| Peculiarities of ecological designing |  |
| Ecologization - Peoples Eco-Life Project | |
| Wednesday, 30 September 2009 09:09 | |
PECULIARITIES OF ECOLOGICAL DEGIGNING(thesis of the report, information from the web-page) Tetyana Ernst, architect, Candidate of architecture science Nowadays “environmental friendly behaviour” and “environmental oriented planning” should include a number of steps with regard to improve overall situation on a planet, securing health of each individual and it has to foresee thoughtful and thrifty utilization of energy resources.
Environmentally reasonable design foresees creating general ecological concept of planning, constructing and using a building. It means:
Effectiveness and ecological compatibility of constructions are defined by many factors:
When choosing construction ground the following factors should be considered:
Architectural project of the building is important component and includes actions on energy saving:
From the middle of 1970-s most of the European countries increased norms of heating protection into 2—3.5 times. Nowadays this process is ongoing: requirements to heat isolating materials constantly increase, heat penetration norms become stricter for single buildings as well as for constructions in general. When choosing building materials, big attention should be paid to the energy consumption necessary to produce these materials. For instance, if energy to produce heat isolating materials, their transporting and processing on the build ground exceeds the level of energy we save by using these materials for the building, then such a building will not be eco-friendly even if it does not require any heating. Therefore, when calculating energy utility of materials the attention should be paid not only to their coefficient of heat penetration but also to the energy consumption necessary to turn raw material into specific building element according to the time of it’s use in the building and saving energy while using it at this time and also energy for this element utilization. Apart from this it is necessary to choose such materials that during production, building and utilization do not throw out into the environment harmful to the people toxic gas, dissolvent, radiation etc. When choosing energy beneficial constructions and materials it is necessary to pay attention to the following:
When planning engineering equipment of the building it is necessary to consider the following:
Together with active use of sun energy it is also possible to use the passive one by means of appropriate architectural planning solution. Thus with the help of so called “buffer zones” there is a possibility to warm up the fresh air (for example winter garden) and to supply heated fresh air to the rest of functional zones. Apart from heat isolation of construction, parts of the building have power to heat accumulation is of great importance in comfort creation, that is a power of different materials to take, keep and give away heat energy. Materials that have power to take heat and give it away with one hour difference balance temperature of the inner environment. Wide roof can be very simple and cheap sun protection. Ledge of the roof protects inner rooms from overheating with the summer sun, but allows low level winter sun to get through deeply inside. Rain water savings should not be neglected. Provisions of fresh water are also very limited in the world. Rain water from roofs can be collected and used in farming (agriculture) for watering or in toilet barrels. Active use of energy resources which have a power to renew, happens due to special engineering systems using energy of inexhaustible energy sources (sun, wind, soil) and relatively inexhaustible (timber, plants, waste):
Passive use of energy resources, that have ability to renew, happens due to proper dimensional planning. That is:
Passive use of the sun energy is based on supplying inside the building as much of the sun warmth as possible which is used to heat the whole building and keeping it as long as possible in the solid part of the building. This is possible with the help of the correct windows location and transparent parts of the building, which is aimed to “catch” almost horizontal (winter) sun rays.
Earlier heat isolation was only preventive means for ruining part of the construction and buildings. But nowadays people begin to understand that constant and increasing utilization of natural resources brings to their deficit in the globe. Proper heat insulation creates comfort inside the building (when you can lean against the wall and not to jump away from it “burning yourself” with a cold, there are no draughts in winter, in spring it does not drip to the floor and there are no stains on wallpaper. Properly done heat insulation protects parts of the building from damages created from moisture condensation on the walls and windows (fungus, cracks that appear from significant temperature drop). Such heat insulation is expensive, but in a few years it is worth due to cost savings for the heating. By means of emission reduction increasing of heat insulation contributes greatly to environmental protection. Heat insulation can be done on the main and fence constructions, inside and outside the building. But for sure it is definitely, energetically and ecologically beneficial to put heat insulation on the outer side of the fence construction. It allows us to avoid “heat bridges” and shift “dewpoint” from main constructions in to the heat insulation sphere that increases time of building usage. Quality level of winter heat insulation depends on the following factors: building shape — part of heat insulated outer surfaces to the total capacity of the building; heat insulation itself — quality of the heat insulation materials and coefficient level of heat; and finally — heat conductivity of fugue, joints and seams meaning changing warm air into the cold because of the low impermeability of windows and doors and also window ventilation (in contrast to controlled ventilation). Such, heat insulation is expensive and in a few years it pays back entirely due to cost savings on heating. Through decreased emission, increased heat insulation contributes greatly to the environmental protection — it helps air cleaning, that we inhale and decreases greenhouse effect on a planet. Properly done heat insulation protects parts of the building from damages created from moisture condensation on the walls and windows (fungus, cracks that appear from significant temperature drop). Apart from winter heat insulation there is also summer one, which is oriented on building protection from overheating by direct sun rays penetration inside the building and on its external not insulate surfaces and it can influence the inner comfort climate of the building. Using special lugs, oriel windows, cornices and other building elements that could give enough shadow for light sensitive parts are well known and effective rooms protection from overheating from direct sun rays hit through light transmission (windows and glass surfaces). But if the shape of the building does not allow, it is possible to use special sun protection elements like: shutters, blinds, marquis and also special sun protective glass. In this case important to note that using external protective elements is much more effective compare to the inner one. Because blinds or curtains that are inside the room after warming up gives all the heat inside, that brings it to overheating and quality level of life in it drops. It is important to use special protection from the sun if glass surface of the building exceed 30% of the whole place. Warming up building spaces process, via direct sun rays hitting non transparent parts of the building is decreasing according to the mass increase of these parts. In this case solid parts of the building should be on the inner side from the outer layer of heat insulation. It is possible to improve summer climate of the premises, airing them in the morning and at night, when air outside is not warm yet, but in this case better not to open windows in the evening. Apart from heat insulation, heat accumulation is very important, for the comfortable and calm atmosphere inside the building. Ability to accumulate heat it is an ability of different materials to keep and give away heat energy. Ability to accumulate heat is important when comfortable atmosphere is created: materials that have ability to take heat and give it away with one hour difference influence, balancing the inner temperature of the room. Ability of walls, floors and ceilings to accumulate heat is very important when warming up or cooling off the building. In winter walls and floors materials can (through the transparent parts of the building) perceive the heat, that is emitted by he sun and give it back to the building after the sunset, which is also cost saving for the central heating. The order how layers from different materials are arranged inside the thick wall (especially layer of heat insulation) is very important for heat preservation inside the building. Depending on the building function it is necessary to choose where to put insulation layer, closer to inner or outer side of the wall. Insulation layer which is closer to outer side of the wall increases the ability of the material to accumulate heat, but it delays warming up the room. But then warmed room does not loose its heat for a long time even after the heating is off. On the other hand, inner insulating layer allows warming up the room very quickly, as well as cooling it off. During the engineering planning of the building a possibility of using renewable energies actively should be considered. It is important to choose ecological heating systems and fuel and to ensure equal distribution of radiators or heat emitting planes inside the buildings. There are heating systems with high (up to 90 °C) and with the low (from 25 °C up to 55 °C) temperature of heat carrier. Hot water heating is best adapted for heating big distance (central heating of one city area). Its disadvantages are consumption a huge amount of energy on the way to the final destination points. Low temperature water heating system is more economic compare to the previous system and it is first of all for warming up small buildings. Meanwhile heat carrier in the boiler house warms up to 40—70 °C therefore looses less heat on the way to apartment’s central heating device. When using heat pumps for heating and cooling off, the most effective system to use is with low temperature of heat carrier. Also worth mentioning that heat pump allows not only ecologically heat buildings in winter, but also cool it off in the summer (that is very important nowadays, keeping in mind constant global warming). Heating pump that works to cool off the building is healthy alternative to air conditioners, which are widely used in Ukraine for cooling buildings off, as we know are very unhealthy. Taking a chill out from the ground in the summer, heating pump inflates heat into the ground “keeping” it there in winter by the time when heat is needed inside the building. And “cold walls” ensure creation inside the building during he summer pleasant and cool climate without negative effect that we can have from air conditioners. There are a lot of heating surfaces, from ordinary cast-iron radiators which heats the building by warming up the air in it and all the walls which are also surfaces that emit heat or cold. Existing heating systems are divided into convecting and radiating. Convecting heat (which is passed through the movement of the air and often through this movement it creates draughts) does not creates comfort feeling compare to emitting heat. Heat from the sun, stove, fire-place or wall is perceived by the upper level of human skin and it reminds the most natural source of heat — sun. Emitted heat, even with low temperatures inside the building, gives a feeling of healthy climate. People perceive with their body not only the temperature of the air but also temperature of the surfaces of solid materials that surround the room: walls, floors, equipment etc. Cold surface people feel like a draught, and it is harmful for health. Research demonstrated that when temperature inside the room is +24 °C, and temperature of walls surface is much lower, people individually perceive room temperature on the level +20 °C. At the same time when walls are warm and temperature in the room is +18 °C, people also individually feel +20 °C. Lower temperature that people inhale has better influence than the high one. Besides heat emitting walls or floors do not have dust, therefore do not pollute the room because of dust combustion. Surfaces that emit heat, energetically and ecologically profitable compare to ordinary radiators. They require more heat emitting planes, but with such heating system they have quite low temperature surfaces (24—45 °C) therefore heat consumption is less when moving heat carriers from the warming source to the emitting surface. Such surfaces have very good influence on human health and create comfortable climate inside the room. Building surfaces that emit heat are heating of the floor and walls. Warm air goes up and after cooling off moves down. In such a way our ordinary heating systems are unhealthy. They warm up the air up to 24 °C on the top, where human’s head always is, and while the air moves down it cools off up to 16—18 °C. That is why feet are freezing and at the same time head is overheated, lungs inhale overheated air. Taking onto the consideration the fact that lungs better adapted to inhale air with the temperature 18 °C, it is clear that the best heating system for the human being is when floors and walls are warmed up. When the floor and walls are warmed up to +24 °C, warm air gradually moving up, cools off and on the head level temperature 18 °C, and under the ceiling only 16 °C. Now let’s have look at the problem of supplying fresh air inside the building, so called ventilation problem. Good ventilation is extremely important from the point of energy resources savings and improvement of ecological conditions on the Earth. The main aim of ventilation resists to heating task. Heating of the buildings operates better in completely closed and isolated from environment houses. At the same time the main function of ventilation is to bring fresh air from outside. Human being can live a couple of weeks without food, a couple of days without water, it cannot live 5 minutes without air and it confirms vital necessity of the fresh air inside the closed buildings at its best Recently ventilation becomes more controlled process during which the cold or often polluted or even humid or dry air gets into the building and the air is cleaned, warmed up, humidified or dried. Therefore ventilation works not “against” heating (increasing so heat energy consumption), but together with it. There are too many steps between entirely natural and entirely controlled ventilation. For instance, from the ecological point of view of climate warming, it is important to pay attention to the fact that in winter when we leave pilot window opened or leave open for “airing” modern plastic energy saving window — we heat the street. In this case it will be very stupid to build heat insulating building. Things won with the help of heat insulating we have lost it at the same time through pilot window. Besides small pilot window cannot filter all the old air from the room and change it to the new and fresh one. As we know warm air is lighter. Therefore opened pilot window brings to the fact that most of the warm air (which produced by radiator under the window) is going outside, but through the same pilot window not enough fresh air gets inside the room. During such constant “ventilation” walls and other big heat storages cool down, and create unpleasant air for people, and water drops move closer to the inner surface of the wall and helps to create fungus on the walls. Hence, when we want to have fresh air inside the building, it is necessary to tern off the heating and open widely all the windows. Through large outages of widely opened windows, within 5 minutes the air inside the room will change and then we can close windows and turn on again the heating. This procedure should be repeated from two to four times a day and it is enough to support healthy climate. Recently ventilation becomes more and more controlled process when not just a cold and often polluted or very humid or dry air gets inside the building, but air is cleaned, warmed up (due to heat recuperation) and humidified or dried. Therefore ventilation is working not “against” heating (increasing heat energy consumption), but together with us. Controlled ventilation creates conditions, when warm “used” air is not just released through the window into atmosphere, but it goes through special equipment and so called “recuperation” (that is heat exchanger) gives its heat into the air. Therefore, first of all warm air does not get into the air and it does not join climate warming, secondly: fresh air gets into the building previously warmed up that ensures lack of unpleasant processes for people: draughts.
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