Indoor pool separated from the living room by a glass roof in a spacious and modern house

Indoor swimming pool: how to avoid humidity problems?

Having an indoor pool is a luxury that many people would like to enjoy. Unlike outdoor pools, with an indoor pool you can swim all year round, regardless of the weather or temperature. In addition, indoor pools are much easier to manage and maintain.

In this new living space, you can also add furniture, sports equipment, decorations and upholstery that will not be affected by bad weather. However, the indoor pool (or indoor spa) has two major drawbacks compared to outdoor pools:

  • Humidity created by the indoor pool
  • The presence of chloramines and fumes from water treatment products

You will therefore need to implement solutions and a system for ventilating and heating the room at the design stage of your project.

A major source of moisture

The evaporation of the water from the indoor pool causes a saturation of the humidity present in the air of the room at a relatively high temperature. On contact with surfaces at a colder temperature, a thermal shock is created, which causes condensation, and then more or less humidity through run-off.

This humidity causes all sorts of problems in the housesuch as mouldThis can lead to damage to equipment, furniture and, in the most serious cases, permanent damage to the structure of the building. The humidity and heat from the pool water also cause great discomfort to the pool users. We will see later how to prevent your indoor pool and your house from turning into a hammam...

The presence of chloramines and treatment residues

Chloramines are chemical compounds resulting from the treatment of swimming pool water with chlorine. When present in the atmosphere, there is a high risk of corrosion of metal and stainless steel materials. In addition, an unpleasant smell of chlorine will have an unfortunate tendency to bother users inside the room.

How to spot too much humidity?

As mentioned above, the signs of high humidity from indoor pools are as follows:

  • Excessive condensation on windows or room walls
  • Puddles of run-off water
  • Abnormal warmth and 'heaviness
  • Musty stains appearing on the walls
  • Moisture odours (as in a poorly ventilated bathroom)
  • Rust on metal parts or in the pool
  • A strong smell of pool chemicals

These signs are clear indications of a lack of ventilation and dehumidification. So what is the solution, or rather solutions?

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How can you avoid moisture problems when you have an indoor pool?

There are several things you can do to avoid pool moisture problems. There are currently three main ways to dehumidify an indoor pool room:

  • Natural ventilation,
  • A condensing dehumidifier (rather than a Peltier effect),
  • Or a ventilation system.

Each installation has advantages and disadvantages and is suitable for different indoor pool configurations. However, they do not exempt you from insulating the rooms in your house as well as your swimming pool when it is not in use.

Natural ventilation

You can improve the ventilation of the room by simply installing high and low ventilation grilles on opposite walls of the room. This improves the air flow in the room. This basic solution will suffice if your moisture problem is very small.

Condensing dehumidifier

If your indoor pool is small, the condensing dehumidifier will probably be the best choice of dehumidifier available to you. It works by constantly circulating the indoor air and absorbing water through an evaporation device. The air is therefore constantly recycled.

This may be sufficient for a small poolThis will, however, result in a drop in room temperature and may require the installation of an additional heating system. This will, however, result in a drop in room temperature and may require the installation of an additional heating system. However, this will allow you to use a small amount of outside air, thus improving indoor air quality.

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The ventilation system

You may prefer to have more natural air circulating through your indoor pool area, in which case ventilation is the best choice for dehumidification. Thus, the unit you use will work differently from a condensing dehumidification unit, as the indoor air will be largely or completely replaced.

In many cases, it is preferable to opt for a controlled mechanical ventilation which uses outside air. This solution is more hygienic and provides a cooling effect. The main disadvantage is that it costs much more than a condensing dehumidifier. It also requires more space, which may not be the case if you have a small indoor pool room. You may also not be able to install a ventilation unit if the outside air is more humid than the inside air in your pool room.

Room insulation

The room where the indoor pool is located must be extremely well insulated, as must the other rooms in the house, to avoid thermal bridgesCondensation occurs when air saturated with moisture meets a colder surface. Condensation occurs when air saturated with moisture meets a colder surface. This is why you must use materials that are suitable for wet rooms. With double glazing and good insulation, condensation around the pool will be reduced.

Insulation of the pool

To reduce evaporation from the pool (or spa), it should be covered when not in use. You can cover it with a tarpaulin or an automatic cover. This will prevent the water from evaporating. This also allows the water to retain its heat, which in turn limits the energy consumption of the dehumidification, heating and ventilation equipment.

How to choose the right dehumidification option?

Choosing the right dehumidifier for your pool room can be very tricky. To get a good start on your search, consider looking at the dehumidifiers available in shops to get an idea of what's on offer. Ask your friends with indoor pools what they use for their homes and what they recommend, and don't hesitate to contact companies for quotes and opinions.

In the case of small pools or spa rooms, you may not have to make a big decision, as you probably don't need much outside air. In this case, a condensing dehumidifier will do just fine. If you have a medium to large pool or in the event that you have a strong desire for outside air and ventilation in your pool area, a ventilation system may be more suitable for your pool.

In any case, you should first ensure that you have enough space to install your dehumidifier. You should also consider the heat loss generated and therefore your need for additional heating equipment.