How to Properly Ventilate an Indoor Pool

Written by Michael Dean
June 30, 2023

ventilating an indoor swimming pool

Indoor pools offer several major benefits over outdoor pools. For one, you get to enjoy swimming throughout the year, even as the temperature begins to drop. Also, indoor pools have more privacy since they are fully enclosed. That said, indoor pools require ventilation and humidity control, which can be challenging to set up.

In this article, I’ll go over how to properly ventilate your indoor pool, the costs associated with the project, and review the required permits and regulations you should consider to have an adequately ventilated pool. Let’s jump straight in!

Main Takeaways

  • Ventilation helps control humidity levels, preventing mold and mildew formation and protecting the structural integrity of the pool area.
  • Fumes from chlorine and other chemicals can harm your respiratory system without ventilation.
  • Implementing energy-saving measures can help minimize energy consumption while maintaining proper airflow and humidity control.
  • The ventilation system itself will cost between $1,400 to $20,000 on average.

Do Indoor Pools Need Ventilation?

Yes, absolutely! Proper ventilation is one of the most important things to include in your indoor pool. Sufficient airflow is vital for maintaining a safe and healthy environment. Without ventilation, your pool room will become excessively humid and filled with potentially toxic fumes from the chemicals in the pool. Here are some of the top reasons your indoor swimming pool needs ventilation.

Health and Safety

Chlorine is the most common chemical used to sanitize pool water. While it gets the job done, the fumes from chlorine can linger in the air if they have no other place to escape. This can cause respiratory and other health issues.

Proper ventilation will also keep the chloramine (a dangerous byproduct of combined chlorine) levels in check, ideally to 0.4 ppm or less.

Humidity Control

Ventilation is also vital for controlling humidity and preventing mold and mildew from forming. The presence of moisture can lead to condensation and structural damage. Over time, moisture buildup can cause corrosion, rusting, and deterioration of materials such as metal fixtures, wooden structures, and electrical systems. So, using ventilation ensures fresh air is continuously circulated, replacing the highly humid air in the pool room with fresh air from outdoors.

Comfortable Pool Environment

Continuous fresh air circulation eliminates stuffiness and creates a pleasant pool environment. 

Maintaining a comfortable temperature and reducing odors will make your indoor swimming experience all the more enjoyable. After all, who wants to be breathing in wet air and chemicals?

How to Properly Ventilate an Indoor Pool

No matter how big your indoor pool is, proper ventilation is a manifold process that requires experience and careful attention to detail. Let’s closely look at the steps needed to ventilate an indoor pool.

Your goals in ventilating a pool are:

  • Manage humidity levels
  • Circulate fresh air into the pool room
  • Conserve energy (ventilation systems can be very expensive to run)

Step 1: Managing Humidity Levels

Humidity control is a crucial aspect of indoor pool maintenance. The ideal humidity levels of an indoor pool room are around 50% to 60%. Here are my top recommendations for maintaining this level.

  • Monitor humidity levels: Use reliable hygrometers to regularly measure the humidity inside the facility. 
  • Prevent deviations: Keep humidity above 50% to avoid excessive evaporation, as dry conditions result in more evaporation. You also want to ensure humidity does not exceed 60% to prevent corrosion, structural damage, and condensation that can result in mold.

Step 2: Implementing Effective Ventilation Systems

Proper ventilation is essential for maintaining fresh, clean air inside the swimming pool area. There are several different types of ventilation used in indoor pools. The type that is right for you depends on your budget and the size of the pool room.

Whole-Home Dehumidifier

A whole-home dehumidifier is a ventilation/dehumidification system that essentially connects your indoor pool to the rest of your home. This system tackles ventilation and humidity at the same time and is relatively cost-effective. I don’t recommend using whole-home dehumidifiers for larger indoor pools, though, as they won’t be enough to handle that humidity level.

Ventilation-Based Dehumidifier

Ventilation-based dehumidifiers replace the humid, chemical-filled air inside a pool room with fresh air from outside. These work very well, especially if you live in a warm, dry climate. However, unfortunately, ventilation-based dehumidifiers will not work well if you live in a humid climate.

Mechanical Refrigeration System

Mechanical refrigeration is the most popular type of ventilation used in indoor pools and is also the most effective. Mechanical refrigeration systems draw in the humid air in a pool room, cool the air, extract the moisture, and return the fresh air back to your indoor pool.

Here are some tips for effectively ventilating your indoor pool:

  • Chloramine control: It is crucial to have an efficient ventilation system that expels chloramines outside the facility to prevent those dangerous chlorine byproducts from accumulating in the pool area.
  • Air extraction: Install low-level return vents to extract air from the water’s surface. This will help remove contaminants and promote air circulation.
  • Air pressure management: Maintain a slight negative air pressure within the pool area to prevent contaminated air from spreading to other areas. Another thing that can help with this is to have automatic door closers, which will restrict air movement between different parts of the building.
  • Even air distribution: Install air ducts and ventilation systems to ensure even air distribution throughout the facility, avoiding stagnant areas.

Step 3: Energy Conservation Measures

Indoor pool dehumidification and ventilation can be very expensive to run. The last thing you want is to find that you have to pay a hefty electrical bill for running your indoor pool.

So, in addition to maintaining air quality, you’ll also want to implement energy-saving practices. Consider the below steps to conserve energy in your indoor swimming pool:

  • Opt for a whole-home or ventilation-based dehumidifier: Although mechanical refrigeration is by far the most effective type of pool ventilation, it is also the most expensive to run. So, if you can, opt for one of the other two types of ventilation systems.
  • Use a pool cover: Pool covers help reduce evaporation and also assist in lowering the humidity in an indoor pool area. This is because when you use a pool cover, the air will not be as moist. You can even turn off your ventilation system when the cover is on, reducing energy costs.
  • Maintain air temperature: As a general rule, maintain an air temperature of 2 degrees higher than the water temperature inside your pool room to minimize evaporation (up to a maximum of 86 degrees Fahrenheit).

Other Things to Consider When Ventilating an Indoor Pool

Here are some other important things to consider when ventilating an indoor pool.

Regulations and Permits

Unfortunately, many aspects of building a pool require permission from your local municipality or equivalent authority. I know this can be a huge bummer and a headache! But you’ll need to comply with local regulations and obtain the necessary permits to ensure your indoor pool and ventilation system is safe. Be aware of specific requirements regarding air quality, ventilation rates, noise levels, and safety measures.

Consult with your local municipality or a pool expert to ensure your pool facility meets the necessary standards.

Air Distribution and Vent Placement

Proper air distribution is crucial to prevent stagnant areas and maintain consistent flow ventilation throughout the whole pool area. Strategically place vents and ensure the indoor pool gets the optimum airflow to control the room’s temperature and prevent heat buildup. 

I recommend consulting with an experienced architect or HVAC professional, as this can be a complicated procedure to DIY.

Building Materials

Always use moisture-resistant materials like Dryvit in an indoor pool room. If you are unsure what type of materials to use in your pool room to ensure your structure is moisture-resistant, feel free to contact me!

Cost of Indoor Pool Ventilation

Of course, one of the main things to consider when it comes to anything pool-related is the cost! Indoor pool ventilation is no different. So, what can you expect in terms of upfront costs, ongoing costs, and maintenance costs? Let’s break it down.

Upfront Costs

Of course, buying and installing the dehumidification system in the first place is a major cost consideration! The price varies depending on the type of system you choose.

  • Whole-Home System: Installing a whole-home dehumidification system, which integrates with the existing HVAC unit, typically ranges from $2,000 to $8,000.
  • Ventilation-Based System: A ventilation-based system that utilizes outside air for humidity control may cost between $4,000 and $10,000.
  • Mechanical Refrigeration System: The most popular option, a mechanical refrigeration system, can range from $4,000 to $20,000, depending on the unit’s type and size.

Depending on the existing setup, you may need to make modifications to accommodate the ventilation system, such as ductwork installation or electrical adjustments. These modifications can add to the upfront costs and should be factored into your budget.

Ongoing Costs

Properly ventilating an indoor pool requires energy to operate the ventilation system and maintain ideal conditions. The ongoing costs will primarily depend on the type of ventilation system you choose. For example, mechanical refrigeration systems tend to consume more energy than ventilation-based or whole-home systems, but they are by far the most effective choice for an indoor pool!

Maintenance Costs

Regular maintenance is essential to ensure the proper functioning of the ventilation system. This includes filter replacements, cleaning coils, inspecting ductwork, and addressing any issues that may arise. Maintenance costs can vary widely. For example, regular inspections, cleaning, and minor repairs shouldn’t add up to more than a couple hundred dollars a year. However, significant repairs or component replacements could result in much higher costs – even up to the thousands!

Check out my indoor pool cost guide for more information on all things cost-related.

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Frequently Asked Questions

What temperature should an indoor pool be?

The ideal temperature for an indoor pool typically ranges between 78 to 82 degrees Fahrenheit (25 to 28 degrees Celsius). And the general rule of thumb is to keep the air temperature around 2 degrees Fahrenheit warmer than the pool water – up to a maximum of 86 degrees. This helps keep evaporation in check!

What is the ideal humidity for an indoor pool?

The ideal humidity level for an indoor pool is between 50 and 60 percent. If the humidity is too low, your pool water will evaporate; if it’s too high, you might notice condensation on your walls!

Does an indoor pool need a dehumidifier?

Absolutely! Indoor pools need a dehumidification system to effectively control humidity levels. A dehumidifier helps remove excess moisture from the air, preventing condensation, mold, and a host of other issues.

Do indoor pools evaporate?

Yes, surprisingly enough, indoor pools do experience evaporation. The evaporation rate can be influenced by factors such as pool water temperature, air temperature, humidity levels, and air circulation.

Ventilation is Key!

Now that you know how to ventilate your indoor pool, you’ll be able to fully enjoy your swimming experience. While setting up the ventilation system may seem daunting at first glance, it is a straightforward process that will benefit you and your pool.

Let me know if you have any more concerns regarding indoor pool ventilation. I’m happy to answer any questions you may have!

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