Calculation of the natural ventilation system of a residential building

Contents

Types of ventilation and purpose

Natural ventilation

Creating an Optimal Production Environment

Objectives and objectives of the course project

Initial data for ventilation system design:

Natural ventilation

Pluses natural vent systems:........................................................... 7 Minuses vent systems:

Scheme of natural ventilation in the apartment (apartment building)

Calculation of air exchange volume of ventilated room

Aerodynamic calculation

Literature:

Introduction

Industrial production processes are accompanied by air pollution of premises with harmful substances, as well as excessive heat released during the operation of mechanisms, heating systems, light sources, from the effects of solar radiation. Harmful impurities in the working area and excess heat have adverse effects on the health of personnel. One of the common and effective ways to protect against adverse factors and maintain air composition within sanitary and hygienic requirements is general room ventilation.

Prolonged exposure to adverse conditions causes stress in the body, which can cause deterioration in well-being and undermine health. In medicine, there is such a concept of "hyperthermia" in which the human body, not being in a state of illness, raises its temperature to 3839 ° C, which is characteristic of high physical activity. And constantly being in conditions of high humidity causes significant harm to health.

There are certain rules governing all the main indicators of microclimate in premises with a constant presence of people. And these standards pay great importance to the air quality that fills this room. For example, according to the SanPiN 2.2.2.54296 optimum microclimate in service premises in cold season have to have the following indicators: air temperature is 2123 wasps, relative humidity is 4060%, the speed of the movement of air no more than 0.1 m/s.

Efficient ventilation allows you to create such parameters of the atmosphere in the room that can provide good health, high performance or a full rest in a ventilated room.

As a result of research by hygienists, air pollution, excess heat and water vapors have been found to have a poor impact on health, performance and productivity.

A well-designed and designed ventilation system improves the well-being of workers, and, therefore, increases labor productivity. Statistics show that indoor ventilation systems increase productivity by 410 percent.

This course project is devoted to the study of natural ventilation systems, as well as it made the calculation and design of a ventilation system with a natural impulse.

Types of ventilation and purpose

Ventilation is a set of devices and measures to ensure normal air exchange in the rooms. Ventilation systems support permissible meteorological parameters in rooms for various purposes.

Ventilation systems are divided into several types: üby the method of air circulation: natural and forced (mechanical);

by purpose: plenum and exhaust

by service area: common and local;

by design: channel and channel-free.

The main purpose of ventilation is to remove contaminated, heated, humid air from the room and supply clean, fresh air, as a result of which the necessary favorable air conditions are created.

One of the main tasks that arise during the ventilation device is to determine the air exchange, that is, the amount of ventilation air necessary to ensure the optimal sanitary and hygienic level of the air environment of the premises.

The design and operation of ventilation systems are regulated by regulatory documents:

.SNiP 41012003 "Heating, ventilation and air conditioning";

.GOST 12.4.02175 "SSBT. Ventilation systems. General requirements. "

Natural ventilation

Air exchange at natural ventilation results from the difference of air temperatures indoors and external air and also as a result of wind action.

The difference in air temperatures inside (higher temperature) and outside the room, and, therefore, the difference in densities, causes cold air to enter the room and warm air to be forced out of it. Under the action of wind, a vacuum is created on the wind side of the building, as a result of which warm and polluted air is drawn out of the room, excessive pressure is created on the windward side of the building, and fresh air enters the room to replace the drawn air.

Natural ventilation of production premises can be unorganized and organized.

At unorganized ventilation the receipt and removal of air happens through not density and a time of external protections (infiltration), through windows, window leaves, special apertures (airing).

Infiltration can be significant for residential buildings and reach 0.50.75 volume of space per hour, and for industrial enterprises up to 11.5 h-1.

Creating an Optimal Production Environment

Organized (adjustable) natural ventilation of production premises is carried out by aeration and deflectors.

Aeration is an organized natural common exchange ventilation of rooms as a result of the arrival and removal of air through opening windows. Air exchange in the room is controlled by various degrees of opening of the window (depending on the temperature of the outside air, speed and direction of the wind).

The advantage of aeration is that large volumes of air (up to several million cubic meters per hour) are supplied to the production room and removed from it without the cost of mechanical energy. The aeration system is much cheaper than mechanical ventilation systems. It is an effective means of combating excess heat in hot shops: rolling, foundry, blacksmith. The disadvantages of aeration include a significant decrease in efficiency in summer, when the outside air temperature rises, especially in windless weather. In addition, the supply air enters the room without preliminary cleaning and heating, and the removed air is not cleaned from emissions and contaminates the outside atmospheric air.

Channel natural exhaust ventilation without organized air inflow is widely used in residential and administrative buildings.

Objectives and objectives of the course project

Use of theoretical skills obtained during course study and their practical application.

Calculation of the natural ventilation system of a residential building

Calculation of air exchange of rooms and selection of sections of required diameter for ventilation shafts

Initial data for ventilation system design:

Typical Floor Plan

The number of residents in the apartment, depending on the type of apartment.

Number of floors: 4

Number of entrances: 3

Electric stove in the kitchen

Ground floor elevation: + 0.100

Floor floor thickness: 0.30 m

Apartment height: 2.55 m

Roof thickness: 0.45m

Construction area: Osh

Natural ventilation

Natural ventilation of the room - is a spontaneous movement of air masses due to the difference in its temperature conditions in non-home and inside. This type of ventilation is divided into channel-less and channel-less, relatively capable of operation is continuous and periodic.

The systematic movement of framugs, windows, doors and windows means the ventilation procedure itself. Ventilation of a channel-free type is formed on a stable base in rooms of industrial type with noticeable thermal emissions, which organizes the desired frequency of exchange of air masses in the middle of them, this process is called aeration.

In private and multi-storey buildings, a natural channel-like ventilation system is more used, the channels in which are located in a vertical position in specialized blocks, shafts or located in the walls themselves.

Natural ventilation system pros:

Cheap installation. Both the elements of the system and their installation are relatively cheaper than the elements of forced systems.

Cheapness of service. No electrical appliances are used in such systems, which means that there will be no electricity costs.

No noise from operating equipment. No fans - nothing noises.

Disadvantages of the ventilation system:

There is no way to clean the air normally. For the airflow to pass through the filter element, there must be a stably large thrust, which is not enough in the natural system.

There is no way to adjust system performance. Even if you insist on opening windows throughout the house, this may not always affect ventilation.

Dependence on weather conditions. On the same day, air exchange can vary greatly - from good (for example, if the wind blew) to almost zero, in quiet windless weather. The same applies to the time of year: in winter, ventilation can work perfectly, and in summer - on the contrary, it almost does not function.

Noise can be heard through the open windows and plenum valves, and dust and odors can penetrate from the street.

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