Design of ventilation, air conditioning and heating systems is regulated by SNiP 2.04.05-91. In accordance with the principles of construction, design decisions should not:
- disturb air purity;
- create excessive noise or vibration in the premises, in particular, at the installation site, the noise level should not exceed 110 dBA;
- to be fire hazard.
In addition, the design
of ventilation and heating systems should provide for maintainability of the equipment. This may surprise the owners of personal cottages, but typical
project documentation includes a calculation of the number of personnel who must operate the equipment. Otherwise, everything is pretty obvious: the presence of aggressive media in air ducts requires corrosion resistance from pipelines and air ducts, and hot surfaces are inevitably insulated, which implements the idea of fire safety, already mentioned above. If insulation does not help to reduce the temperature of some sections of the designed system to safe, then placing them in rooms where flammable aerosols or gases are possible is strictly prohibited. And such premises should be considered separately when designing ventilation systems. Any non-standard elements of the system must be made of materials approved for use in construction.
The general calculation for the premises where people work is carried out:
- In the summer - based on the maximum temperature allowed in the room with the formation of excess heat. In the absence of such, an economically feasible temperature is selected from the allowed range. The calculated data are indicated in the applications, and not everything is so obvious here. The temperature cannot exceed 28 ° C, but at lower indices of this, the environment begins to vary accordingly. Design of air conditioning and ventilation systems is aimed at fulfilling the above requirements.
- In winter - based on the economic feasibility of maintaining a certain temperature in the room, which is in the allowable range. With a minimum temperature easier, it should not be below 14 ° C.
In this case, the flow velocity and relative humidity are also selected from a number of acceptable values.
For fully automated rooms where people are not constantly located, the rules prescribe a slightly different approach:
- In warm time, operation is allowed at an air temperature equal to the outside, and if excess heat is generated in the room, the design of ventilation systems should set the task of forcing the temperature difference to 4 degrees. At the same time, the temperature in the room should not be lower than 29 ° C, otherwise you can not pay attention to the temperature difference inside and outside. These conditions are true if additional air heating is not required.
- In the cold season, if there is no excess heat, you need to maintain a temperature of 10 ° C, if there is an excess of heat, the design of ventilation systems should be aimed at maintaining an economically feasible temperature.
Climatic operating conditions should be taken according to the annexes of SNiPa II-3-79.