The Microwell DRY X 1200 DUCT is a ducted swimming pool dehumidifier that removes excess moisture through controlled ventilation and heat recovery.
Unlike conventional refrigeration-based pool dehumidifiers, it requires no compressor, refrigerant or refrigeration circuit. It supplies up to 100% fresh outdoor air, extracts humid pool air and uses the difference in absolute humidity to dry the indoor swimming pool environment.
How does fresh-air pool dehumidification work?
A typical indoor swimming pool operates at approximately 30°C and 60% relative humidity. Under these conditions, the air contains around 18.2 g of water per m³.
The DRY X 1200 DUCT continuously compares the indoor and outdoor air conditions:
- Humid air is extracted from the indoor pool hall.
- Fresh outdoor air is supplied to the building.
- When the outdoor absolute humidity is below 18.2 g/m³, the incoming air can absorb moisture from the pool environment.
- The humid indoor air is then discharged outside.
The system therefore dehumidifies the swimming pool through the difference between indoor and outdoor absolute humidity.
Why is absolute humidity more important than relative humidity?
Relative humidity depends strongly on air temperature. For this reason, outdoor relative humidity alone does not show whether fresh air can effectively dehumidify an indoor pool.
Absolute humidity indicates the actual quantity of water contained in one cubic metre of air.
For example, cold outdoor air may have a high relative humidity but still contain significantly less water than warm pool air. After this fresh air enters the pool hall and is heated, its relative humidity drops and it can absorb additional moisture.
For ventilation-based pool dehumidification, the critical question is therefore:
Does the outdoor air contain less water per m³ than the indoor pool air?
If the answer is yes, the outdoor air can be used for effective dehumidification.
How often can outdoor air dehumidify an indoor pool?
Indoor swimming pools have a warm and humid climate throughout the year. In typical Central European conditions, the outdoor absolute humidity is lower than the absolute humidity inside the pool hall during approximately 358 days per year.
This means that fresh outdoor air can provide effective pool dehumidification during practically the entire year.
Actual operating conditions depend on:
- Geographic location
- Outdoor temperature and humidity
- Pool water temperature
- Indoor air temperature
- Required indoor relative humidity
- Pool size and evaporation load
- Pool cover and operating schedule
What happens during extremely hot and humid weather?
During a small number of exceptionally humid summer days, the outdoor absolute humidity may reach or exceed the indoor pool humidity level. Under these conditions, ventilation alone cannot provide the required dehumidification capacity.
For year-round humidity control, the DRY X system can be combined with Microwell Synairgic technology.
The Synairgic combination supplements fresh-air dehumidification when outdoor conditions become unfavourable. It covers the short periods when the outdoor air is too humid to remove sufficient moisture from the pool hall.
The result is a complete solution:
- Fresh-air dehumidification during most of the year
- Additional dehumidification during exceptional humid periods
- Reliable year-round indoor pool climate control
- Optimised energy consumption based on actual conditions
Heat recovery reduces ventilation losses
Ventilation removes humid air, but untreated ventilation can also discharge valuable heat from the building.
The DRY X 1200 DUCT therefore includes a counterflow heat exchanger. Energy from the warm extracted pool air is transferred to the incoming fresh air before it enters the swimming pool hall.
This heat recovery process helps to:
- Preheat the incoming outdoor air
- Reduce building heat losses
- Lower the demand on the heating system
- Improve the overall energy efficiency of the pool ventilation system
- Maintain a more stable indoor pool temperature
A refrigerant- and compressor-free pool dehumidifier
The DRY X 1200 DUCT does not require a conventional refrigeration circuit for standard ventilation-based dehumidification.
No compressor. No refrigerant. No refrigeration circuit.
This design offers several important advantages:
- Quiet operation
- Low mechanical complexity
- Reduced servicing requirements
- No refrigerant leakage risk
- No F-gas servicing requirements for the ventilation unit
- Economical year-round operation
- Continuous fresh-air supply
- Effective removal of odours and airborne contaminants
The system not only controls humidity. It also replaces stale indoor air with fresh outdoor air, improving the overall air quality inside the swimming pool hall.
Simple maintenance and long service life
The DRY X 1200 DUCT has very few moving components. Its main moving parts are the energy-efficient EC fans, which are designed for an expected service life of approximately 10 to 15 years under suitable operating and maintenance conditions.
Regular maintenance primarily consists of:
- Inspecting, cleaning and replacing air filters
- Cleaning the counterflow heat exchanger
- Inspecting the EC fans
- Checking the condensate drainage
- Inspecting the outdoor and indoor air ducts
- Keeping air inlets and outlets unobstructed
The simple mechanical design helps minimise downtime and long-term service costs.
Where can the DRY X 1200 DUCT be used?
The system is designed for ducted dehumidification and ventilation in:
- Private indoor swimming pools
- Hotel swimming pools
- Wellness centres
- Spa facilities
- Therapy pools
- Residential pool halls
- Commercial indoor pool facilities
The DRY X 1200 DUCT ECO is designed primarily for private swimming pools, while the DRY X 1200 DUCT PRO is developed for hotels and demanding commercial wellness environments.
Frequently asked questions
Can outdoor air really dehumidify an indoor swimming pool?
Yes. Outdoor air can dehumidify an indoor pool whenever its absolute humidity is lower than the absolute humidity inside the pool hall. In Central European climates, this occurs during most of the year.
Does the DRY X 1200 DUCT use refrigerant?
No. The standard DRY X 1200 DUCT ventilation unit operates without refrigerant, a compressor or a refrigeration circuit. It dehumidifies through controlled fresh-air ventilation and heat recovery.
Does the system supply 100% fresh air?
Yes. The unit can operate as a 100% fresh-air swimming pool ventilation system, supplying outdoor air and extracting humid indoor air.
What is the typical humidity inside an indoor pool?
A common indoor pool design condition is approximately 30°C and 60% relative humidity, equivalent to around 18.2 g/m³ of absolute humidity.
What happens when the outdoor air is too humid?
When outdoor absolute humidity is equal to or higher than indoor absolute humidity, ventilation alone cannot effectively dehumidify the pool. A Microwell Synairgic combination can provide supplementary dehumidification during these exceptional periods.
Is heat recovered from the extracted pool air?
Yes. A counterflow heat exchanger transfers energy from the warm extracted air to the incoming fresh air, reducing ventilation heat losses and improving energy efficiency.
What maintenance does the unit require?
Regular maintenance mainly includes cleaning or replacing the filters, cleaning the heat exchanger and inspecting the fans, drainage and ductwork.
Fresh air. Low maintenance. Reliable pool climate control.
The Microwell DRY X 1200 DUCT combines swimming pool dehumidification, 100% fresh-air ventilation and heat recovery in one compact system.
It is a quiet, economical and low-maintenance alternative to conventional refrigerant-based dehumidification, with Microwell Synairgic technology available for reliable operation during exceptionally humid conditions.