Service businesses, in particular hotels, offices, shopping centers, require constant ventilation. However, the basic schemes may be different depending on the purpose of the premises. In each case, ventilation has its own characteristics.
Features of hotel ventilation systems
Almost all hotels are equipped with ventilation and convection systems with primary air supply for air conditioning. Most often, the ventilation-convection system is installed in a niche, equipped behind the front door. The ventilation-convection unit forms a mixture of completely external and recirculating air, which is supplied to the room through a rectangular neck. The recirculation air is discharged through the air intake, usually mounted in the lower alcove.
In this case, the air is not fully recirculated: some of the air is discharged through the bathroom located there exhaust fan connected to the outlet duct. This is the basic scheme of operation of the ventilation and heating system that serves the hotel rooms.
The exhaust air volume is always less than the outside air supply, which creates little excess pressure in the rooms. The volumes of inflowing ambient air required for each specific hotel room must be determined either on the basis of the rules and regulations in specific region or by the recommendations of the local health authorities. Exhaust niches that remove the air from the bathrooms are displayed on the roof. In large hotels there are quite a few, which can create serious problems with the choice of location of air intake devices or the units of primary air treatment. The discharge of polluted air into the environment through the outdoor air collectors should be strictly excluded.
For restaurant halls, conference rooms and etc. it is recommended to use inflow and recirculation systems. In this case, the system supplies a mixture of outdoor and recirculating air. Mixing is carried out inside a special unit, which thus removes some of the exhaust air recirculation by means of a system of interacting flaps.
Ventilation at catering companies
Ventilation at catering companies has to meet the following requirements:
- provide flue gas, odor removal;
- prevent rising of relative humidity;
- maintain the ambient temperature at a comfortable level for visitors;
- maintain reduced pressure against adjacent rooms, preventing odors from spreading.
Typically, about 20-30 air volumes are exchanged per hour or at the rate of 60-90 m3/h per square meter of floor space. To maintain reduced pressure at the required level, it is necessary that the volume of ambient air does not exceed 85% of the volume of the excreted mass. In winter generally accepted temperature in the kitchen is of 22-24 °C, in summer it can rise to 25-30 °C. In winter, the ambient temperature should be adjusted to avoid condensation, cold drafts, etc.
Ventilation in shopping centers
Typically, the ventilation systems installed here are fully air. For multi-storey commercial buildings, there are two things to consider:
- The higher the floor, the lower the attendance. For example, there are significantly fewer buyers on the fourth floor than on the first floor. Hence the need to design a ventilation system that accommodates fewer visitors.
- As a rule, especially abroad, restaurants and eateries are located on the upper floors to attract customers. The availability of eateries and restaurants poses a number of specific problems with ventilation and exhaust air mass.