The outer enclosing structure in the system of ventilation of residential high-rise building

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The outer enclosing structure in the system of ventilation of residential high-rise building

Dviborodchin R.D.

Annotation

THE OUTER ENCLOSING STRUCTURE IN THE SYSTEM OF VENTILATION OF RESIDENTIAL HIGH-RISE BUILDING

Dviborodchin R.D.

Vladimir state University named after Alexander Grigorievich and Nikolai Grigorievich Stoletovs.

Problematic issues of creating a favorable microclimate parameters of the premises of residential buildings arise in connection with inefficient work of systems of natural ventilation, which is poorly compatible with contemporary designs sealed Windows of glass and a number of indicators do not meet the criteria for energy efficient buildings. The article presents the analysis of the results of field studies of ventilation systems and indoor climate of two 10-storey residential buildings, which showed that the actual air exchange in the premises of apartments at different fixed positions of the valves of glass was only part of the requested values according to the norms (up to 34-46 %). There have been numerous instances of the occurrence of reverse thrust channel windbloom, falling on their surface condensation and mould growth on the reveals of the window openings. Findings of research show that regardless of the state of thermal protection and environmental friendliness of construction materials used multistory residential building equipped with a traditional system of natural ventilation can not meet the requirements of energy-efficient or "healthy" types of buildings. Confirmed the need for extensive use of a special intake valves (aeromate Windows, wall valves), providing a regulated flow of fresh air into living rooms and preventing Saudi rollover thrust in the exhaust channels. With the same purpose, it is recommended to use external fencing structures with ventilated layers allows you utilize - ment the heat of the outgoing air, and other constructive solutions related to the creation of "breathing - ing" the wall.

Keywords: exterior building envelope, natural ventilation system, air exchange, energy-efficient buildings.

Introduction

Use in mass construction of residential buildings of translucent structures with a high tightness of the window of the porch, polymeric building elements and finishing materials increased relative humidity and decreased air quality in the premises, adverse temperature and humidity conditions of cladding, the appearance of wet spots and mildew on their inner surfaces. These problems are relevant not only for our country but for the foreign countries with developed economies. There was even a special term characterizing the state of the internal environment of civil buildings: healthy buildings, "sick house syndrome".

As you know, energy-efficient buildings should be different minimum consumption of energy to operate and comfortable microclimate parameters of the premises, and "healthy" - to meet the increased environmental requirements. Thus, for the first and second types of buildings a significant impact on the formation of climate and environmental condition of the internal air environment should provide natural ventilation system and related functional ability of the enclosure to provide adequate ventilation of the premises.

The formation of the desired ventilation parameters and thermal regime in residential buildings is a complex task, since these parameters are largely influenced by the performance of the heating system, architectural-planning and constructive decisions of buildings thermotechnical indicators of cladding, especially the maintenance of apartments by tenants. In most European countries due to lower air exchange of the premises due to the increase in tightness of outer enclosures, including structures of glass, have been widely used special devices and systems for air flow (aeromate Windows, wall valves, systems supply and exhaust mechanical ventilation).

In our country studies, developed standards for the consideration of the influence on indoor climate and ventilation system a sealed glass constructions, and in recent years, the manufacturing began the production of aromatov, wall valves. However, it should be noted that these special devices have not found wide application in the practice of design and construction, and the existing system of regulatory documents in General, does not take into account the whole complex of influences on microclimate and air exchange in the premises.

The purpose of the study. Stimulating factor in ensuring a more rapid transition to the implementation of special devices and other technical decisions on the regulation of air flow, is the accumulation of experience of field studies of residential buildings and a more complete assessment of the negative impact the existing system of natural ventilation of these buildings on the microclimate of premises.

To assess this influence in February and March 2016 in the city of Vladimir were conducted insitu study of two residential 10-storey buildings on a series of 125, operated for several years [1].

The research material

The layered construction of the outer walls of the said buildings consists of an inner layer of solid sand-lime brick, middle layer of foam layer of the hollow silica brick and an outer layer of ceramic brick core. The Windows are made of triple-pane Windows, attic buildings cool (Fig. 1).

Fig. 1. Residential building on a series of 125

Fig. 2. Built extension arms windbloom

In buildings with functioning natural ventilation system with supply air through the open sash Windows, and exhaust air from kitchens and bathrooms through the holes in the air handling units factory fabricated, with the teams backbone and PE - reponse channels. Experience in construction shows, and the results of the field surveys confirm that the installation of such units permitted violations of the technological process of Assembly (not sufficient tightness of their butt joints of cement-sandy solution, to the exhaust hole unblock can enter the channels, another group of flats). ventilation building intake valve

According to instrumental measurements, the actual air exchange in the premises of the apartments was only part of the required values for the standards (for example, for a 2-bedroom flats with the installation of the flap position of the Windows on the micro-ventilation of this part has not exceeded 34 %, with the opening sash of the window until it stops on the horizontal axis - 46 %). These indicators of ventilation were recorded under favorable conditions ventilation: tenants, one of the main exhaust channel at the same time requested to open the sash Windows, alternately in each of two positions for a long time (a few hours). It can be assumed that in everyday practice the operation of the ventilation system of the event on the organization of the flow of air tenants is almost non-existent.

Instrumental examinations showed the presence of reverse thrust in the exhaust channels. Even further extension of the height of the extension arms of ventilation 1.5 m, made by contractor for additional design decision, not prevented this negative effect (Fig. 2). It was also established that:

* backdraft occurred while a weak inflow of air through the sash Windows, prompting the cold, heavier air to fall through the holes of the extension arms windbloom through the ventilation channels, blocking them and thereby the mechanism of the thermal head;

* the process of reverse thrust intensified under the action of strong winds;

* the number of flats recorded the temperature of the surfaces of ventilation units below the dew point temperature, which caused increased wet spots;

* condensation and mold seen on certain sections of the exterior walls, including the window jambs;

* visual inspection of the lower part of the facades of buildings (subject to good visibility) fold the larger pieces of glass have been closed or set to on the micro-ventilation.

The operation of the system of natural ventilation was influenced by other adverse factors: the lack of dense vestibule entrance doors in building and apartment from the staircase, which creates conditions for the spread of contaminated air from the stairwell and Elevator shafts in dwelling; poor air circulation in the apartments from the supply to the suction openings (no openings in the lower edges of the doors of rooms and bathrooms in all apartments surveyed, blocking exhaust vents periodically working umbrellas gas stoves in the kitchen and fans in the bathrooms in some apartments).

The results of field studies and their discussion

The research results indicate that due to a lack of effective system of natural ventilation and formed as a result of unfavorable microclimate parameters of the premises of the apartments surveyed high-rise buildings, in contrast to the energy-efficient and "healthy" types of buildings, regardless of the state of thermal protection and environmental friendliness of construction materials used have signs of the syndrome of "sick" buildings. In this type of building violated one of the main functions of energy efficient and healthy buildings - a comfortable indoor climate, which confirms the urgent need for the use of technology and the search for architectural design solutions outdoor enclosures to ensure the delivery of optimal volume of inlet ventilation air and reducing energy costs for its heating in the cold season with a minimum expenditure of material resources.

The data of instrumental measurements of the indoor climate of the apartments also confirm that, first, the natural ventilation system provided in the projects of multi-storey buildings, which are not compatible with the system vysokoaromatichnyj plastic Windows, and secondly that the quality of such technical means necessary to use a special intake valves (aeromancy, wall valves), providing a regulated flow of fresh air into living rooms and preventing the overturning thrust in the exhaust channels. The large-scale application of these devices is of particular relevance in the climatic conditions of our country with extensive areas with a long heating period, forcing tenants to conserve thermal energy is not always to keep the window sash ajar.

Modern inlet valves are automatic flow control of air, noise insertion. However, the short operating experience of aromatov in the climatic conditions of the Penza region revealed, however, a certain disadvantage of these devices under adverse climatic conditions and high relative humidity areas, they may be partially clogged with frost and be covered with ice. The design features of wall inlet valves provide available inspection and cleaning of the elements during operation. The introduction of these valves in the local practice of design and construction of high-rise buildings is extremely slow, because of sufficient complexity of the installation in external wall structures and a certain inertia of thinking of professional designers.

As mentioned the architectural and design solutions can be used known construction of cladding with a ventilated layer allowing to recover energy from the outgoing air, as well as others, including innovative solutions, for example associated with the creation of the so-called breathing walls.

One of the models "breathing" walls, based on the economizer effect to its capillary-porous structure, and methods of evaluation of the resulting energy saving effect is considered in [2]. The concept of this model is that in the process of heating cold air infiltrados the heat flux moving in the opposite direction from the heated space, the last receives a certain volume relative to the pre-heated ventilation air, which reduces the amount of its income through traditional injection hole by the same amount. Energy-saving effect of this model is the amount of thermal energy spent on heating of this difference in the volume of air to room temperature.

Reference list

1. Coast A.M. Building materials and envelope constructions of buildings of high thermal efficiency / V.A. Shore [and others]. - Penza: PGAS, 2014. - 180s.

2. Coast A.M. energy-saving Effect in the premise with natural ventilation in terms of air infiltration through exterior wall / Coastal A.M. [et al.]/ / Regional architecture and construction. - 2013. - № 3. - P. 140-144.

3. Levchuk I.F., Naumov A.L. Adjustable ventilation of residential buildings]. - 2004. - No. 5. - URL: http:/www.osnova/od.ua/library/vent-info24.php (date 11.01.2015).

4. Heating and ventilation of residential buildings. Handbook to SNiP 2.08.01-89. Residential building 4. Ventilation. - 2008-2013. - URL: http:/ normativa.ru/content/view/459/24/1/4/ (accessed 9.01.2015).

5. TR]4-2004. Technical advice on air exchange in apartments of multi-storey residential building // tabunshchikov Yu. a. [et al.]. - URL: http://www.gosthelp.ru/text/TRAVOKA 42004 Texnicheskiere.html (date: 10.01.2015).

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