Ventilation of the pool: the scheme and details of design. The system of supply and exhaust ventilation

Why do you need ventilation in the pool? In order to maintain an appropriate climate, in particular humidity and temperature, any pool should be equipped with a reliable and properly designed system of supply and exhaust ventilation. Ventilation of the basin is especially important for large objects, swimming pools in health-improving institutions, etc. Do not forget about ventilation and when designing small swimming pools in private houses. The pool ventilation system should be carried out with strict compliance with sanitary and hygienic standards.

The account of the normalized parameters of the air environment

The criterion for the correct design of the pool ventilation system is compliance with environmental standards, in which any pool visitor would feel comfortable enough. In addition, it is necessary to pay due attention to such parameters as humidity level and temperature in the pool area. Ventilation of the pool is an important element that must be taken into account at the design stage of construction.

The main of these parameters are:

- permissible humidity level, which should not exceed 65%;
- the correspondence of the water temperature to the ambient air temperature: this difference is allowed by no more than 2 degrees;
- Optimum water temperature in the basin: there are different opinions on this matter, but in general it should be within 30-320C (for pools where water is heated);
- taking into account the comfort of the swimmers' stay outside the water, the maximum permissible value of the air speed in the pool room is set - no more than 0.2 m / s.
When installing ventilation systems, it is necessary to take into account an important criterion, such as the value of the calculated air exchange - it must be at least 80 m3 / h for each visitor. The throughput, that is, the estimated number of visitors to the basin, must be taken into account at the beginning of project development. Thus, even at the design stage, the pool ventilation should accurately determine the maximum flow capacity of the pool.
As is known, the difference in the volume of air supplied to the room and removed from it is also of decisive importance. Otherwise, visitors can constantly overcome either a feeling of stuffiness (with excess supply air) or a draft (with excess air being removed). Both are particularly inadmissible in swimming pools with health-improving organizations. The allowable difference should not exceed 50% of the total air exchange rate.

In addition to purely hygienic indicators, ergonomic indicators, in particular noise, are of great importance in the design of the ventilation and conditioning system. Ventilation equipment should be installed in such a way that the level of noise produced by it is minimal (without affecting the design performance of the fans). The noise level in this room should not exceed 60 dB. Ventilation and air-conditioning systems must strictly comply with all sanitary norms and rules. These norms are clearly regulated by the legislation of the Russian Federation and are prescribed in the relevant SNiPs and GOSTs and other normative documents.

Features of the development of the pool ventilation system

Since this is a room where a significant number of people are constantly present, the supply and exhaust ventilation must completely exclude the formation of any harmful factors during operation, both for people and for pool devices. In the latter case, we mean the condensation of moisture vapor, which, in the presence of a large water space (and at a slightly elevated temperature against normal water temperatures) leads to a gradual accumulation of moisture on the surfaces of the ventilation shafts. Given the material of these surfaces in such cases, premature venting of the ventilation ducts is expected due to corrosion. Moreover, particles of rust, falling into the range of fans (especially vulnerable to fresh air ventilation), can cause jamming of their working planes and the accident of production equipment.
The way out is to ensure effective protection of the working surfaces of the ventilation shafts without compromising their operability.

Isolation system

Isolation can be carried out in two ways:

- the creation of corrosion-resistant protective screens made of durable plastic;
- the use of intake valves with the presence of electric heating, which would quickly handle the change in temperature and humidity conditions in ventilated rooms.
- using steam traps.

Building a swimming pool in a private house

As for public pools, private pool ventilation is designed taking into account all the above circumstances, but the ventilation equipment capacity, based on the smaller area of such a pool, as well as a limited number of visitors, may be lower. In particular, it is necessary to take into account the fact that the individual pool operates as needed. Therefore, the required equipment may have less performance. However, during the design process, it is possible to provide installation of additional supply air systems and exhaust ventilation systems, which will be included in the help to the main equipment with full use of the pool. This eliminates the over-expenditure of electricity, but ensures the optimal value of air exchange in it. At the same time, the organization of the ventilation system and the requirements regarding the safety of its use should be maintained at the same level as for the ventilation equipment of public pools.

Indices taken into account in calculating the ventilation of the basin

1. The area of the room.
2. Estimated multiplicity of air exchange for supply and exhaust ventilation of the pool.
3. Normative values of air supply per visitor.
4. Allowable air temperature in the room.

At the same time the system of supply and exhaust ventilation, developed for such conditions, must solve the set tasks with the greatest possible compactness of the nodes included in it. For this purpose, we select the best in terms of overall dimensions and performance of air heaters, fans, as well as a system of working filters. The developed monoblock systems of these nodes largely meet the requirements. Moreover, when choosing a ventilation system, it is possible to provide for the recovery of excess heat from the fans, in order to partially reduce the heating costs of the pool room. Achieved at the same time, energy savings of up to 25%. However, with sufficient justification of the climatic zone of the construction of the basin, as well as its volume, it is advisable to install additional sources of heating, for example, water heating. If for the purpose of such heating it is assumed that water is taken from the general system of its supply to the pool, additional water treatment filters are necessarily provided for the design, since the water for use in the pool and the technical water for heating have sharply different quality requirements and are regulated by different GOST. Usually pools of individual use are rarely located in the main building - often in a special annex or in a separate building. Accordingly, the ventilation of the pool in this case should be designed independently of the main ventilation system of the building. In order to reduce the moisture capacity in the pool, which entails damage to the ventilation shafts, the water mirror is usually closed. This reduces the volatility of water, reduces the overall moisture index, virtually eliminates the need for additional pumping water in the pool.

Principles of calculation power calculation

The parameters given above can be taken as a basis, however, some changes are allowed for the private pool. In particular, the lower limit of relative air humidity in some cases can be reduced to 50%. This is due to the fact that the number of visitors to such a pool is relatively small and the discomfort from lowered humidity levels will not be so noticeable. At the same time, the risk of condensation on the walls of the pool building is also reduced.
The design of the system of supply and exhaust ventilation begins with the specification of the actual air flow. There are experimental tables, which set the temperature in the pool and the area of its bowl. Depending on these parameters, based on the data in the table, you can easily set the required value for the hourly average air supply. In the same way, it is also possible to determine the required power of ventilation plants. For example, with a pool area of 32 m2 and a design temperature of 340C, the required air flow rate should be 1 100 m3 / h. The corresponding capacity of electrical equipment is 20 kW.

Parameters of calculation of ventilation of the basin

Preliminary calculation of the pool ventilation in accordance with the technical requirements, it is necessary to consider the following parameters:

- area of the working mirror of the pool;
- the surface area of the tracks surrounding the pool;
- total area of the basin;
- temperature of the outside air in the pool construction area (separately for the coldest and for the warmest five-day periods of the year);
- minimum water temperature in the pool;
- minimum air temperature;
- estimated number of pool visitors;
- The design temperature of the air removed from the pool room (necessary to determine the risk of condensation).

Considered indicators

- Heat exchange in the pool area due to solar heat in summer, from visitors actively using the pool, from the water heated for the pool, from its evaporation from the surface, and from a number of other factors.
- Heat exchange due to the difference in water temperature in the pool (with an increase in the number of swimmers, the average water temperature rises).
Calculated data for ventilation of the basin must be compared with the standard values of air exchange. Based on the calculation, the draft of the extract and input ventilation is sometimes adjusted. This takes into account possible fluctuations in the initial data due to the difference in outdoor temperatures in the warm and cold seasons. Accordingly, the total capacity of the ventilation plants for the two versions of the pool operation is determined. If necessary, reserve areas are laid in the design solution for installation of additional ventilation units. It is necessary to take into account additional areas on which additional ventilation can be placed to ensure the uninterrupted supply of fresh air to the pool room. In addition, the reserve area, on which additional exhaust ventilation can be placed to ensure the outflow of "exhausted" air, is also taken into account.

Designing of ventilation

First, some allowance for the level of permissible humidity is allowed. Secondly, the values of the actual air flow are taken into account. In this case, experimental data of indices calculated for similar structures are often used.
The designed ventilation of the basin requires calculations.

Weight volume of incoming air

W = exFxPb-PL, kg / h.
In this formula:
F - estimated surface area of the water in the pool, m2;
Pb - design pressure for evaporation of moisture (for conditions of high humidity and at a certain temperature of water in the pool), Bar;
PL - water vapor pressure at standard values of temperature and humidity, Bar.
Since this dependence is used in calculations in Germany, where 1 bar is used as the pressure unit, it is worth recalling for practical application of the formula that 1 bar = 98.1 kPa.
E is the intensity factor for evaporation, kg (m2 * h * bar), which depends on the specific design and operating rules of the pool. For swimming pools, the water surface of which is covered with a film, this figure is 0.5, and for an open surface - 5.
The values of this indicator sharply increase with an increase in the number of visitors:
- with a small number of them - 15;
- with an average of 20.
- with a significant number - 28;
- additionally, in the presence of water attractions - 35.

Air consumption by its mass

ML = GWXB-XN, kg / h,
And the air flow by its volume - according to the dependence.
L = GWrxXB-XN, kg / h.
Here:
L - volumetric flow, m3 / h.
ML is the mass flow rate, kg / h.
GW is the total volume of moisture evaporating in the pool room, g / h.
XN - moisture mass outside the basin, g / kg.
XB - moisture mass inside the basin, g / kg.
R - density of air in the room for a given temperature regime, kg / m3.
It should be noted that the moisture content in the basin varies with the season. In winter it is 2-3 g / kg, and in summer - 11-12 g / kg. Usually average values of 8-9 g / kg are taken into account.

Installation and installation work

Installation of ventilation systems is carried out with careful sealing of pipelines and protection from heat loss in them. It is absolutely impermissible to direct the flow of air to the water surface of the pool. If the ventilation system has small overall dimensions, then it is advisable to mount it in the inter-ceiling space of the pool. For reasons of possible short-circuits and subsequent fires, the installation of air-conditioning units built into this system is prohibited. Thus, the installation of ventilation systems is not as difficult as it may seem initially.