Tuesday 31 March 2015

is solar heating appropriate to heat the water in the school project?

Solar heating is where the sun is used to heat water for a building. This includes large panels with an array of copper pipes and black painted steel plates positioned similarly to a solar panel on a roof.
Painting the steel plates a black matt colour mean it will conduct the suns heat as much as possible, which in turn will heat the water. The piping system is then encased in a transparent box to create a 'greenhouse' effect trapping the heat in to the panel. This sort of system can heat up water very quick providing it is being hit by beams of light. the panels efficiency can reach around 50%, but can drop to nearly 0% when there is a lot of cloud cover, and wind that can cool the panel down.
In addition to the unreliability of solar heating, maintenance is also an issue. It is a regular occurrence for the pipes to expand and retract, meaning leaks appear at joints regularly. The expansion of the water inside the pipes as it heats up creates additional pressure to the system than can also cause damage. In some cases, even soldered joints can become loose. All of this maintenance costs a lot of money as only skilled plumbers will be able to fix the joints. Furthermore, leaks can cause lots problems in a number of ways to a building and to a site. A reputable manufacture should be searched and used when considering the installation of solar heating panels.
Another problem is the space the solar thermal heating takes up. These usually have to be positioned on a roof, which is where solar panels and a green roof could be. it must be carefully thought about which system is going to be the most sustainable for the school.
Finally, due to the size of the school, the demand for water could be quite high, especially considering there is a sports hall with showers. It is unlikely solar heating could meet the demands of hot water a school may need, so it would not be the only source of hot water the school would have.
Because of these reasons, it is unlikely solar heating would be a suitable solution to heating water

Saturday 28 March 2015

How could I use glazing or a conservatory to use the sun to heat my school?

Conservatories are often overlooked in the design of a sustainable building, when in fact they can be the best, most efficient way of heating a building. Conservatories, if positioned correctly, take the thermal energy from the sun and absorb it through glazing. It can be argued that glass is not the best material for holding in heat, but conservatories are usually a secondary structure built on the exterior of a property, so the heat already in the house is not lost. however, heat gained from the glazing can then pass through into the house and warm the house up.
The best orientation for a conservatory is south, so that it gets most of the sun. This could effect the entire orientation of the building. Similar to solar panels, this would only work during the day, and when there is good, direct beams of sun. It is also effected by shading, so if there are any buildings or trees in the way of the sun, the conservatory becomes useless.
As the school is a large multi-story building, a conservatory is not suitable, and it is more suitable for a domestic property. However, glazing could be an appropriate alternative for the school project. If the south facing wall was fully glazed, the amount of thermal energy it could create could heat the entire school, providing the ventilation was set up correctly.
A glazed wall would also allow a lot of light into the building, which typically reaches 6-7 meters into the building. this could also save a lot of energy on lighting.
One issue with a glazed wall is that usually, when it is sunny, it is generally hot. This could mean the glazing is heating a building that needs to be cooled rather than heated. A solution to this is to open the windows and let the warm air back out.
Also, when it is cloudy and the sun is not directly shining on the glazing, a negative effect can occur and heat can be lost through the glazing. this makes the idea of a glazed wall unreliable. It should certainly not be used as a prime source of heat and light in a on the school, but would be a good contributor to heating and lighting the school sustainably.

Is it possible to use hydro power on the school project?

Hydro power is a great way of using water to give us power. As well as being very efficient, huge quantities of power can be created providing the conditions are right. This usually means a large reservoir or water source situated at a point relatively high above the ground, such as a hill, or large dam which gets a continuous feed of water from rainfall or rivers and streams.
Hydro power works when the potential energy stored in the water is converted to kinetic energy. This involves the water flowing at high speed turning a turbine. It is important the pressure of which the water hits the turbine is monitored and adjusted to get the most efficiency. The average efficiency of a hydro generator is about 37%.
When calculating the pressure release of water by the water source, it can be estimated that for every 10m in height difference between the water source and the turbine, the pressure is 1 bar. It is recommended that the minimum height difference is 20m or more to make the hydro generator worth using. The turbine then turns a generator that produces the electricity. The generator should be positioned as close to the water source as possible to keep the friction caused by the plastic pipe on the water to a minimum, so the most pressure is retrieved.
Unfortunately, the site the school is going to be built on is rather flat. Although the river Trent is not far away, there is no way of building a dam or raising the water level. This means there is no potential energy to start the process of hydro power, meaning a hydro generator wouldn't produce any electricity. In addition, the electrical demands of the school are very high, and a hydro power system wouldn't be any where near sustainable and powerful enough to power a school. For these reasons, it is not deemed a useful system to add to the school.


How can solar panels be used efficiently on my school project?

Solar panels are a way of transferring the suns solar energy into electrical energy. Although there are many different types, these most commonly come in Monocrystaline modules made up of 36 separate circuits, wired in a parallel.
The amount of power produced by a solar panel is incredibly dependent on the weather. When beams of light, known as direct radiation means the solar panel can produce up to 80% more power than if the weather is cloudy, meaning the solar panel only receives diffuse radiation. Typically it should be expected for the efficiency of a solar panel to be around 14% -16%,
Shading is a serious factor when considering the installation of solar panels. Anything from a building to an Arial cable casting a shadow on a solar panel can cause it to nearly completely stop working. This is because of the electrical circuit in each module. Each module has 2 circuits running in parallel, which splits the module up into 2. If a shadow is cast upon one of these sides, it provides immense resistance and breaks the circuit, deeming the entire half panel useless. This can happen to both sides of a panel, even with the smallest of shadows. To prevent this from happening the solar panels must be positioned so that they never encounter shading. This means a detailed site investigation must be done around the site to make sure there are no building, trees or any other objects shade the panels. Furthermore, there are many different types of software that can produce solar models, with information on where the sun will go all through the year, and where it will shade. Solar calculators can be used to see how efficient the location of the solar panel is.
The hotter a solar panel gets, the lower its efficiency gets. This is because as the electrical mechanism gets warmer, so does the resistance, resulting in the currant increasing and the voltage decreasing which decreases the power output. The most effective panels are offset from the rood so there is air circulation around the whole panel. However, this means wind can get underneath and could blow the panel away. Typically, a meter of plain roof is left to help prevent this from happening, with extra strong fixings used.
Due to the sun rising in the east and setting in the west, for a static panel, it is most efficient to face it towards the south, at an angle similar to that of an average roof, which is about 35 degrees. However, panels can be put of a mechanical system that moves each panel in accordance with the sun. At the CAT centre in Wales, tests are currently being done to see if it is more efficient to have a static panel, a panel that follows the suns path, a panel that moves from east to west, and a panel that points to where it is lightest in the sky. It would be valuable to see what the results are to see if it can be incorporated within the school project.
An issue with solar panels is space. The best place for them to be positioned is on a roof, as it is out the way. However, this can complicate plans to have a green roof, or use solar thermal water heating, as well as having a roof garden. Calculations and research must be done to work out which system would have the most sustainable and positive effect for the school.
A school, especially a large multi-storey school like this given design, will use a lot of electricity. There is likely to be hundreds of computers, TVs, lights, speakers, kitchen utilities and other appliances a typical school has. A typical computer runs at about 850watts, which would need a whole solar panel that runs at 1.75kw (peak) to power it. In addition, solar panels only work when the sun is out, so at night especially another source of electricity must be used.
Because of the small power output of a solar panel, and the large usage of computers, it is in-practicable to consider using solar panels as the main electricity supply, as it would not cope with the schools usage. However, it is certainly a possibility to use solar panels to power the lighting, and maybe some appliances in the school.


Would Biomass be a suitable sustainable solution to heat my schools water?

Biomass is an alternative way, other than gas or electricity (created by fossil fuels), to heat up water in a building. This water can be used for a number of different uses such as heating and hot water outlets. The process involves burning either timber logs, wood chips or wood pellets at a fast rate to heat water, which can in turn be pumped into a building.
For biomass boilers to work as a large scale solution to sustainable energy, it must be exercised properly. This would require a very controlled reforestation program. This has a number of implications such as destroying animals habitats and planting on grazing land for livestock. As a result, it is predicted the country would have to eat less meat, and effectively become vegetarian, which I unfortunately had to experience at my field trip to the CAT centre in Wales.
In terms of efficiency, pellets are the best biomass fuel, with an average efficiency of approximately 90%, although some manufactures are offering a 96% guarantee. This is due to the wood being finely ground and then compressed meaning there is no air inside the pellet, maximising the fuel/volume ratio.Wood chips also have a very high efficiency, followed by logs, of which have an approximately 80% efficiency. When talking about efficiency, it is important to understand it only takes into account the efficiency of the biomass heater, and not the rest of the pipework ect. Also there are different grades of log, chip and pellet. The dryer the wood, and less bark it contains usually offerers the best quality fuel.
One issue with biomass heaters is the immense amount of fuel they use. For a large school, with an appropriately sized mediocre boiler, it would take approximately 2 tonnes of fuel to start the heater up, and then a continues feed is needed. Although this provides massive space problems, it also means someone must be employed specifically to feed the boiler. Despite there being hopper systems in place for pellet or wood chip boilers, these hoppers would need to be refilled quite regularly. When thinking from an economic point of view, the regular refill, fuel, maintenance, and wages to run a boiler must be considered. Also from a safety point of view, regular large lorry's delivering fuel could be considered a safety hazard with a large number of school children in and around the school. In addition, an area for the lorry delivery, store of fuel and boiler must be considered when designing the school grounds, which could be put to better use.
Another implication with biomass boilers is that they produce lots of dangerous gases. These must be extracted and deposited high into the air so they don't come into contact with humans. This must be taken very seriously, as dangerous gases around a school could be very harmful to its students.
For a biomass boiler of a size to heat a large school, it must be of a particular size. This size of boiler is very noisy and would have to be encased in a sound proof building so that it did not disturb the students who occupy the school. A separate building, or fire proofed room must also be built to store the fuel, in case there was a fire which would obviously be a serious disaster if the fuel got caught.
Taking into account the considerations and implications listed above, I do not think it is suitable for the school to have a biomass boiler, as they are too noisy, and require to much fuel to run.

All information was sourced from a guide at the CAT centre in Wales on 25/03/15.

Saturday 3 May 2014

Task 7 - Urban spaces - Victoria Square, Birmingham

As I'm from Birmingham,  thought I would choose an urban area I have spent a lot of time in, back at home. Victoria square is a very popular and busy urban space situated in the heart of Birmingham. It has many similarities with the Market Square of Nottingham, such as being situated next to the council house, and having a water feature. However, I think the design of Victoria Square makes it a much more inviting space.
 As shown in my first sketch, at the heart of Victoria Square is a large, 2 tired water fountain, where water from the upper tier falls down stairs to the bottom tier. Both pools have a water statue, which either sits in the flowing water or projects water into the air. Just the sound of running water creates a peaceful effect, which is nice in a busy city when trying to escape some where for lunch. Surrounding the water fountain is low, thick wall which is often used for seating, weather or not it is busy. The purpose of this urban area seams to be junction for people walking through, as there are many entrances and exits to this area, all leading to different parts of the city. I think this because there is very little purposely built seating, suggesting it was never in the design , or brief for this area to be used as a seating area. Maybe it should have been put in the brief, as many people sit in the area, and its almost always occupied.
My second sketch is a view from the top tier, looking upon the fountain. Many, large concrete sphere balls create an edge around the area, following the shape of the fountain wall. Although these could be there for an aesthetic impact, I believe they may serve as fancy bollards preventing drivers from going in that direction. They too could even be an informal type of seating, and together with the spheres, and the fountain wall, maybe the client brief was a seating area, but the architect has tried to disguise the seating so that its not formal.   

Finally I tried to draw the whole of the area so the layout of the area can be properly seen. Other pointers why I think the brief for this area is for 'passers by' and not for people to linger is the stairs. Both stair cases are very large, plenty enough room for the rush hour pedestrians commuting to and from work. The size of this area also means events, and markets such as the very famous German market can be held here, and can accommodate for a lot of people. Its now also viable that the design of the urban space is very symmetrical, with equal stairs either side of the fountain. then, protruding from the fountain are different coloured, yellow, floor bricks, creating an effect that nearly draws you closer to the fountain. The surroundings of this Urban space are also very impressive, with the famous Town hall, and council house facing the space. To conclude for this urban space, I again think that this urban space is very successful as it is used by a lot of people, for multiple reasons, its a flexible, attractive space in an urban landscape.

Task 7 - Urban spaces - Castle gate, Nottingham

Castle Gate, Nottingham is also home to an urban space, with much more unique properties than many other spaces. The site sits on the footstep of the towering walls of the historic Nottingham castle. Here there is the famous statue of Robin hood, with several plaques and information boards spread across the area, mainly for the benefit of tourists who visit the site all year round. This is what I chose to sketch first. Because of this statue, the access to historic information, and the castle, its hard to argue with the fact this area was designed for tourists to visit, to walk around and find out about the history of the area. Furthermore, only a 20 second walk down the road is the 'trip to Jerusalem' which claims to be the oldest 'inn' in England. This too is a tourist magnet and brings an influx of people to the area.
 My second sketch looks at the layout of the area with plenty of grass, which is well kept, where, especially in the summer months people can sit and have lunch whilst visiting this historic area. The way these paths are mapped, in relation to the information plaques, and the robin hood statue further support the claim the brief is to design an area for tourists to learn about the history of the area. Large trees offer shade, as the area gets a lot of sun during the spring and summer making it ideal for parents too take there children there too. this area is only a 5 minuet walk from market square, the centre of Nottingham, but it is a very quite area, with little traffic pedestrians.
 Finally, I sketched the site as if you where walking up to it. In the foreground you have the grass area, and in the back ground you have the large tunnels under the walls of the castle. Like the castle, the surrounding buildings are all old, or follow old, traditional styles such as Tudor. Even the Old Trip To Jerusalem was built in 1189. The lack of modern buildings makes the urban space very unusual, and it feels very separate from the rest of the city. I think the council have tried to limit the redevelopments in the area to keep this atmosphere, as plays a massive role in the phenomenology of the area. There is no seating in the area, similarly to the Victoria Square, Birmingham, so it is assumed the area was not designed for people to stay. To conclude, I think the area is another successful urban space, and the client brief has been met.