Heating and ventilation systems INTRODUCTION

Heating and ventilation systems belong to the engineering networks of buildings and are life-support systems designed to maintain optimal temperature, humidity and other parameters of the air environment in the premises. Without this, the permanent stay of people in buildings is impossible.

In the cold season, a person is forced to provide indoor air temperature above the outside in the premises. The process of maintaining such an internal temperature is called heating . Thermal energy supplied to the room by the heating system is transmitted to the internal air, and at the same time from the internal air the heat flow through the external enclosures is directed from the room to the outside. The balance of these two processes determines the temperature of the internal air.

In the process of human life and during technological processes, so-called harmful substances are emitted into the room air - substances (gases, vapors, dust), the increased concentration of which in the air is unfavorable to humans. Ventilation systems are designed to remove polluted air from the premises and supply clean air to them.

In Russia, large centralized heat supply systems developed predominantly, ensuring the operation of building heating systems. Combustion of fuel at large heat and power plants makes it possible to realize the most efficient thermodynamic cycles in the joint production of heat and electrical energy and improve the state of urban air.

In recent decades, the use of autonomous heating systems serving a single building or a small number of them has been expanding. At the same time, it is possible to use both electricity and direct fuel combustion (gas, liquid petroleum products) to prepare the coolant. Modern boilers, the efficiency of which is 92–95%, insignificant losses in heat networks, automatic control capabilities ensure higher economic efficiency of such systems.

A significant effect comes from the use of modern heating devices and equipment in heating systems - aluminum radiators, metal-polymer pipes, and lamellar water heaters.

Opportunities for the placement and convenient operation of utilities and equipment that provide a favorable indoor climate are provided for in the design of the building.

The tutorial on specific examples outlines the method for selecting the basic parameters of the indoor microclimate, calculating heat losses and, accordingly, the design load of heating and ventilation systems, designing and calculating these systems, and selecting the necessary equipment.

Calculations of heating and ventilation systems are based on the laws of physics, hydraulics, and aerodynamics.

When performing a course project (work), the student must learn to design and calculate the heating and ventilation networks of a simple construction. To do this, he must know the basic principles of heat engineering calculations, the laws of fluid and gas flow through pipeline systems.

The assignment for the course project for students of the IIEP is given in Appendix. 15.
The variant of the task should be chosen in accordance with the code indicated in the student's record book. For full-time students, the task is given by the teacher.

In developing the project, in addition to this manual, you should familiarize yourself with the basic normative and educational literature contained in the bibliographic list.