Moisture is one of the greatest challenges in water and wastewater installations. If not managed properly, it can cause corrosion, mold growth, and other moisture-related damage. Furthermore, improper management can lead to unnecessarily high energy consumption. Here, we share insights and solutions to optimize moisture control and minimize risks.
What is moisture and why is it a problem?
The amount of moisture in the air is measured in two ways: relative humidity (RH) and absolute humidity (AH).
- Relative humidity indicates how much water the air can hold at a given temperature.
- Absolute humidity is measured in grams of water per cubic meter of air and describes the actual amount of water in the air.
When air cools down, its capacity to hold water vapor decreases, which can lead to condensation forming on cold surfaces. This is a common cause of corrosion and mold in humid environments such as booster pump stations, pipe galleries, and reservoirs.
Typical challenges in moisture control
In water and wastewater installations, several factors make moisture control particularly challenging:
- Cold pipes and surfaces: Condensation easily forms on cold pipes, which can lead to corrosion and electrical damage.
- Underground installations: Moisture levels are often high in rock caverns and other spaces below ground level.
- Open water surfaces: Evaporation from open water surfaces can increase humidity and contribute to corrosion and mold formation.
- Ventilation and temperature control: Ventilation is often used to regulate moisture levels, but this can be inefficient if not adapted to seasonal changes.
Solutions for improved moisture control
To avoid damage and inefficient energy use, the following measures are recommended:
- Keep relative humidity below 55%: This reduces the risk of corrosion and mold.
- Use dehumidifiers instead of heating: Studies show that energy consumption can be reduced by up to five times by using dehumidifiers instead of heating to control the indoor climate.
- Account for seasonal temperature and moisture variations: In winter, outdoor air is naturally drier, whereas in summer it may contain more moisture (even if it feels dry).
- Optimize ventilation: Incorrect ventilation can lead to the ingress of humid air, which can raise indoor relative humidity to undesirable levels.
- Use the Mollier diagram to analyze moisture load: This tool helps to understand how moisture levels are affected by temperature changes and can be used when planning moisture control measures.
Major energy savings and reduced climate impact
Many municipalities have ambitious climate targets, and by optimizing moisture control, substantial energy savings can be achieved. An analysis of pump stations showed that energy costs can be reduced by SEK 7,000–10,000 per station and year by switching from heating to dehumidification. For municipalities with numerous pump stations, this can translate into both financial and environmental benefits.
Moisture control in water and wastewater installations is a critical factor in preventing corrosion, mold growth, and unnecessarily high energy consumption. By utilizing modern dehumidifiers, adjusting ventilation, and monitoring moisture levels, significant savings can be achieved – both economically and from a climate perspective.