Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 165 (2016) 891 – 897 15th International scientific conference “Underground Urbanisation as a Prerequisite for Sustainable Development” Improvement of a common approach to the design of passive ventilated apartments Željko Jakšić a, , Milan Trivunić a, Vera Murgul b* b a University of Novi Sad, Trg Dositeja Obradovića 5, Novi Sad, 21000, Serbia Peter the Great Saint-Petersburg Polytechnic University, Polytechnicheskaya, 29, Saint-Petersburg, 195251, Russia Abstract Ventilation presents a major impact on the performances of the building, which are covered by the Energy efficiency Regulations Good (natural) ventilation provides a good quality of indoor air which means a satisfactory level of humidity, temperature and circulation Consequently, designer’s primar goal is to harmonize this mentioned elements This issue imposes as a problem at the facilities that represent multifamily housing, especially due to a fact that is quite complex area, not just black and white In the article has been presented an approach both of analysing relevant elements influencing in a sustainable process of natural ventilation and sustainable concept of apartments functional organization through the layouts sketches © 2016 2016Published The Authors Published by Elsevier Ltd © by Elsevier Ltd This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the 15th International scientific conference “Underground Peer-review under scientific committee of the 15th International scientific conference “Underground Urbanisation as a Urbanisation as aresponsibility Prerequisite of forthe Sustainable Development Prerequisite for Sustainable Development Keywords: investment, internal rate of return; Introduction Organization of an apartment produces certain effects Many of them derives from the time in which they arise So, it could be completely natural to expect that new time brings new possibilities and breakthroughs in the habitation area One of them is the Regulations on energy efficiency of buildings which provides many of crucial elements for good being people in closed space and within them the issue of natural ventilation and passive cooling * Corresponding author Tel.: +7-950-0101931 E-mail address: october6@list.ru 1877-7058 © 2016 Published by Elsevier Ltd This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the 15th International scientific conference “Underground Urbanisation as a Prerequisite for Sustainable Development doi:10.1016/j.proeng.2016.11.789 892 Željko Jakšić et al / Procedia Engineering 165 (2016) 891 – 897 This artical deals with the probleme of proveading good air quoality and its adequat temperature at multistory buildins apartments Passive ventilation and cooling Air can be kept fresh with high ventilation rates, either using natural ventilation such as operable windows and skylights, or active systems such as HVAC fans and ducts Clean air can be achieved by filtering air, by flushing spaces with fresh outside air, and by not contaminating the air with impurities from the building, such as volatile organic compounds from paints or materials Natural ventilation can still be an option even in hot climates, particularly in hot dry climates Fig A courtyard fountain in the Alhamba cools air before it entres the building If air is too stale or is polluted, it can make pople uncomfortable, unproductive, unhappy, and sick Fresh air requires a certain percentage of outside air circulating into spaces 2.1 Passive ventilation If we know what the floor plan is for home space we can easily diagram how we think the air might flow through our home if we began opening windows As a rule, air does not cut across hard angles so the diagram should look similar to the one below with “flowing” air movements Wind hitting an open window at a 45° angle of incidence would have a coefficient of effectiveness of roughly 0.4, while wind hitting an open window directly at a 90° angle would have a coefficient of roughly 0.8 When placing ventilation openings, it needs to place both air inlets and air outlets; often they not have the same area Fig “Flowing” air movements [1] 893 Željko Jakšić et al / Procedia Engineering 165 (2016) 891 – 897 To measure the effectiveness of ventilation strategies, it can measure both the volume and speed of the airflow The volume of the airflow is important because it dictates the rate at which stale air can be replaced by fresh air, and determines how much heat the space gains or losses as a result Passive ventilation uses doors, windows, vents, louvers and other openings to bring fresh air into a home and let stale air out The size and placement of these openings can be used to guide air into and through a home Passive ventilation can only work if air has clear, uninterrupted pathways through a home In general, windows should be larger on one side of the home than the other in order to encourage air flow Fig To encourage cool air flow, it'll need larger windows opening to the breeze and smaller, higher windows on the walls on the opposite side of the house The appropriate ventilation options for a home will depend on the climate and microclimate of the habitat area, and what prevailing breezes there are As a rule of thumb, the area of windows, doors and other vents that can be opened up to the outside should be at least 5% of the floor area for each living space - and more for high-use areas a) b) c) d) e) Fig The most common method of natural ventilation is to open a window, where could be ventilated by short-term and long-term The ref is short-term and stronger ventilation, fully opening all the windows at regular intervals, for example every 3-4 hours In this way all the air will be altered for 4-8 minutes Speed air change depends on the number of holes, their position and openness (example a, eventually b) Some features will provide low-level background movement of air between a home's interior and exterior This is often called air infiltration, and can cause draughts and heat loss in winter Passive stack ventilation Passive stack ventilation system using ducts from the ceiling or walls of rooms to terminals on the roof which operate by a combination of the natural stack effect Stack ventilation takes advantage of this effect by constructing openings in the building envelope high at a substantial height, allowing the warm air to escape The negative pressure at the top of the building draws in colder, denser outside air through openings low in the building 894 Željko Jakšić et al / Procedia Engineering 165 (2016) 891 – 897 Fig Some examples of passive stack ventilation in practice Naturally, this effect is fairly weak, but it can be concentrated through the use of a stack Longer stacks will typically increase airflow (chimney effect) Controlled stack ventilation can allow for passive cooling in the summer with some benefits over mechanical ventilation including low maintenance and operating cost, minimal or no energy costs, and typically lower construction costs in new buildings, as passive stack ventilation is designed similarly to mechanical ventilation without the mechanical components 2.2 Passive cooling The demands on energy-efficient cannot cause a deterioration of thermal comfort in the room “Thermal comfort is a condition in which a person feels that his body is in a sustainable balance of heat that does not feel or feelings of warmth or cold.” [2] The basic parameters of thermal comfort are following: human energy expenditure, heat conduction resistance of clothing, air temperature, average temperature of radiation, speed of air flow and relative humidity of air Where cooling is required, windows or other openings on upper levels can be opened to let warm air escape In winter, well-designed passive ventilation refreshes the air in a home without creating draughts or letting out too much heat Layout and baseline energy usage 3.1 Building layouts Building configuration and orientation are strategies that architects historically have employed to increase the energy efficiency of buildings „O“ „A“ „I“ Fig Volume of building as crucial factor toward the good EE practice[3] 895 Željko Jakšić et al / Procedia Engineering 165 (2016) 891 – 897 Figure shows nine building layouts inspired by Steven Holl's pamphlet Alphabetical City [3] All the buildings were designed with the same envelope construction: metal panel walls, green tinted insulated windows, and singleply roof with R-15 insulation The selected site for this study was San Francisco, CA With no sustainable strategy employed, the most energy efficient layout is type “O” (BO), the large floor plate rectangular building, with an annual energy performance of 273 MJ/m2 (mega joules per meters squared) The small perimeter to floor area ratio makes it an efficient building to heat and cool with a traditional HVAC system Type “O” is not an ideal building type to use with many sustainable strategies Although the type “I” bar building (BI) does not appear to be energy efficient in this initial study, it does possess qualities that enable it to benefit from sustainable strategies such as access to natural light and a large South elevation that can employ solar shading to control heat gain Therefore, this study will focus on the bar building as the baseline building type to compare the benefits of various sustainable strategies Solar orientation has a substantial impact on energy usage for directional buildings This is most dramatic when applied to the type “I” Bar Building (BI) (Table 1) Table Baseline energy usage ENERGY USE [MJ/m2] COOLING [MJ/m2] HEATING [MJ/m2] LIGHTING [MJ/m2] (BO) Type 'O' Developer Box 10 HVAC Zones 318.29 203.85 8.63 105.81 (BI) Type 'I' Baseline Bar Building HVAC Zones, Facing North & South 369.18 244.42 18.95 105.81 (BI-NS) Type 'I' Bar Building Facing East and West 417.07 292.46 18.80 105.81 3.2 Main vertical communication position and apartments orientation A lot of research deals with the influence of the mass of the building and the organization of its functional elements such as staircases, facade envelope or terraces and loggias However, the choice of solutions is not so easy to make The solutions are a product of optimization impact of several important factors, some of them stands out as more important In this case it comes to passive ventilation in the regime of energy efficiency Fig Influence of the building concept 896 Željko Jakšić et al / Procedia Engineering 165 (2016) 891 – 897 Discussion and suggestions Air flows from high pressure to low pressure When wind encounters an obstruction, it will flow around the object and continue moving in the same direction It is important to note that if wind is blocked by a landform or surrounding building, the wind is not stopped, but rather just deflected Wind speed varies with height and terrain As elevation increases, so does wind speed As terrain becomes rougher, the rate at which wind speed increases slows This means that the wind speed in an open, rural, environment will increase with height much more quickly than the wind speed in a dense urban center Fig Wind does not reach full speed until a certain height off the ground; this height depends on the local obstructions Sites with high levels of acoustic noise, such as near heavy traffic zones, may be less suitable for natural ventilation because large openings in the building envelope can make it difficult to block outside noise Passive stack ventilation system has both benefits as well as drawbacks Benefits are following: allows for building cooling and ventilation with lower maintenance and operating costs than mechanical systems, minimal operational noise; require no additional energy, stacks supplemented by active flow control use less energy than equivalent mechanical systems and etc Drawbacks are following: due to reliance on natural forces, over ventilation and under ventilation can occur frequently; proper design and flow control are necessary to maintain adequate ventilation rates; ventilation can be inadequate on upper floors of larger buildings, trapping heat and reducing air quality Suggestions To improve upon the poor ventilation opportunities afforded by standard double loaded apartment blocks, we looked to split the apartment’s blocks which are closer together and allow ventilation to penetrate deep into the building volume Fig 10 Natural ventialtion design process Željko Jakšić et al / Procedia Engineering 165 (2016) 891 – 897 Offsetting these pairs of apartment units allows fresh air to pass straight through individual apartments when desired, or to funnel around to the side when each volume is shut tight To provide occupants with a high quality of internal environment, each apartment layout has been carefully considered to maximize access to natural ventilation Fig 11 Naturally ventilated apartment layout Fig 12 An interesting but much more expensive solution Conclusion If a home is designed for passive ventilation, all need to is open and close windows, doors or other vents as needed to reduce the temperature and improve the quality of the air you're breathing It is better to plan good ventilation together with a well-insulated house, than rely on leaks and draughts which cannot be controlled when it needs to and won't necessarily ventilate the right places Massing and orientation are important design factors to consider for passive cooling Consider these factors early in the design so that the building layout and building orientation can all be optimized for passive comfort References [1] G Z Brown, M DeKay, Sun, Wind & Light, Architectural Design Strategies, Second edition,USA, 2000 [2] P Pauter, J Panovec, Energy efficiency project according new and existing buildings, Project, co-funded by the European Union, the Russian Federation and the Republic of Finland, Oulu University of Applied Sciences [3] Ph Lou, Designing Net-Zero Buildings with Energy Plus, LEED AP, 2009 [4] S Holl: Pamphlet Architecture #5, The Alphabetical City, Princeton Architectural Press, 1980 897 ... house The appropriate ventilation options for a home will depend on the climate and microclimate of the habitat area, and what prevailing breezes there are As a rule of thumb, the area of windows,... position and apartments orientation A lot of research deals with the influence of the mass of the building and the organization of its functional elements such as staircases, facade envelope or terraces... sustainable strategies such as access to natural light and a large South elevation that can employ solar shading to control heat gain Therefore, this study will focus on the bar building as the baseline