double glazed means that more heat is retained especially in summer and this creates an uncomfortable interior space. More windows need to be opened to create better ventilation to work with the double glazed windows. Strong winds from sea. This is a major issue for this building as the winds hinder a lot of activities that would be done at the roof terrace and the ground below. This is perhaps one major reason the architects decided to keep the windows closed.
People using space. Not only the people that create heat in the space, but also the food they consume as well as their gadgets they bring with them.
Sunlight Coming In. Another cause of too much is the sun coming into the space, heating it up with no proper ventilation system in place.
Limited air passage. The windows as seen in the picture and graphic are limited to which can be opened. This is a major issue as the warm air stays kept in and no fresh air brought in.
SOLUTION 1. Opening the windows. Opening the windows is a great idea because firstly this is a natural way of ventilating and this cuts down on costs of operation. This method is also energy efficient asnatural wind is used rather than electricty or other fuels.
Initial planning included survey of the exististing structure that included the new swegon unit. The proposal here is to connect a ventilation system for the cafe with the existing swegon unit so as to ventilate this space as well.
2. Opening the roof/ vents. Creating a vent/ vents in the roof would be useful as this would take out used up air from the space. This also works well with the natural ventilation as it comlpetes the air cycle from inlet to outlet as we know that warm air rises. The air taken out of the room however has to go through a heat exchanger.
How the system will work: -During the warmer times, the fans at the top of the cafe shall ventilate the space as one side takes out warm air, while the other chanels in cooler air. In this period the system shall not use the swegon control. -However during the winter the system shall automatically synchronise with the swegon unit to let in warm air to balance room air. -An added benefit to this system is that wind power shall be generated from this throughout the year and this energy shall support the swegon unit thus cutting down on costs of electricity as well as heat caused by a lot of wiring.
3. Heat exchange. The air taken up by the vent then goes through a heat exchange system that traps the heat and then the heat is stored for the cooler months. Heat thats captured is usually stored with objects that have heavy mass e.g rocks that are placed under the ground. 4. Wind barrier One final thing to consider for this system is the strong winds from sea that actually destroy glass due to alkalinity. A wind barrier would be a good solution as it also creates more performance space.
DESIGN SOLUTION; PIVOTING WINDOW + CEILING VENT
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Window Solution My initial solution for the cafe space involved looking through some already exixsting window designs that would suit the space, hence my choice of the revolving/ double face window. Figures 1,2 & 3 are diffrent iterations I came across on the internet, while 4-9 are windows I experienced first hand from Grand Parade.
Fig 1
Fig 2
Fig 3
Figure 4-6 The pictures show the windows of Brighton University Arts building at Dorset Place, near Grand Parade. The size of the panels is almost 8feet, which is just about the size of the De La Warr Pavilion windows. The window panels are held at bottom and top centre by a hinge on which they rotate about 10- 15 degree either inward or outward depending on the location of the opening handle. The restriction to 15 degrees also a safety precaution incase strong winds attack the glass, the windows wont slam and break. The pivoting windows are easy to operate and also easy to clean as they have two faces. One other great thing about these windows is that actually as you open one window, the pressure on one side is greater than on the other and this causes air to get expelled as cool fresh air flows in, which in itself is a great solution for ventilation.
Fig 4
Fig 5
Fig 6
Fig 7
Fig 8
Fig 9
However, there is one drawback to windows in this area, STRONG WINDS. The winds in this area reach a speed 47mph, and that alone is enough to break all the glaas at the facade. There is a solution to this however, which is to put a temporary barrier at the front of the facade.
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WIND BREAK DESIGN CANOPY BARRIER This is a wind shield made from ultra modern steel, plywood and fibreglass with a purpose of controlling strong winds from directly hitting the facade. The choice for material is reason being that steel and fibre glass combined have high strength and durability and can withstand strong winds.
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10H STRONG WINDS HALTED BY CURVED CANOPY The south westerly winds come to the coast at high speed of between 33mph to 47mph hence the reason for the construction of this temporary pavilion to create some wind turbulance. The turbulance is good in this case because it greatly slows down the wind speed and cold, thus making the area at the facade of the building more usable for performance space.
TURBULANCE As strong wind hits the barrier, the pressure is suddenly brought to a haltand this causes the wind direction to change variably as noted above. The speed comes down and negative pressure is built up, causing some of the wind to curve back.
WIND SHELTERED SPACE About a distance of 10 times the height of the barrier is actually protected from the strong winds. The turbulance caused by the barrier makes the wind skew away from intended direction of flow and creates a curve above the land below.
WIND BREAK When wind encounters a wall, it either goes round the corners or over the top, giving increased speed in those areas because extra air is crowding through. Moreover, wind eddies backwards in the relatively ‘empty’ space on the leeward side, sometimes with as nasty effect for plants situated there as if they had received the direct blast of air. A wind break building/ fence gives better wind protection because it allows enough air through to prevent the eddy space behind, yet breaks the initial force of the blast. [Oxford College of Gardening]
Any obstruction to wind flow, including buildings and trees will produce disturbed air, manifested as wind shear and turbulence, that can significantly effect strength of wind reaching the building. Effects may become more evident in strong winds on the lee side of obstructions. Figure 3 shows some of the effects, which are: flow is disturbed to approximately three to four times the height of the obstruction [h] and 50 h downstream (beyond the scale of Figure 3); a cushion of air with weak eddies extends 2 h to 5 h upwind; wind is accelerated above and leeward of the barrier, the greatest increases in speed being at approximately 2 h to leeward and 2.5 to 4.5 h above the ground;
NEGATIVE PRESSURE AREA At about a distance of 10 times the height of the barrier, the wind direction starts to come back down to ground as the air above it also applies pressure downwards. The point at which the wind starts to curve backwards is known as negative pressure.
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GLARING SUN CONTROL SUMMER SOLSTICE The summer solstice occurs when a planet’s rotational axis, in either northern or southern hemispheres, is most inclined toward the star that it orbits. Earth’s maximum axial tilt toward the Sun is 23° 26′. This happens twice each year (once in each hemisphere), at which times the Sun reaches its highest position in the sky as seen from the north or the south pole. This years summer solstice was Monday 20th June. During summer solstice the building is protected by the overhang as seen in the picture. At this time the sun angle is at 63.5 degrees and this is just stopped by the overhang. The major issue solved by the overhang is the extremely hot summer sun that would greatly affect the ventilation of the building.
Fig 1
Fig 2 WINTER SOLSTICE This takes place on December 21st, and the sun angle will come down to 16.5 degrees. Because this angle is so low, so much sun light is exposed to the building and the overhang is not enough to keep the glaring sun light out. The winter sun however is essential as it brings warmth into the room because the temperatures are usually low at the time.
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Fig 3 SOLUTION; Light Control Film Blind
This light-control film is based on the fact that there is a change in the incident angle of sunlight between summer and winter. The film blocks sunlight in summer by using total reflection but transmits it in winter. Unlike other light-control films, the film can control the transmission of direct sunlight while always allowing people inside to see the view outside the window. Without any inherent changes, the film automatically controls light transmission depending on the season. Light transmission can be controlled simply by attaching the film to an existing window. Therefore, if the film can be efficiently produced, it will save energy by substantially reducing cooling and heating loads.
Figure above shows the basic structure of the developed total-reflection light-control film. The film uses a transparent medium with the front and back surfaces not parallel to each other. For example, when an acrylic material (refractive index n = 1.49) is used as the transparent medium, with the back surface angled at 7°, and light comes from air onto the surface of the medium at an incident angle larger than 60°, the light refracted in the medium is incident on the back surface at an angle larger than the critical angle and total reflection occurs. However, if a transparent film with non-parallel surfaces is used as a window pane, the light from the view outside of the window is refracted and the view looks suspended in air. To prevent this, another film with the same cross-section is layered upside down to the first film.
CREATING VENTS AT TOP FOR AIR EXPULSION Vents at the top of ceiling are important because these take out used up air and keep the air at the room fresh. Currently the building has no such system in place and this causes the air in room to be stuffy and warm. The vent at the top of the kitchen sucks up warm used up air, then does a heat exchange, which heat is then chanelled to the swegon unit for storage and use for colder periods. The used up air is then expelled out of the building
OPENING WINDOWS- CROSS VENTILATION
Opening the windows is the first solution because this works with the natural ventilation of the entire building. Opening the windows at the pivoting angle of 15 degrees also creates a pressure imbalance at both sides causing fresh air to come in as used up air is expelled from the building.
STRONG WIND CONTROL. Strong winds usually attack the south facing facade and this hinders lots of activities here. The spaces both at rooftop and on ground become less inhabitable due to this. The solution is contructing a wind barrier. THERMAL MASS- EXCESSIVE HEAT CONTROL As seen in the graphic, the facade is greatly exposed so sun heat especially during the summer. This heat however is stopped from getting into the building by the overhang. The other heat however is captured by the heavy concrete structure and thus essential in the ventilation process. The pillars at the facade are alos made of concrete and this reduces excessive summer heat from going into the cafe area. The pillars though thin also act as light control.
Natural Ventilation; The major reason for opeing the windows is because this allows for cross ventilation, which is natural ventilation. This method is not only cheap, but also very energy efficient. This methos also maintains most of the original look of the building as only the windows are slightly changed.
STRONG WIND CONTROl 2 The graphic represents wind simulation of this building on CAD. The canopy at the front of the building breaks the wind by creating a turbulance area, thus protecting the windows of the building.
SOLAR CONTROL + THERMAL MASS
SUNLIGHT CONTROL- BLINDS BEHIND WINDOW One major problem this south facing facade faces is glaring sunlight especially in the winter due to the low angle at which the sun comes down. The winter sun however is useful because it brings in warmth, so the best solution would be to control the light coming in and get the warmth. The best solution for this would be a light control film that lets in light at angles that counter the summer sun angle, but let in winter sun with control of amount of light getting in. The light control film does this automatically and works with the natural ventilation system.
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