Installation i Grenaa Svømmehal

Grenaa Swimming Centre

Improved Air Distribution and Measurable Reduction in Relative Humidity

CHALLENGE: HIGH HUMIDITY AND UNEVEN AIR DISTRIBUTION

Swimming facilities are among the most demanding indoor climate environments in building operations. Large water surfaces, high water temperatures and constant activity result in significant evaporation. At the same time, heat and moisture create risks such as:

  • Accumulation of humid air beneath the ceiling
  • Uneven temperature and humidity distribution
  • Perception of heavy and stagnant air
  • Increased load on the ventilation system
  • Risk of corrosion in building structures and equipment

 

ABOUT GRENAA SWIMMING CENTRE

Grenaa Swimming Centre experienced precisely these challenges just mentioned. Relative humidity typically measured around 53–54%, and both staff and visitors experienced periods of heavy air and discomfort during prolonged stays.

For employees spending many hours per day in the hall, indoor comfort and air quality were particularly important focus areas.

The facility includes a 25-metre pool with 8 lanes, a warm-water pool, a sauna and a children’s pool.

The main pool is used for teaching and competitions, and it is above this pool that the fan has been installed. The unit is positioned high enough to allow full use of the 3-metre diving board.

Ventilator til svømmehaller og andre udfordrende miljoer - Grenaa Svømmehal loftventilator

SOLUTION: NORTHERN AIR® AQUA

To improve air distribution, a Northern Air® Aqua HVLS ceiling fan was installed above the 25-metre pool. The installation was carried out in close cooperation with lifeguard and technical manager Claus Nielsson, who also shares his experience in the video below.

The fan is specifically developed for humid and corrosive environments such as swimming facilities and features:

  • IP54 classification
  • Corrosion-protected surface coating
  • Large diameter for low-speed, even air movement
  • Operation without creating draft in the occupied zone
  • Tested by FORCE Technology

 

The purpose was not to replace the existing ventilation system, but to support it through improved air mixing.

IMPROVED COMFORT IN DAILY OPERATION

For employees working in swimming facilities, perceived air quality is crucial. High humidity combined with insufficient air movement can be experienced as heavy and uncomfortable air – particularly during longer stays.

Grenaa Swimming Centre faced exactly these issues. Claus Nielsson, lifeguard and technical manager, highlighted that they wanted to eliminate the feeling of “sweat running down your back.”

Previously, lifeguards could only remain in the swimming hall for 2 to 4 hours at a time before experiencing discomfort, headaches and fatigue due to the heavy indoor climate.

According to Claus Nielsson, the difference after installation was noticeable:

“Previously, we were around 53–54% relative humidity. Now we are around 48%. That means we no longer experience the heavy and stagnant air in the swim hall.”

The improved air movement creates a more comfortable occupied zone – without causing draft, which is essential in an environment where guests are dressed in swimwear.

MORE UNIFORM DISTRIBUTION OF HUMIDITY AND TEMPERATURE

Stratification is common in swimming facilities:

  • Warm and humid air accumulates beneath the ceiling
  • The occupied zone is affected by stagnant air
  • Ventilation efficiency is reduced


An HVLS fan creates controlled, slow and continuous air circulation that:

  • Reduces temperature gradients between ceiling and floor
  • Distributes humidity more evenly throughout the space
  • Minimises local accumulation of chlorine-related by-products
  • Supports the ventilation system’s removal of moisture and airborne compounds

 

The measured change in relative humidity can be attributed to improved air distribution and better interaction between air circulation and the existing ventilation system.

Shortly after installation, both staff and users noticed a difference. The fan effectively mixes the air, contributing to a reduction in measured relative humidity in the occupied zone. This homogeneous air distribution improves indoor comfort – without creating draft.

As Claus Nielsson explains:

“This is a swimming hall where people walk around in shorts and swimwear. That always has to be taken into account. Finding the right balance in the indoor climate is a major challenge.”

NICKNAMED “THE WONDER”

The Aqua fan has helped Grenaa Swimming Centre move closer to that balance – to such an extent that the unit has earned the nickname “The Wonder.”

The improved air conditions have created a better working environment, as the heavy air no longer causes the same level of discomfort, and the feeling of excessive humidity has been significantly reduced. This improvement benefits both visitors and lifeguards.

 “Previously, we had 53–54% relative humidity. Now we have reduced it to 48%. It means you no longer feel sweat running down your back, and the heavy air is gone. It feels light and pleasant when you enter the hall.”

Claus Nielsson

Lifeguard and Technical Manager, Grenaa Swimming Centre

IMPROVED INDOOR CLIMATE – FOR PEOPLE AND BUILDING

Reduced Risk of Local Moisture and Corrosion Impact

The larger the pool surface, the higher the water temperature and the greater the activity level, the greater the evaporation – and consequently the higher the humidity load in the swimming facility.

Corrosion is therefore a well-known challenge in swimming environments. The combination of high relative humidity and chlorine-based compounds can over time affect everything from structural elements to equipment.

Although the fan does not actively dehumidify the air, it supports a more controlled and uniform moisture profile in the space and can therefore form part of a long-term building preservation strategy.

ENERGY AND OPERATIONAL PERSPECTIVE

The installation in Grenaa Swimming Centre was completed within a few days, without prolonged operational shutdown and without modifications to the existing ductwork.

The solution functions as an effective supplement to the ventilation system by stabilising temperature and humidity distribution while improving comfort in the occupied zone.

In swimming facilities, it is rarely about a single solution – but about optimising the interaction between ventilation, temperature control and controlled air movement.

Grenaa Svømmehal mindsker relativ luftfugtighed med ventilator

MEET NORTHERN AIR® AQUA

The Northern Air® Aqua fan equalises temperature and humidity differences through continuous air mixing.

FORCE Technology has tested the system for resistance to water and dust. The complete system is IP54 classified, meaning it is protected against dust ingress and resistant to splashing water.

This makes Aqua particularly suitable for swimming facilities, where indoor climate conditions are demanding and environments are corrosive. The entire system – from mounting brackets to blades – is coated with a specialised protective finish to minimise the risk of corrosion.

For further information and technical specifications, please visit the product page.

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