Dantherm CDP40T Through The Wall Dehumidifier – 34L/Day Professional Pool Moisture Control System 🌊

Transform your indoor pool environment with the Dantherm CDP40T, a Danish-engineered through-wall dehumidifier that delivers professional-grade moisture control with exceptional energy efficiency. Designed specifically for swimming pool installations, this unit removes up to 34 litres per day while operating at a whisper-quiet 42dB(A) – quieter than a normal conversation.

The CDP40T solves the persistent problems of indoor pool environments: condensation on windows, musty odours, mould growth, and deteriorating building structures. Unlike portable units, its innovative through-wall design mounts in an adjacent equipment room, keeping noise and heat away from your pool area while delivering powerful, continuous moisture extraction.

Perfect for:

• Residential indoor swimming pools (up to 25m²)
• Spa and therapy pool installations
• Home wellness centres
• Pool equipment rooms
• Fitness facilities with pool areas
• Holiday properties with pools

Key Features & Benefits 🔑

Through-Wall Installation Excellence

Space-saving design allows the unit to be mounted in an adjacent equipment room or garage, with only the air ducts penetrating the wall. This keeps operational noise, heat, and maintenance requirements away from your pool area while maintaining optimal humidity control.

Exceptional Energy Efficiency ⚡

• SEC Rating: 0.47 kWh/L – One of the most efficient pool dehumidifiers available
• R407C refrigerant system – Ozone-friendly and highly effective
• Smart defrost technology – Automatically prevents ice buildup, maintaining peak efficiency
• Annual running cost: Approximately £250-350 based on typical 8-hour daily operation (assuming £0.28/kWh)

Whisper-Quiet Operation 🔇

At just 42dB(A) when operating through-wall (46dB wall-mounted), the CDP40T is quieter than a quiet library. You can enjoy your pool without intrusive mechanical noise disrupting the tranquil atmosphere.

Professional Build Quality 🏗

• Epoxy-coated evaporator and condenser coils – Superior corrosion resistance in chlorinated environments
• Powder-coated metal components – Additional protection against pool chemicals
• Danish engineering by Dantherm – 50+ years of climate control expertise
• IPX4 protection rating – Protected against water splashing from any direction
• 2-year manufacturer warranty (1st year parts & labour, 2nd year parts only)

Intelligent Control System 💡

• Adjustable humidistat (40-99% RH) – Set your ideal comfort level
• Hourly air sampling – Energy-efficient operation only when needed
• LED status indicators – Clear operational feedback
• Temperature safety cut-off – Protects compressor in extreme conditions
• USB data logging – Track performance and efficiency over time
• Modbus RTU communication – Integrate with building management systems

Advanced Features

✅ 10 compressor starts per hour maximum – Protects equipment and extends lifespan
✅ Automatic defrost cycle – Maintains efficiency in cooler conditions
✅ Service interval reminders – Never miss essential maintenance
✅ Run/fail alarm output – Connect to external monitoring systems
✅ Optional wireless remote control – Convenient humidity adjustment from the pool area

Complete Technical Specifications 📊

Dehumidification Performance

Specification	Value
Dehumidification Capacity	34 litres/day (1.4 L/hr)
Operating Conditions	30°C air @ 60% RH, 28°C pool water
Airflow Rate	400 m³/hour
Operating Temperature Range	10°C to 36°C
Operating Humidity Range	40% to 100% RH
Humidity Control Accuracy	±2% RH (with hysteresis)
Heat Output to Pool Room	1.62 kW

Electrical Specifications

Specification	Value
Power Supply	230V / 1-phase / 50Hz
Nominal Power Consumption	0.9 kW
Maximum Current Draw	3.8 Amps
Recommended Fuse Rating	10 Amp (motor-rated)
SEC Energy Rating	0.47 kWh/L @ 28°C / 60% RH
Protection Class	IPX4 (splash-proof)

Refrigeration System

Specification	Value
Refrigerant Type	R407C (ozone-friendly)
Refrigerant Charge	0.7 kg
Global Warming Potential (GWP)	1774
Compressor Type	Permanent lubrication (maintenance-free)
Defrost System	Automatic hot gas defrost

Physical Specifications

Specification	Value
Width (Unit)	998 mm
Height (Unit)	700 mm
Depth (Unit)	304 mm
Wall Opening Required	610 mm (W) × 395 mm (H)
Weight	57.5 kg
Condensate Drain Connection	3/4″ BSP
Sound Pressure Level	42 dB(A) @ 1 metre (through-wall)
Air Filter Type	PPI 15 foam filter (washable)

Installation Specifications

Specification	Value
Minimum Clearance to Ceiling	225 mm
Minimum Clearance to Floor	225 mm
Drainage Fall Required	Minimum 2% gradient
Wall Thickness Suitable	200-400 mm (with extension kits available)
Mounting Method	Wall suspension bar (supplied)

Room Size & Capacity Recommendations 🏊

Suitable Pool Room Volumes

The CDP40T is ideally suited for the following pool environments:

Pool Surface Area	Pool Room Volume	Room Dimensions (Example)	Humidity Load
15-20 m²	50-70 m³	5m × 4m × 3m ceiling	Light to moderate
20-25 m²	70-90 m³	6m × 4m × 3.5m ceiling	Moderate
Up to 25 m²	Up to 95 m³	7m × 4.5m × 3m ceiling	Moderate to heavy

Important Factors Affecting Performance:

• Pool temperature: Higher temperatures = more evaporation
• Pool usage: More swimmers = more humidity
• Room ventilation: Draughts reduce efficiency
• Insulation quality: Poor insulation = higher humidity loads
• Pool cover usage: Covers dramatically reduce evaporation when pool not in use

💡 Pro Tip: For pools larger than 25m² or with heavy usage (6+ hours daily), consider upgrading to the CDP50T (52L/day) or CDP70T (69L/day) models for optimal humidity control.

Real-World Dehumidification Performance ⏱

Estimated Moisture Extraction Times

These estimates show how long the CDP40T takes to reduce humidity in typical pool rooms:

Starting Conditions: 80% RH, targeting 60% RH (recommended for pool rooms)

Room Volume	Approximate Time to Target	Notes
50 m³	3-5 hours	Small residential pool
70 m³	5-7 hours	Medium residential pool
90 m³	7-10 hours	Larger residential pool

⚠ Important Disclaimers:

• Times are estimates based on sealed room with 30°C air temperature and typical pool conditions
• Actual performance varies with air temperature, starting humidity, pool temperature, room ventilation, and external conditions
• Best results achieved with doors/windows closed and pool covered when not in use
• Initial dehumidification may take longer; maintenance cycle times will be shorter

Daily Moisture Load Comparison

Scenario	Daily Evaporation	CDP40T Coverage
Small pool, covered overnight	20-25 litres/day	✅ Excellent
Medium pool, moderate use	28-32 litres/day	✅ Very Good
Large pool, heavy use, uncovered	35-45 litres/day	⚠ Consider CDP50T

Pool Room Optimization Guide 🎯

Achieving Optimal Performance

Recommended Humidity Setpoint: 50-60% RH
Recommended Temperature: 28-30°C (2-3°C above pool water temperature)

Maximum Efficiency Checklist

✅ Install pool cover – Reduces evaporation by 60-90% when pool not in use
✅ Seal room properly – Eliminate draughts from doors, windows, and ceiling
✅ Insulate cold surfaces – Prevents condensation on windows and walls
✅ Position unit correctly – Equipment room installation ideal for through-wall model
✅ Regular filter cleaning – Monthly cleaning maintains airflow efficiency
✅ Annual professional service – Keeps system operating at peak performance
✅ Monitor water chemistry – Maintain proper pH and chlorine levels (see manual)

Running Cost Analysis 💰

Electricity Consumption Estimates:

Usage Pattern	Daily Runtime	Monthly kWh	Monthly Cost*	Annual Cost*
Light use (covered pool)	4-6 hours	108-162 kWh	£30-45	£360-540
Moderate use	6-8 hours	162-216 kWh	£45-60	£540-720
Heavy use (busy pool)	8-12 hours	216-324 kWh	£60-90	£720-1,080

*Based on £0.28/kWh (UK average 2024). Your costs may vary based on tariff.

Energy Saving Tips: 💡 Use a timer for off-peak operation (lower electricity rates)
💡 Cover pool religiously when not in use
💡 Lower room temperature slightly (every 1°C reduction = ~5% energy saving)
💡 Clean filter monthly for optimal airflow efficiency
💡 Ensure proper drainage gradient to prevent pump strain

📄 Downloads & Technical Documentation

Complete Product Information

📄 Dantherm CDP Service Manual (opens in new tab)
Comprehensive 38-page technical manual covering installation procedures, electrical connections, control panel operation, maintenance schedules, troubleshooting guides, wiring diagrams, and spare parts identification. Essential reading for installers and service engineers.

📄 CDP Dehumidifier Product Brochure (opens in new tab)
Official manufacturer brochure with complete specifications, dimensions, performance data, accessory options, and installation requirements for the entire CDP range including wall-mounted and through-wall models.

Installation Requirements 🔧

Pre-Installation Checklist

Wall Requirements:

• Wall thickness: 200-400mm (extension kits available for thicker walls)
• Wall opening: 610mm (W) × 395mm (H)
• Structural support: Wall must support 60kg unit weight
• Adjacent room: Must be heated to at least 10°C

Electrical Requirements:

• 230V mains supply with proper earthing
• 10A motor-rated fuse or MCB
• 2.5mm² cable minimum (as per UK wiring regulations)
• Dedicated circuit recommended for optimal performance

Drainage Requirements:

• 3/4″ flexible drain hose to suitable drainage point
• Minimum 2% fall (2cm drop per 1m run)
• Alternative: condensate pump if gravity drainage not possible
• Drainage must not freeze in winter

Clearance Requirements:

• Minimum 225mm clearance above unit (air circulation)
• Minimum 225mm clearance below unit (service access)
• Unobstructed air path from pool room through wall opening

Installation Process Overview

1. Mark and cut wall opening (610mm × 395mm)
2. Install CDP-T wall duct (included) for professional finish
3. Mount wall suspension bar horizontally (critical for drainage)
4. Attach wall mounting spacers to rear of unit
5. Connect 3/4″ drainage hose with 2% minimum fall
6. Hang unit on wall suspension bar
7. Make electrical connection (by qualified electrician)
8. Commission unit and set humidity control parameters

⚠ Professional Installation Recommended: While technically capable DIYers can install this unit, we strongly recommend professional installation by a qualified HVAC technician and electrician to ensure optimal performance, safety, and warranty compliance.

Water Chemistry Requirements for Pool Dehumidifiers 🧪

⚠ CRITICAL: Incorrect pool water chemistry can void your warranty and destroy the dehumidifier in months. The CDP40T is designed to withstand normal chlorinated pool environments when water chemistry is properly maintained.

Mandatory Water Chemistry Parameters

For Chemically Treated Pools:

Parameter	Required Range	Notes
Free Chlorine	1.0 – 2.0 ppm	Must not exceed 2.0 ppm
Combined Chlorine	Max 1/3 of free chlorine	Indicates poor water quality if higher
pH Level	7.2 – 7.6	Critical for equipment protection
Total Alkalinity	80 – 150 ppm	Buffers pH changes
Calcium Hardness	250 – 450 ppm	Prevents corrosion
Total Dissolved Solids	< 2,000 ppm	Higher levels are corrosive
Sulphates	< 360 ppm	Corrosive at higher levels

For Salt Chlorinator Pools:

Parameter	Required Range	Notes
Salt (NaCl)	< 30,000 ppm	Standard salt pools use 3,000-5,000 ppm
Total Dissolved Solids	< 5,500 ppm	Higher than chemical pools
pH Level	7.2 – 7.6	Same as chemical pools
Total Alkalinity	80 – 150 ppm	Same as chemical pools
Calcium Hardness	250 – 450 ppm	Same as chemical pools
Sulphates	< 360 ppm	Same as chemical pools

💡 Use the Langelier Saturation Index to verify that your water chemistry parameters work together harmoniously. Contact Dantherm or your pool specialist if you need assistance with water balancing.

⚠ Warranty Note: Failure to maintain water chemistry within these parameters will void the manufacturer warranty. Corrosion damage from poor water chemistry is not covered under warranty.

Maintenance Schedule & Service Requirements 🛠

Monthly Maintenance (User-Serviceable)

Air Filter Cleaning (30 minutes)

1. Switch off dehumidifier power
2. Remove front cover (2 screws at bottom)
3. Remove PPI 15 foam filter from rear of cover
4. Wash in warm soapy water OR vacuum clean thoroughly
5. Allow to dry completely before reinstalling
6. Refit cover and restore power

Drip Tray & Drainage Inspection (15 minutes)

• Check drip tray for debris or algae buildup
• Verify drainage is flowing freely
• Clean drain hose if flow appears reduced

Annual Professional Service (Required)

Comprehensive Inspection (by qualified technician):

• Remove and vacuum clean condenser coils thoroughly
• Inspect evaporator for dirt buildup and clean if needed
• Check all electrical connections for corrosion
• Verify refrigerant charge and system pressures
• Test all sensors (temperature, humidity, pressure)
• Inspect and clean defrost valve operation
• Check compressor operation and start capacitor
• Verify control board functionality and update firmware if needed
• Test run/fail alarm outputs if connected
• Clean or replace air filter
• Inspect wall duct seals and insulation

💡 Service Interval Reminder: The CDP40T features a built-in service timer that displays “SEr” when annual service is due. This can be set from 1-99 weeks in the control panel menu.

Replacement Parts & Consumables

Component	Expected Life	Part Number
Air Filter (PPI 15)	2-3 years	094686
Humidity/Temperature Sensor	5-7 years	Contact dealer
PCB Main Board	10+ years	Contact dealer
Compressor	10-15 years	Contact dealer

🔧 Spare Parts: Available through authorized Dantherm dealers. Reference the Service Manual (page 34) for complete spare parts identification and part numbers.

Frequently Asked Questions (FAQs) ❓

Installation & Setup Questions

Q: Can I install this unit myself?
A: While mechanically capable DIYers can handle the wall opening and mounting, we strongly recommend professional installation. Electrical work must be completed by a qualified electrician, and improper installation can void your warranty. HVAC technicians will ensure optimal placement, proper drainage, correct electrical connections, and initial commissioning.

Q: What thickness wall can the CDP40T be installed through?
A: The standard CDP40T through-wall duct kit is designed for walls between 200-400mm thick. For thicker walls, extension kits are available as accessories. The wall must be structurally sound enough to support the 57.5kg unit weight.

Q: Does the unit need to be installed in a heated space?
A: Yes, the equipment room where the unit is mounted must be heated to a minimum of 10°C. The unit’s operating range is 10-36°C. Installing in an unheated garage or outbuilding in winter may cause the unit to shut down or operate inefficiently.

Q: How much noise will I hear in the pool room?
A: With through-wall installation, most operational noise (compressor, fan motor) stays in the equipment room. The pool room typically experiences only subtle air movement sound, making this configuration ideal for maintaining a peaceful pool environment. The unit measures just 42dB(A) at 1 meter, which is quieter than a normal conversation.

Operation & Performance Questions

Q: How long does it take to dehumidify my pool room initially?
A: Initial dehumidification of a damp pool room (80% RH down to 60% RH) typically takes 6-12 hours for a 70m³ room, depending on starting conditions, temperature, and how well sealed the room is. Once the target humidity is reached, the unit will cycle on/off to maintain that level, typically running 4-8 hours per day.

Q: Will this unit heat my pool room?
A: The CDP40T provides 1.62kW of heat as a byproduct of the dehumidification process, which helps offset heating costs. The air returned to the pool room is approximately 5°C warmer than the intake air. However, this unit is NOT a primary heating system. For dedicated temperature control, optional LPHW (low pressure hot water) or electric heating coils can be added.

Q: What humidity level should I set for my pool room?
A: We recommend setting the humidistat to 50-60% RH for optimal comfort and equipment protection. Below 50% can feel uncomfortably dry and increase evaporation; above 65% risks condensation on windows and walls. The factory default is 60% RH, which works well for most installations.

Q: How does the automatic defrost system work?
A: The CDP40T monitors evaporator coil temperature constantly. When the coil temperature drops below a preset threshold (typically below 5°C) for a sustained period, the unit automatically switches to defrost mode. It stops the fans, opens the magnetic valve, and redirects hot refrigerant gas through the evaporator to melt any ice. Once the coil warms up, normal dehumidification resumes. This is completely automatic and requires no user intervention.

Q: Why does the unit stop and start throughout the day?
A: This is normal operation. The CDP40T has an intelligent humidity sampling system: when humidity falls below your setpoint, the unit stops dehumidifying. Once per hour, it runs the fan for one minute to sample the room air. If humidity has risen above setpoint, it restarts; if not, it remains off. This “smart cycling” dramatically reduces energy consumption compared to units that run continuously.

Maintenance & Troubleshooting Questions

Q: How often do I need to clean the air filter?
A: Monthly cleaning is recommended for optimal performance, especially in pools with heavy use. Simply remove the front cover (2 screws), pull out the foam filter, wash in warm soapy water or vacuum clean, let dry completely, and reinstall. More frequent cleaning may be needed if you notice reduced airflow or if the room has high dust levels.

Q: The display shows “SEr” – what does this mean?
A: This is the service interval reminder indicating that annual professional service is due. The unit will continue operating normally, but you should schedule service with a qualified HVAC technician soon. After service, the technician will reset the service timer in the control menu.

Q: Why is there water dripping from the unit?
A: Check these common causes: (1) Blocked or kinked drain hose preventing water from flowing away, (2) Insufficient drainage gradient – needs minimum 2% fall, (3) Blocked drip tray or drain spigot – clean thoroughly, (4) Frozen drain line if installed in cold space. If the wall installation isn’t level, this can also cause drainage issues.

Q: The LED is flashing red – what’s wrong?
A: Firmware v1.47 uses different LED patterns to indicate issues: 2× red flash = Low Pressure alarm (refrigerant leak or expansion valve problem), 4× red flash = High Pressure alarm (overheating, blocked condenser), 6× red flash = Sensor fault (temperature or humidity sensor malfunction). Consult the troubleshooting guide in the Service Manual (pages 27-32) or contact a qualified service technician.

Energy & Running Costs Questions

Q: How much does it cost to run per year?
A: Based on moderate use (6-8 hours daily) at current UK electricity rates (£0.28/kWh), expect £540-720 per year. This varies significantly based on pool usage, room size, how well sealed the room is, and whether you use a pool cover. Using a cover when the pool isn’t in use can reduce running costs by 30-50%.

Q: Is this unit energy efficient?
A: Yes, very. The CDP40T has an SEC (Specific Energy Consumption) rating of 0.47 kWh/L, making it one of the most efficient pool dehumidifiers on the market. The R407C refrigerant system, smart cycling controls, and high-efficiency compressor all contribute to low running costs compared to older or budget dehumidifiers.

Q: Can I use a timer to run it during off-peak hours?
A: Yes, this is an excellent way to reduce running costs if you have a time-of-use electricity tariff. Set a timer to run the unit during cheaper rate periods (typically overnight). However, ensure the unit still runs enough hours to control humidity effectively – you may need some daytime operation during heavy pool use periods.

Compatibility & Integration Questions

Q: Can I control this unit remotely?
A: Yes, the optional DRC1 wireless remote control accessory allows you to adjust humidity settings from inside the pool room without accessing the equipment room. The unit also supports Modbus RTU communication for integration with Building Management Systems (BMS), allowing remote monitoring and control via computer networks.

Q: Can I add a heating coil later?
A: Yes, the CDP40T can be retrofitted with either LPHW (low pressure hot water) heating coils or electric heating coils as optional accessories. These are controlled through the dehumidifier’s built-in temperature control function. This upgrade provides automatic temperature control alongside humidity control. Consult the installation manual and your heating engineer for specification and compatibility.

Q: Does this work with salt water pools?
A: Yes, but with stricter water chemistry requirements. Salt water pools must maintain salt levels below 30,000 ppm (standard pools use 3,000-5,000 ppm) and keep Total Dissolved Solids below 5,500 ppm. All other parameters (pH, alkalinity, calcium hardness) remain the same. Proper water chemistry is even more critical with salt systems to prevent accelerated corrosion.

Q: Can I connect an external humidity sensor?
A: Yes, the CDP40T has terminals for an optional external RH/temperature sensor. This is useful if your equipment room installation means the internal sensor isn’t reading pool room conditions accurately. The external sensor overrides the internal sensor when connected and enabled via a switch on the control board.

Optional Accessories & Upgrades 🔌

Enhance your CDP40T with these manufacturer-approved accessories:

DRC1 Wireless Remote Control
Adjust humidity settings from the comfort of your pool room without walking to the equipment room. Battery-operated with RF communication.

Floor Mounting Kit
For installations where wall mounting isn’t practical or when floor-standing configuration is preferred.

LPHW Air Heating Coil + Control Valve
Integrates with your boiler system to provide 3.32kW additional heating output. Automatically maintains room temperature while the CDP40T controls humidity. Requires 12mm boiler connections and 4.2 L/min flow rate.

Electric Heating Coil (2kW)
Alternative heating solution that doesn’t require boiler integration. Provides 2kW additional heat output for total 2.66kW heating capacity. Requires upgraded electrical supply (20A circuit).

Through-Wall Duct Extension Kit
For wall thicknesses exceeding 400mm. Includes additional duct sections, seals, and mounting hardware.

Aluminum Grille Kit
Attractive satin finish grilles for pool room side of through-wall installation. Improves aesthetics while protecting the air openings.

Condensate Pump
For installations where gravity drainage isn’t possible. Pumps condensate water upward to a suitable drainage point.

What’s Included in the Box 📦

✅ Dantherm CDP40T dehumidifier unit
✅ Wall suspension mounting bar
✅ Wall mounting spacers (2×)
✅ CDP-T through-wall duct with filter
✅ Condensate drain spigot (3/4″ BSP)
✅ User control panel and display
✅ Installation instruction manual
✅ USB data logging capability
✅ 2-year manufacturer warranty (1st year parts & labour, 2nd year parts)

Not Included (Purchase Separately):

• Drainage hose and fittings
• Electrical cable and connection materials
• Wall mounting fixings (wall-dependent)
• Optional accessories (remote control, heating coils, etc.)

Why Buy From Parts4Tubs? 🏆

✅ Authorized Dantherm Dealer – Full manufacturer warranty support
✅ UK Stock – Fast dispatch and delivery
✅ Expert Technical Support – Help with sizing, installation questions, and troubleshooting
✅ Competitive Pricing – Professional equipment at fair prices
✅ Genuine Parts – Factory-original components and accessories
✅ Installation Referrals – We can recommend qualified installers in your area

Warranty Information 📋

2-Year Manufacturer Warranty:

• First Year: Parts AND labour coverage
• Second Year: Parts only coverage

Warranty Conditions:

• Professional installation required
• Water chemistry parameters must be maintained within specified ranges (see manual)
• Regular maintenance (monthly filter cleaning, annual professional service)
• Registration required within 30 days of installation
• Proof of purchase and installation date required for claims

Not Covered:

• Damage from improper water chemistry
• Damage from incorrect installation or unauthorized modifications
• Failure to perform required maintenance
• Normal wear items (filters, consumables)
• Electrical damage from improper supply or lightning strikes

Order Your CDP40T Today 🛒

Transform your indoor pool environment with professional-grade humidity control. The Dantherm CDP40T delivers whisper-quiet, energy-efficient operation with the reliability you expect from Danish engineering.

Need help with sizing or installation? Contact our technical team for expert advice on selecting the right dehumidifier for your specific pool room dimensions and usage patterns.

Ready to order? Add to cart now for fast UK dispatch. Full manufacturer warranty and technical support included.