Analysis of HVAC design in small indoor swimming pool
Column:Industry News Time:2018-11-15
With the improvement of people's living standards and the pursuit of quality of life, more and more star-rated hotels are equipped with indoor swimming pools during construction. Indoor swimming pools are...

With the improvement of people's living standards and the pursuit of quality of life, more and more star-rated hotels are equipped with indoor swimming pools during construction. Indoor swimming
pools are required to keep the indoor swimming pool in a comfortable environment, whether in summer or winter. Therefore, air conditioning equipment is required. This article will do some work on
the design of the swimming pool.

The project is located in the Xiamen area and is a swimming pool for a five-star hotel. The total area is about 700m2, including a 140m2 adult pool and children's paddling pool and surrounding space.
The same floor of the swimming pool is equipped with constant temperature and humidity machine room. It is equipped with constant temperature and humidity air conditioning unit. It has its own cold
source. The lack of cold and heat source is provided by the hotel's large system. The unit has its own heat recovery device.

Design Parameters

1.1 Indoor swimming pool features and design difficulties

(1) The air temperature in the hall is high (28 °C ~ 30 °C, the general building indoor temperature is 20 °C ~ 26 °C), the space is large, the glass area is relatively large, and sometimes there is a light-transmissive
roof; due to the large number of pools and poolside floors Water vapor is emitted into the air, and the indoor temperature and relative humidity are higher than those of ordinary buildings. Therefore, more
ventilation is required to eliminate residual moisture than in general buildings.

(2) The water in the swimming pool is treated with liquid chlorine sterilization. The chlorine gas is emitted into the air. When the content exceeds 1ppm, it will endanger human health. The acid gas formed by
the combination with the water vapor in the air will seriously corrode the metal products in the museum.

(3) Resolving the condensation on the roof and exterior walls of the pavilion and the problem of corrosion prevention are important issues to be solved in the design of the swimming pool.

1.2 Determination of interior design parameters

For small recreational swimming pools, the water temperature of the pool should generally be 2 °C ~ 3 °C higher than the specified water temperature of the competition pool (24 °C), so that the swimmer
does not feel "too cold". According to the data of various countries, in order to ensure the comfort of the personnel after the water and before entering the water, the air temperature in the pool should be
higher than the temperature of the pool water by 1 °C ~ 2 °C, the design standard of the international swimming pool is higher than 2 °C, in the case of the same moisture content. Underneath, the amount
of water in the pool can be reduced, thereby reducing the amount of ventilation. If the temperature in the hall is too low, the swimmer will feel "cold" when it comes ashore; if the temperature is too high, the
poolside staff will feel stuffy. The water temperature of the project is set to 26 ° C, the indoor air temperature is 28 ° C, and the relative humidity is 60%.

The air flow rate in the pool area is controlled to be around 0.2 to 0.25 m/s, because the air flow rate on the pool surface directly affects the evaporation of the pool water. When the water temperature and
air parameters are constant, the pool water evaporation is proportional to the air flow rate. If the wind speed is too high, the swimmer will feel a blow when going ashore; if the wind speed is too low, the
airflow will be difficult to organize. Therefore, the wind speed at the pool surface and the pool side is not more than 0.3 m/s, and is generally set at about 0.2 m/s.

Calculation of dehumidification

Firstly, the amount of indoor moisture is calculated. The indoor moisture content includes three parts: open water surface moisture, human body moisture and fresh air moisture.

4. Anti-condensation problem of the swimming pool enclosure structure

4.1 Contamination hazards

After condensation, the inner surface of the wall and the roof will be mildewed, which will affect the lighting of the glass and even affect the mechanical properties of the main structure. The consequences of
condensation on the wall and the floor are still very harmful. The condensation will produce mold and the mold will cause mold. Not only will it release allergic substances, causing allergies, some highly toxic
molds, but also cause serious lung disease and even death.

4.2 Causes of condensation

The indoor temperature of the swimming pool is generally above 24 ° C, and the relative humidity is greater than 60%. According to the international swimming pool design specification, the indoor air moisture
content should not be greater than 14g / (kg. dry air), which means that the air dew point temperature does not exceed 20 °C. In the winter, the outdoor temperature is low, and if the maintenance structure is not
well insulated, condensation will be formed on the inner surface of the indoor maintenance structure.

Therefore, the project puts forward certain requirements for the building envelope structure, and determines the structure of the insulation wall according to the K value so that the K value is less than 3.16 W/(m2 °C).
In addition, the material and arrangement of the insulation layer should be reasonable. Since the temperature difference in the material layer on the outdoor side is large, the insulation layer must be disposed on the
outdoor side. Insulation materials must use materials with low water vapor permeability and no water absorption or water repellency. Such materials facilitate the penetration of water vapor and reduce the likelihood
of condensed water accumulation. Bulk rock wool and glass wool should not be used. These materials are not good for the elimination of condensed water, but also because of their large compression ratio. In the case
of poor construction level, it is difficult to ensure the true thickness, thus affecting the insulation. effect. The material and arrangement of the vapor barrier should be appropriate. The vapor barrier should be placed on
the indoor side. The purpose of setting the vapor barrier is to prevent steam from penetrating into the room from the inside and avoid condensation inside the enclosure. Preferably, the vapor barrier layer is made of a
stainless steel plate or an aluminum plate having a large water vapor permeation resistance. Therefore, the load-bearing structure with large capacity, good compactness and large water vapor permeation resistance
should be arranged on the indoor side, which is beneficial to reduce wet penetration. A better practice is to use metal sandwich insulation board to keep warm and separate steam, and pay attention to the tightness
between the board and the board, otherwise it will not be able to escape once moisture enters. The outer surface layer should be made of a material with good gas permeability so that the water vapor transmitted
through the indoor side can be smoothly distributed.

5, the swimming pool air conditioning automatic control

The temperature and humidity sensors are installed in the pool hall to set, display, start and stop and alarm the temperature and humidity and operation status of the air conditioning system, and send the collected
signals to the control cabinet of the air conditioning unit. The control cabinet sends out the signal adjustment unit electric fresh air valve. The air valve water valve opening degree and the speed of the sending and
exhausting fans are controlled automatically by the control ventilation system to achieve the optimization of indoor parameters and energy conservation.

This paper focuses on the calculation method of the dehumidification capacity of the swimming pool air conditioner, the equipment selection, the hazard of condensation and the main points of anti-condensation.

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