MSHA(C) ducted dehumidifiers for swimming pools: what they are, how they work, and when they are needed

Imagine this situation: you own a large swimming pool with an area of over 50 m², where condensation constantly appears on the windows, walls are damp, and the air feels heavy. A standard wall-mounted MBA-10G dehumidifier with a capacity of 108 L/day simply cannot cope with that level of evaporation. What to do? The answer is MSHA(C) ducted suspended dehumidifiers with capacities from 28 to 1000 L/day.

Many people believe that a ducted dehumidifier necessarily requires a separate plant room, extra costs, and a complex installation. But that’s a myth! MSHA(C) ducted dehumidifiers can be installed above a suspended ceiling directly in the pool room, if the ceiling height allows (from 3.2 m).

In this article, we will take a detailed look at what ducted dehumidifiers for swimming pools are, how they work, what installation options exist, and which facilities they are best suited for.

What is a ducted dehumidifier: the fundamental difference

Wall-mounted MBA-G vs ducted MSHA(C): two philosophies

Dehumidifiers for swimming pools fall into two fundamentally different types, each with its own installation and operating "philosophy":

Wall-mounted MBA-G is a monoblock installed directly on the wall in the pool room. All equipment is housed in a single casing that is visible in the interior. This dehumidifier draws humid air from the room and returns it already dehumidified. The capacity of wall-mounted models is from 53 to 120 L/day, suitable for pools up to 50 m².

Ducted suspended MSHA(C) is a unit installed out of sight: above the suspended ceiling of the pool room (the main option), in a nearby technical room, in the attic, or in the basement. The dehumidifier is connected to an air duct system and remains completely invisible—the interior shows only grilles in the ceiling or walls. Air is extracted through one duct, dehumidified, and returned through another. The capacity of MSHA(C) ducted models is from 28 to 1000 L/day for pools from 12 to 417 m².

Important to understand: the term "ducted" means the dehumidifier operates via air ducts (channels), but it does not mean it must be placed in a separate room. Visual analogy: a wall-mounted dehumidifier is like a window air conditioner (everything visible on the wall), and a ducted one is like a multi-zone air-conditioning system (hidden above the ceiling).

What a ducted dehumidification system looks like

A ducted dehumidification system consists of the following components:

• The MSHA(C) dehumidifier itself—installed above the ceiling or in a technical room
• Return air duct—extracts humid air from the pool room
• Fresh air duct—a unique feature of MSHA(C), brings in fresh outdoor air
• Supply air duct—returns dry air back to the pool
• Drainage system—for condensate removal
• Control system—a wall-mounted controller in the pool room

Only the supply and return air grilles in the ceiling or walls and a compact controller panel are visible in the pool interior.

How MSHA(C) works: step-by-step process

The operation of the MSHA(C) ducted dehumidifier takes place in several stages:

Step 1: Air intake

The dehumidifier simultaneously handles two air streams:

• Recirculated air from the pool room—humid and warm (70–80% relative humidity)
• Fresh air from outside—which may be cold and dry

Step 2: Filtration

Both air streams pass through three filtration stages:

• G4 filter—captures large particles: dust, hair, insects
• F7 filter—captures medium particles, provides 97% filtration of PM2.5, pollen, spores
• HEPA H13 filter (optional)—medical-grade filtration, captures 99.5% of fine particles, allergens, bacteria

Step 3: Mixing the streams

The two air streams (recirculated and fresh) are mixed. The ratio is regulated by a fresh air damper: typically 60–70% recirculated and 30–40% fresh air.

Step 4: Dehumidification

The mixed air passes through a cold evaporator coil. The air temperature drops below the dew point, moisture condenses and drains away. The air becomes cold and dry.

Step 5: Heating

The cold, dry air passes through a hot condenser coil, where it is heated to a comfortable 28–30°C. At the same time, relative humidity drops to 50–55%.

Step 6: Additional treatment

Optionally, the air undergoes additional treatment:

• UV lamp—kills bacteria, viruses, and mold spores
• Ionizer—enriches the air with negative ions ("air vitamins")

Step 7: Supply back to the room

Dry, warm, cleaned air is supplied through the duct back into the pool room and is evenly distributed through grilles in the ceiling or walls.

Unique MSHA(C) technologies

MSHA(C) ducted dehumidifiers are not just more powerful analogues of wall-mounted models. They are equipped with unique technologies that make them the best choice for large and commercial pools.

Fresh air mixing

The main feature of MSHA(C) is the ability to mix in fresh air from outside. The problem with ordinary dehumidifiers is that they operate only on recirculation: they move the same air in a loop. As a result, CO2 accumulates, chlorine odor persists, there is no oxygen influx, and the air becomes stuffy even at low humidity.

MSHA(C) has two inlets: one for recirculated air and one for outdoor fresh air. A fresh air damper controlled by the controller allows mixing 30–40% fresh air. Thus, the air is constantly renewed, delivering both dehumidification and ventilation at the same time.

Why this is needed:

• Removal of CO2 (especially important for enclosed pools)
• Removal of chlorine vapors
• Oxygen supply
• Improved comfort—fresh air

Three-stage filtration

MSHA(C) is equipped with a powerful filtration system:

• G4+F7—standard configuration, provides basic and medium cleaning, sufficient for most private facilities
• HEPA H13 (option)—medical-grade filtration, captures 99.5% of PM2.5 particles. Critically important for:
  • Asthmatics and allergy sufferers
  • Commercial facilities (responsibility to clients)
  • Children’s pools
  • Rehabilitation centers

UV lamp plus ionizer

To combat the "invisible enemies," MSHA(C) can be equipped with:

• UV lamp—emits UV-C at a wavelength of 253.7 nm, which destroys the DNA of bacteria, viruses, and mold spores. Installed before the HEPA filter, it sterilizes the air before it enters the room. Especially important for preventing legionella (Legionnaires’ disease)
• Ionizer—generates negative ions ("air vitamins") that bind fine particles, making them easier to filter, and give the air a post-thunderstorm freshness

Hydrophobic Blue Coating heat exchanger

The pool environment is aggressive: moisture + chlorine + salts. A standard aluminum heat exchanger corrodes in 2–3 years, and its repair costs 60–70% of a new unit.

MSHA(C) is equipped with heat exchangers featuring a hydrophobic Blue Coating: copper tubes + aluminum fins with coating. This provides corrosion protection and a service life of over 10 years.

Positive-pressure drainage

Unique design: the condensate tray is positioned downstream of the airflow. Air pressure pushes the water into the drain, so water does not stagnate and conditions for bacteria and mold growth are eliminated. The tray material is SUS304 stainless steel (medical grade), which does not rust.

MSHA(C) lineup: eleven models for any facility

Small models — 220 V, single-phase

For large private pools with simple connection to a standard power grid:

Minimum height for installation above a suspended ceiling is 3.2–3.5 m, including clearances.

Medium and large models — 380 V, three-phase

For large private and commercial facilities:

Minimum height for installation above a suspended ceiling is 3.8–4 m. Intended for commercial facilities: hotels, fitness centers, health resorts, and very large private pools.

How to choose a model — quick formula

To correctly select an MSHA(C) model, use a simple formula:

1. Capacity (L/h) = Water surface area (m²) × 0.1
2. Capacity (L/day) = Capacity (L/h) × 24

Example: Pool 10×8 m = 80 m²

80 × 0.1 = 8 L/h

8 × 24 = 192 L/day

You need model MSHA(C)250 (250 L/day) with reserve.

Important: add a 15–20% capacity margin if:

• High water temperature (over 28°C)
• Active daily use (over 4 hours)
• There is a jacuzzi or showers in the same room
• Poor room insulation

Which facilities ducted suspended systems are designed for

Large private pools with high ceilings

Typical facilities:

• High-end villas with high ceilings (3.5–5 m)
• Basement pools with height over 3.5 m
• House extensions with lap pools
• Townhouses with modern architecture

Why ducted suspended?

• Wall-mounted MBA-10G (108 L/day) is not enough
• Aesthetics—you don’t want to see equipment in a premium interior
• There is sufficient height for installation above a suspended ceiling
• No need to allocate a separate room

Recommended models: MSHA(C)100–250

Large private pools without high ceilings but with a plant room

When the room height is under 3.5 m, but the dehumidifier can be placed:

• In the basement (if the pool is on the first floor)
• In the attic/loft (if the pool is on the first floor)
• In an adjacent technical room (boiler room, storage)

Recommended models: MSHA(C)100–250

Commercial pools (hotels, fitness, health resorts)

Specifics:

• High load—dozens of people per day
• Sanitary regulations for air quality
• Responsibility to clients
• 24/7 operation without downtime

Why ducted?

• Capacity 250–1000 L/day
• HEPA filtration to protect clients’ health
• UV sterilization (legionella prevention)
• Fresh air mixing (sanitary code compliance)
• Reliability (commercial-grade equipment)
• Invisibility (professional look)

Installation is usually in a technical room—commercial facilities have the infrastructure. Recommended models: MSHA(C)250–1000.

Sports complexes

Features:

• Large pools (25×10 m, 25×12.5 m)
• High humidity due to intensive use
• Bleachers, locker rooms, many people
• Showers add moisture
• High ceilings (usually 4–6 m)

Installation above the ceiling or in a technical room. Recommended models: MSHA(C)500–1000.

Rehabilitation centers, children’s pools

Critical requirements:

• Maximum air cleanliness (HEPA is mandatory)
• UV sterilization
• Fresh air mixing
• Low chlorine in the air

Recommended models: MSHA(C)180–500, depending on size.

Water parks

For indoor areas with huge evaporation volumes, several MSHA(C)750–1000 dehumidifiers are required, integrated into the general ventilation system and installed in technical rooms.

When a ducted MSHA(C) is justified: decision criteria

By pool size

✓ A ducted unit is needed if the water surface area is over 50 m². The wall-mounted MBA-10G (108 L/day) won’t cope; you need a capacity of over 120 L/day.

✗ A ducted unit is not needed if the area is less than 50 m²—the wall-mounted MBA-G is sufficient. Otherwise, you overpay for equipment and installation.

By ceiling height or availability of a plant room

✓ A ducted unit is possible if at least one of the following is true:

• Option A: the room height allows installation above a suspended ceiling
  • MSHA(C)28–60: ceiling height from 3.2 m
  • MSHA(C)100–140: ceiling height from 3.5 m
  • MSHA(C)180+: ceiling height from 3.8 m
• Option B: there is space to install nearby
  • Technical room (boiler room, storage)
  • Basement (if the pool is on the first floor)
  • Attic, loft (if the pool is on the first floor)
  • Air ducts can be run (distance less than 20 m)

✗ A ducted unit is not suitable if the ceiling height is less than 3.2 m and there is no room nearby, and it is impossible to run ducts (renovation finished, low ceiling, chasing is expensive).

Myth busted: think a ducted unit is impossible because there’s no plant room? Check the height! If it’s over 3.5 m—you can install it above a suspended ceiling.

By aesthetic requirements

✓ Ducted, if:

• Premium interior—you don’t want to see equipment
• Designer project—nothing should stand out
• Commercial facility—professional look, minimalism (only grilles in the ceiling)

! Wall-mounted, if aesthetics are not critical and you are okay with a compact unit on the wall (modern style—equipment as part of the interior).

By budget

Ducted is more expensive:

• Equipment: MSHA(C) is 2–3 times more expensive than an MBA-G of similar capacity
• Installation (ducts, suspended ceiling): 2–4 times more expensive
• Time: 3–7 days of installation versus 2–4 hours for wall-mounted

✓ Ducted is justified if:

• Commercial facility—it pays off by avoiding problems
• Premium property—aesthetics matter more
• Large pool—no alternative (wall units won’t cope)
• You already plan a suspended ceiling—extra costs are minimal

By power supply

• MSHA(C)28–140: 220 V—available in any house, easy connection (for private facilities)
• MSHA(C)180–1000: 380 V—three-phase supply required, more expensive connection (for commercial facilities)

Tip: if the pool is 50–80 m² and only 220 V is available, consider MSHA(C)140 instead of two MBA-10G units.

MSHA(C) installation options: where it can be placed

Option A: above a suspended ceiling

The main choice for private facilities.

Advantages:

• No separate room required
• Short ducts—cheaper installation
• Easy service access via removable panels
• Ideal for new builds—planned from the start

Ceiling height requirements:

Height calculation: minimum room height = dehumidifier height + 300 mm (top clearance) + 200 mm (ceiling thickness) + 2500 mm (clear room height).

What to provide for:

• Suspended ceiling with removable panels for maintenance
• Space for air ducts (usually run in the same ceiling void)
• Drain pipe to the wall or floor
• Power supply
• Ceiling soundproofing (optional) to reduce 35–55 dB to a minimum

Ideal for: new construction, renovation with ceiling replacement, premium villas with high ceilings, private pools 50–100 m².

Option B: in a separate technical room

When to choose this option:

• Ceiling height less than 3.2 m—doesn’t fit above the ceiling
• There is a suitable room nearby (boiler room, storage, utility room)
• Commercial facility (usually has the infrastructure)
• You want to minimize noise in the pool room (the dehumidifier is not audible at all)

Room requirements:

• Area: from 3 m² (MSHA28) to 15 m² (MSHA1000)
• Service access (door at least 80 cm)
• Ventilation (the compressor releases heat)
• Lighting
• Freeze protection in winter (temperature above 10°C)
• Distance to the pool—preferably less than 20 m (duct length)

Advantages:

• Complete noise isolation (35–55 dB remains in the technical room)
• Convenient maintenance (open the door—full access)
• Does not depend on pool ceiling height

Disadvantages:

• A dedicated room is required (not always possible)
• Long ducts—more expensive installation

Option C: in the attic/loft

When suitable: the pool is on the first floor, there is an attic above, the distance to the pool is less than 20 m, ducts run vertically.

Requirements:

• Insulated attic (temperature above 10°C in winter)
• Or use only in the warm season
• Or install a model rated for low-temperature operation

Advantages:

• Use of "dead" space
• Complete noise isolation

Option D: in the basement

When suitable: the pool is on the first floor, there is a basement below, there is access and a possibility to run ducts upward.

Requirements:

• Dry basement (no flooding)
• Ventilation
• Drainage (water must flow by gravity or be pumped up)

Advantages:

• Hidden installation
• Noise isolation

Disadvantage: drainage challenges (water goes down while the drain is often higher—a pump is required).

Comparison of installation options

MSHA(C) vs wall-mounted MBA-G: summary table

Conclusion: MBA-G for 90% of private pools up to 50 m²—simplicity, affordability, sufficient capacity. MSHA(C) for large (over 50 m²) and commercial pools—power, aesthetics, air quality.

FAQ

What is a ducted dehumidifier in simple terms?

It’s a powerful dehumidification system installed out of sight above a suspended ceiling or in a separate room and connected to the pool via air ducts. Only the air supply grilles are visible in the room; the equipment itself is invisible.

Is a separate technical room mandatory?

No, this is a common myth! MSHA(C) can be installed above a suspended ceiling in the pool room if the height allows (from 3.2 m for small models, from 3.5 m for medium ones). A separate room is an alternative, not a requirement.

What ceiling height is required for a ducted dehumidifier?

It depends on the model: MSHA(C)28–60 require 3.2–3.3 m, MSHA(C)100–140 require 3.5 m, MSHA(C)180+ require 3.8–4 m. This includes clearances and the ceiling void.

How is a ducted different from a wall-mounted unit?

The wall-mounted unit hangs on the wall in the room (like an air conditioner), the ducted unit is hidden above the ceiling or in a technical room (air moves through ducts). Ducted units are more powerful (up to 1000 L/day vs 108), offer fresh air mixing, and HEPA filtration.

What pool size requires a ducted unit?

Usually for pools over 50 m² (if less, a wall-mounted MBA-G is sufficient). But there are ducted models even for 12 m² (MSHA28) if aesthetics are critical or fresh air mixing is needed.

What is fresh air mixing in MSHA(C)?

MSHA(C) has two inlets: one draws air from the pool (recirculation, 60–70%), the other—from outdoors (fresh, 30–40%). They are mixed. Result: dehumidification plus constant air renewal, removal of CO2 and chlorine without opening windows.

Can a ducted unit be installed if the renovation is already done?

If the ceiling height allows (over 3.5 m), you can add a suspended ceiling and install the dehumidifier above it. If the ceiling is low, it is technically possible to chase ducts, but it is expensive. It is best to plan at the design stage.

Is HEPA filtration necessary for a pool?

For private pools—optional, for comfort and health (asthma, allergies). For commercial—highly recommended. HEPA H13 removes 99.5% of bacteria, viruses, and allergens. Especially important for children’s pools and rehabilitation centers.

How much does a ducted dehumidifier installation cost?

It depends on the option: installation above a suspended ceiling is cheaper (short ducts), in a separate room is more expensive (long ducts). On average, installation takes 3–7 days, costs 2–4 times more than wall-mounted, but for large pools it’s the only effective solution.

What is the noise level of a ducted dehumidifier?

In the pool room—virtually 0 dB. The dehumidifier generates 35–55 dB, but it is above the ceiling or in a technical room. In the pool you hear only a soft airflow noise from the grilles (like ventilation), about 10–15 dB. You can comfortably stay and even sleep nearby.

What is the advantage of MSHA(C) over other ducted dehumidifiers?

Fresh air mixing (unique technology), three-stage filtration with HEPA, UV lamp + ionizer, hydrophobic Blue Coating heat exchanger, wide lineup (11 models from 28 to 1000 L/day), compact sizes for above-ceiling installation.

Takeaways

MSHA(C) are suspended ducted systems for large and commercial pools with capacities of 28–1000 L/day. Myth busted: a technical room is not mandatory; you can install above a suspended ceiling if the height is over 3.2 m.

Key advantages: capacity 28–1000 L/day, fresh air mixing (unique feature), hidden installation (only grilles visible), HEPA filtration + UV + ionizer. Justified for pools over 50 m² with height over 3.2 m or with a technical room available. The lineup covers pools from 12 to 417 m².

MSHA(C) is the ideal solution for controlling the microclimate of large private and commercial pools. Mycond is a leader in its segment for those seeking a comprehensive, modern, and energy-efficient climate control solution without overpaying for a big-name brand.

Need advice on selecting a dehumidifier for your pool? Contact us via the form on the website or by phone at the bottom of the page, and we will help you choose the optimal solution.