💨 Monitair 75 Pool Dehumidifier with Defrost & LPHW Air Heating (1 Phase) | DH75AX/L

Professional Climate Control for Indoor Swimming Pools

Transform your indoor pool environment with the Monitair 75 DH75AX/L – a powerful dehumidifier that doesn’t just remove moisture, it converts the energy locked in water vapor into usable heat. Perfect for domestic pools, therapy centers, health clubs, and hotel & spa facilities, this sophisticated unit combines exceptional dehumidification with LPHW (Low Pressure Hot Water) air heating to deliver complete climate control year-round.

Why Indoor Pools Need Professional Dehumidification

Even when you can’t see it, moisture in the form of water vapor surrounds your indoor pool. Left uncontrolled, this humidity causes devastating corrosion, mold growth, bacteria proliferation, and major structural damage to your pool building. The Monitair 75 protects your investment while creating a comfortable, safe environment for swimmers.

🌟 Key Features & Benefits

✅ Exceptional Dehumidification Performance Removes up to 86.4 liters of moisture per day (3.6 L/hr), effectively controlling humidity in medium to large indoor pool halls while preventing structural damage and health issues.

✅ Energy Recovery Technology Cleverly recovers the latent heat energy contained in moisture and delivers it back to your pool hall as 4.7 kW of free heat – reducing your heating bills and keeping your boiler off for longer.

✅ Dual Climate Control with LPHW Air Heating Integrated LPHW (Low Pressure Hot Water) heating adds an additional 8.9 kW of air heating capacity, providing a total heat output of 11.3 kW to maintain comfortable temperatures year-round without separate heaters or radiators.

✅ Built-In Defrost System Standard defrost functionality ensures consistent performance even in challenging conditions down to 5°C, making it suitable for year-round operation in UK climates.

✅ Flexible Installation Options Available as wall-mounted or through-the-wall (TTW) models – perfect for installations where the unit needs to be positioned in an adjacent plant room for aesthetic or space reasons.

✅ Energy Efficient Operation Consumes just 1.46 kW of power while delivering over 11 kW of heating – an impressive efficiency ratio that dramatically reduces running costs compared to conventional heating and ventilation systems.

✅ Quiet Operation Operates at just 48.5 dB(A) at 3 meters – quieter than normal conversation, ensuring a peaceful pool environment.

📊 Complete Technical Specifications

Dehumidification Performance

Specification	Value
Model Number	DH75AX/L
Dehumidification Capacity	3.6 L/hr (86.4 L/day)
Performance Test Conditions	Air @ 30°C / 60% RH, Pool Water @ 28°C
Air Flow Rate	1,180 m³/hr
Condensate Drain Size	15mm

Heating Performance

Specification	Value
Heat Recovery Output	4.7 kW
LPHW Air Heating Output	8.9 kW @ 80°C
Total Heat to Air	11.3 kW (combined)
LPHW Flow Rate	9.6 L/min
LPHW Pressure Drop	2.8 m head
LPHW Connection Size	22mm copper stub

Electrical Requirements

Specification	Value
Electrical Supply	230V / 50Hz (Single Phase)
Nominal Power Consumption	1.46 kW
Nominal Running Current	6.4 Amps
Full Load Amps (FLA)	7.8 Amps
Compressor LRA	55 Amps
Required Fuse Rating	13 Amp (motor rated)

Physical Dimensions & Weight

Wall Mount Model:

Dimension	Measurement
Width	1,520 mm
Height	796 mm
Depth	385 mm
Weight (Unpacked)	153 kg

Through-The-Wall (TTW) Model:

Dimension	Measurement
Width	1,474 mm
Height	1,167 mm (to top duct)
Depth	350 mm
Weight (Unpacked)	153 kg

Environmental & Refrigerant Data

Specification	Value
Noise Level	48.5 dB(A) @ 3m
Refrigerant Type	R407C (ozone-friendly)
Operating Temperature Range	Down to 5°C (with defrost)
Humidistat Range	Adjustable 20% to 80% RH

🏊 Pool Size Suitability Guide

The Monitair 75 is designed for medium to large indoor pool installations. Use this guide to determine suitability for your facility:

Recommended Pool Hall Volumes

Pool Type	Approximate Hall Volume	Suitability
Small Domestic Pool	Up to 150 m³	✅ Excellent
Medium Domestic Pool	150 – 300 m³	✅ Excellent
Large Domestic Pool	300 – 450 m³	✅ Good
Small Commercial Pool	450 – 600 m³	⚠️ Adequate*
Therapy Pool / Health Club	Varies	✅ Excellent

*For larger commercial applications, consider the Monitair 110 or multiple units.

Pool Water Volume Examples

Pool Dimensions	Volume (m³)	Volume (Gallons)	Recommended Model
6m x 3m x 1.5m	27 m³	5,940 gal	✅ Monitair 75
8m x 4m x 1.5m	48 m³	10,560 gal	✅ Monitair 75
10m x 5m x 1.5m	75 m³	16,500 gal	✅ Monitair 75
12m x 6m x 1.5m	108 m³	23,760 gal	⚠️ Consider Monitair 110

💰 Running Cost Comparison

The Monitair 75’s heat recovery technology delivers significant savings compared to alternative climate control methods:

Annual Operating Cost Estimates*

System Type	Est. Annual Cost	Heat Recovery Benefit
Monitair 75 (Heat Recovery)	£850 – £1,200	Baseline
Ventilation Only (No Recovery)	£2,400 – £3,200	❌ 2-3x more expensive
Separate Dehumidifier + Heaters	£1,800 – £2,500	❌ 1.5-2x more expensive
No Climate Control	Variable	⚠️ Risk of £10,000+ structural damage

*Estimates based on typical 8m x 4m domestic pool, 8-hour daily use, average UK energy prices (£0.28/kWh). Actual costs vary by usage, insulation, and local rates.

Energy Efficiency Benefits

✅ Recovers 4.7 kW of “free” heat from moisture removal ✅ Reduces evaporation from pool surface by maintaining optimal humidity ✅ Keeps boiler off longer through efficient heat recovery ✅ Eliminates need for separate fan heaters or radiators ✅ Lowers overall heating demand by up to 40% vs. conventional ventilation

⏱️ Dehumidification Performance Estimates

Time to Achieve Target Humidity Levels

These estimates show how quickly the Monitair 75 can bring humidity under control in various pool hall sizes:

Starting Condition: 70% RH at 30°C Target Condition: 55% RH at 30°C

Pool Hall Volume	Est. Time to Target	Daily Moisture Removal
150 m³	6-8 hours	Up to 86 liters
250 m³	10-14 hours	Up to 86 liters
350 m³	14-18 hours	Up to 86 liters
450 m³	18-24 hours	Up to 86 liters

⚠️ Important Disclaimers:

• Times are estimates based on typical conditions
• Actual performance varies by temperature, existing RH%, pool cover usage, bather load, and ventilation
• Initial dehumidification takes longer; maintenance cycles are shorter
• Pool covers can reduce moisture load by 50-60% when not in use
• These figures assume the unit runs continuously

🛠️ Installation Requirements & Clearances

Electrical Installation

• Qualified electrician required for all electrical work
• Dedicated circuit with 13 amp motor-rated fuse required
• Unit must be earthed in accordance with IEE Wiring Regulations
• Electrical supply: 230V / 50Hz single phase
• Consider surge protection in areas prone to power fluctuations

LPHW (Heating) Connections

• 22mm copper stub connections for flow and return
• Boiler output recommendation: 9.6 kW minimum (for heating function)
• LPHW supply temperature: 80°C optimal
• Motorized 3-way valve built into unit for automatic control
• Separate air thermostat required (supplied with unit)
• Professional plumbing installation required

Condensate Drainage

• 15mm condensate drain connection required
• Must gravity drain to waste with adequate fall (minimum 1:40 gradient)
• Condensate trap recommended to prevent odors
• Drainage rate: Up to 3.6 liters per hour under maximum load

Physical Clearances & Space Requirements

Wall Mount Installation:

Clearance	Minimum Space
Front Access	1,000 mm (for filter maintenance)
Side Clearances	300 mm each side (for air circulation)
Top Clearance	500 mm (for air discharge)
Mounting Height	Floor level to 2m high recommended

Through-The-Wall Installation:

• Wall thickness: Suitable for standard UK cavity walls (275-300mm)
• Hole dimensions: 892mm x 984mm (viewed from plant room)
• Must seal wall cavity around installation to prevent air recirculation
• Supplied with decorative grilles for pool hall side
• Plant room side requires adequate ventilation

Ventilation Requirements (Plant Room)

If installing TTW model in plant room:

• Minimum ventilation: 2 air changes per hour
• Ensure adequate makeup air for proper operation
• Consider heat buildup in summer months

🎯 Ideal Applications

✅ Perfect For:

🏡 Domestic Indoor Pools

• Home pools up to 10m x 5m
• Garden room pool enclosures
• Pool houses and converted outbuildings
• Basement swimming pools

💆 Therapy & Wellness Centers

• Hydrotherapy pools
• Rehabilitation facilities
• Physiotherapy pool environments
• Medical therapy centers

🏨 Hospitality & Leisure

• Hotel pool facilities
• Spa & wellness centers
• Guest house amenities
• Boutique hotel pools

🏋️ Small Health Clubs

• Gym swimming pools
• Fitness center amenities
• Sports club facilities
• Community leisure centers

🔧 What’s Included

When you order the Monitair 75 DH75AX/L, you receive:

✅ Monitair 75 dehumidifier unit (DH75AX/L model with LPHW heating) ✅ Integrated LPHW heating battery ✅ Built-in motorized 3-way valve for heating control ✅ Wall-mounted air thermostat (PG2000A) ✅ Adjustable humidistat (20-80% RH range) ✅ 22mm LPHW copper stub connections ✅ 15mm condensate drain connection ✅ Installation manual and technical documentation ✅ 2-year manufacturer’s parts and labor warranty

For TTW Models (Through-The-Wall), also includes: ✅ Decorative inlet and outlet grilles for pool hall ✅ Full wall mounting brackets ✅ Duct sleeve kit

NOT Included (Available Separately): ❌ Electrical wiring and isolation switch ❌ Condensate drainage pipework ❌ LPHW pipework and boiler connections ❌ Wall penetration work (for TTW models)

❓ Frequently Asked Questions

Q: What size pool is the Monitair 75 suitable for? A: The Monitair 75 is ideal for domestic pools up to approximately 10m x 5m (50 m²) and pool halls up to 450 m³ volume. For larger commercial pools, consider the Monitair 110 or consult with our technical team for multi-unit installations.

Q: Can I use this without the LPHW heating function? A: Yes, but this model (DH75AX/L) comes with integrated LPHW heating as standard. If you don’t need air heating, consider the DH75AX model (without /L designation), which offers dehumidification only with heat recovery at a lower cost.

Q: How much does it cost to run per year? A: Based on typical domestic pool usage (8 hours daily), expect annual running costs of £850-£1,200 at current UK energy prices (£0.28/kWh). The heat recovery feature significantly reduces this compared to conventional ventilation systems, which can cost 2-3x more annually.

Q: How loud is the unit during operation? A: The Monitair 75 operates at 48.5 dB(A) at 3 meters distance – roughly equivalent to a quiet conversation or library ambiance. It’s designed to provide climate control without disrupting the peaceful pool environment.

Q: Do I need a boiler for this unit to work? A: The dehumidification function works independently without a boiler. However, to utilize the LPHW air heating feature (which provides the additional 8.9 kW of warmth), you’ll need a boiler supplying hot water at 80°C. The unit includes a built-in motorized valve for automatic control.

Q: What maintenance does the Monitair 75 require? A: Regular maintenance is straightforward: Clean washable filters monthly (located behind access panels), check condensate drainage quarterly, annual professional service recommended for refrigerant system and electrical connections. The unit is designed for long-term reliability with minimal intervention.

Q: Can this be installed in a plant room away from the pool? A: Absolutely! That’s what the Through-The-Wall (TTW) variant is designed for. The DH75AX/TL model mounts in an adjacent plant room with decorative grilles on the pool hall side, keeping noise and equipment out of sight while still providing effective climate control.

Q: Will this eliminate condensation on windows? A: The Monitair 75 dramatically reduces condensation risk by controlling humidity levels (typically 55-60% RH). However, glazing condensation also depends on glass quality (double/triple glazing recommended), external temperatures, and warm air distribution. For best results, combine with proper glazing and direct warm air toward windows.

Q: How does heat recovery work? A: The unit extracts moisture from warm, humid air. During dehumidification, the energy (heat) locked in that water vapor is recovered via the refrigeration cycle and released back into the pool hall as warm, dry air. This “free” heat (4.7 kW) reduces your overall heating demand significantly.

Q: What’s the difference between wall mount and through-the-wall models? A: Wall mount units are installed directly in the pool hall, visible but sleek. Through-the-wall (TTW) models are positioned in an adjacent plant room with only decorative grilles visible in the pool hall – ideal for aesthetic installations or where space is limited in the pool area.

Q: Is installation included in the price? A: Installation is not included. Professional installation by qualified electricians and plumbers is required. We recommend using installers experienced with pool dehumidification systems for optimal performance and warranty compliance.

Q: What warranty coverage is included? A: The Monitair 75 includes a comprehensive 2-year manufacturer’s parts and labor warranty, supported by a nationwide network of Certikin-approved service engineers. Extended warranty options may be available – please inquire.

📄 Downloads & Technical Documentation

Access complete product specifications, installation guides, and pool hall design resources:

📥 Product Technical Documents

📄 Monitair 110 Technical Datasheet (opens in new tab) Complete technical specifications, dimensions, performance data, and installation diagrams for the Monitair range. Includes electrical requirements, LPHW connections, and through-the-wall installation details.

📄 Vaporex & Monitair Product Brochure 2022 (opens in new tab) Comprehensive product catalog featuring the complete Calorex dehumidifier range, including detailed comparison tables, performance charts, feature descriptions, and application guidance for domestic and commercial pools.

📄 Guidelines to Pool Hall Construction 2022 (opens in new tab) Essential reference guide covering pool hall design considerations, structural requirements, insulation specifications, vapor barrier installation, condensation prevention, and building regulation compliance for indoor pool facilities.

🛡️ Why Choose the Monitair 75?

Protect Your Investment

Indoor pool buildings are significant investments that require proper environmental control. Without effective dehumidification, moisture causes:

⚠️ Structural steel corrosion – Costly repairs or replacement ⚠️ Timber rot and decay – Compromised structural integrity ⚠️ Mold and bacteria growth – Health hazards and remediation costs ⚠️ Paint and finish deterioration – Ongoing maintenance expenses ⚠️ Condensation damage – Water staining and material degradation

The Monitair 75 prevents these issues, protecting your pool building and ensuring a safe, comfortable environment for decades to come.

Energy Efficiency That Pays for Itself

Traditional ventilation systems heat cold outdoor air and exhaust warm indoor air – wasting massive amounts of energy. The Monitair 75’s heat recovery technology captures that energy, converting moisture removal into useful heat. Over time, the energy savings substantially offset the initial investment.

Professional-Grade Performance for Residential Budgets

Engineered by Calorex (Certikin), a leading manufacturer of pool environmental systems, the Monitair 75 brings commercial-grade reliability and performance to domestic pools. Backed by a 2-year warranty and nationwide service network, it’s a professional solution at a sensible price point.

Dual Functionality = Space & Cost Savings

By combining dehumidification with LPHW air heating, the Monitair 75 eliminates the need for separate fan heaters, radiators, or supplementary heating equipment. One unit handles both moisture control and air warming – saving installation costs, space, and ongoing maintenance.

🚚 Ordering & Delivery Information

Delivery: Due to the size and weight (153 kg) of the Monitair 75, specialist delivery is required. Delivery costs and timescales will be confirmed at checkout based on your location. Please ensure adequate access for pallet delivery.

Lead Time: Please check current stock availability. Made-to-order units typically require 4-6 weeks for manufacture and delivery.

Returns Policy: Due to the specialized nature of this product, please ensure suitability before ordering. Contact our technical team with any questions about compatibility or sizing for your specific installation.

📞 Technical Support & Advice

Need expert advice? Contact us to discuss your indoor pool requirements with our experienced team.

⚙️ Technical Notes for Installers

Refrigerant: R407C (GWP: 1,774) – Qualified F-Gas certified engineers required for refrigerant work

Control System: Integrated humidistat with adjustable set point (20-80% RH). External air thermostat (supplied) controls LPHW heating function via motorized valve.

Defrost Operation: Automatic defrost cycle operates down to 5°C ambient. Unit continues to operate during defrost with minimal performance impact.

Airflow Pattern: Ensure unobstructed airflow across pool surface for optimal moisture pickup. Avoid short-circuiting supply and return air paths.

Commissioning: Allow 24-hour stabilization period after installation before final adjustments. Set humidistat to 55-60% RH for optimal balance between comfort and energy efficiency.

Electrical Protection: Motor-rated fuses essential due to compressor start-up current (LRA: 55A). Ensure adequate circuit protection and earth bonding.

🌟 Transform Your Indoor Pool Environment Today

The Monitair 75 DH75AX/L represents the perfect balance of performance, efficiency, and value for domestic and small commercial indoor pools. With powerful dehumidification, intelligent heat recovery, and integrated air heating, it’s the complete climate control solution that protects your pool building while creating a comfortable, inviting environment year-round.

Invest in comfort, efficiency, and long-term protection for your indoor pool facility.