The Vectaire Cool Breeze is supplied as a complete system with the Vectaire Maxi MVHR unit — combining whole-house mechanical ventilation with heat recovery and active overheating mitigation in a single integrated solution for residential properties up to 250 m². The Maxi provides continuous fresh filtered air with up to 92% heat recovery efficiency, while the Cool Breeze actively cools the incoming supply air by up to 20°C during warmer months — delivering up to 4.1 kW of total cooling capacity without any external condenser unit. The system uses R290, a natural refrigerant with a Global Warming Potential of just 3 — over 225 times more environmentally friendly than R32. Together, the Cool Breeze and Maxi meet the overheating assessment standards of CIBSE TM59 and Approved Document O of the UK Building Regulations, providing developers, architects, and self-builders with a fully compliant, no-external-condenser solution for year-round indoor climate control.
4.1 kW
Max Cooling Capacity
COP 4.3
Coefficient of Performance
GWP 3
R290 Natural Refrigerant
Installer Note: The Cool Breeze uses R290 (propane) — a flammable refrigerant classified A3. Installation of the refrigerant circuit must be carried out by a suitably qualified F-Gas or equivalent refrigerant engineer in accordance with relevant safety regulations. The system is sealed for life and must not be modified or recharged. Ensure adequate ventilation in the plant location. The Maxi MVHR must be installed and commissioned in accordance with Building Regulations Part F by a competent person. Allow 200 mm clearance each side of the Maxi for motor access.
Supplied Together — Maxi MVHR + Cool Breeze: This listing covers the complete Cool Breeze system as supplied with the Vectaire Maxi MVHR. The Cool Breeze cooling module is designed and engineered exclusively for the Maxi and is not compatible with any other MVHR unit. For larger properties up to 400 m², the Cool Breeze Plus with Maxi Plus BY is the correct system. Wall bracket or floor stand required for the cooling module — available separately. Confirm handing and installation configuration before ordering.
Approved Document O & CIBSE TM59 Compliant. The Cool Breeze + Maxi combination meets the overheating assessment standards used in CIBSE TM59 and Approved Document O of the Building Regulations — providing a fully documented, compliant route to overheating mitigation for new residential buildings. The Maxi is SAP PCDB Listed, CE marked, and manufactured in the UK to ISO 9001:2015 and ISO 14001:2015. The Cool Breeze is a Vectaire Registered Design.
Cool Breeze — Cooling Module Features
R290 Natural Refrigerant — GWP 3
The Cool Breeze uses R290 (propane), a natural refrigerant with a Global Warming Potential of just 3 — compared to 675 for R32 and 2088 for R410A. R290 is over 225 times more environmentally friendly than R32, making this one of the most climate-responsible active cooling solutions available for UK residential use today.
4.1 kW Cooling — No External Condenser
The self-contained, sealed-for-life system delivers up to 4.1 kW of total cooling at 700 W of electrical power. The integral condenser rejects heat through the Maxi's exhaust airstream — so no external condenser unit is required. This eliminates the planning, aesthetic, and noise issues associated with conventional split-system air conditioning, making it ideal for new builds, listed properties, and conservation areas.
Cools Supply Air by Up to 20°C
The Cool Breeze removes heat from the Maxi's fresh supply airstream before it is distributed throughout the home. At 30°C external / 23°C internal and 90 l/s airflow, the supply air temperature reaches 11.7°C with a total cooling power of 2.19 kW at 50% relative humidity. At an external temperature of 34°C the system delivers up to 2.45 kW at 110 l/s.
COP up to 4.3 — EER up to 3.2
With a Coefficient of Performance of up to 4.3 and an Energy Efficiency Ratio of up to 3.2, the Cool Breeze delivers significantly more cooling energy than it consumes electrically — outperforming many conventional domestic air conditioning units. This results in lower running costs and a smaller carbon footprint during warmer periods.
Automatic Integral Sensor Control
The Cool Breeze automatically senses both room temperature and incoming fresh air temperature via an integral sensor, activating cooling only when conditions require it. This eliminates false triggering from a poorly sited external thermostat. An optional manual override allows occupants to control cooling independently. Universal handing is achieved via intelligent software — no mechanical adjustment required on site.
Very Quiet — Front Service Access
The very quiet integral condenser operates within the Maxi's exhaust duct, generating no external fan noise. At 100% speed (140 l/s), breakout sound pressure is 38.6 dBA at 3 m; at 60% (80 l/s) this falls to 34.5 dBA. All servicing is via front access panels — no additional side or rear clearance is needed for the cooling module beyond the Maxi's standard 200 mm motor clearance.
Wall or Floor Installation
The Cool Breeze + Maxi combination can be installed in wall-mounted or floor-standing configurations using the appropriate wall bracket or floor stand (available separately). The combined unit is 818 mm wide and up to 1482 mm tall in the wall bracket arrangement, or 1319 mm on a floor stand — suited to plant rooms, utility spaces, or loft installations with adequate head height.
Fresh Air — Not Recirculated Air
Unlike a conventional split-system air conditioner, the Cool Breeze cools fresh outdoor air as it enters the home via the Maxi MVHR — it never recirculates stale indoor air. Occupants receive continuous cooled, filtered fresh air distributed throughout the property, maintaining the full indoor air quality benefits of MVHR alongside active cooling. Particularly suited to allergy sufferers, Passivhaus-adjacent designs, and high-specification new builds.
Vectaire Maxi MVHR — Supplied with the Cool Breeze
Up to 92% Counter-Flow Heat Recovery
The Maxi's counter-flow heat exchanger achieves up to 92% thermal efficiency, recovering warmth from stale exhaust air and transferring it to incoming fresh supply air without the two airstreams mixing. Under SAP 10 at kitchen plus one wet room, it delivers 92% efficiency at 0.45 W/l/s SFP — meeting the most demanding Building Regulations energy targets.
Fully Automatic Summer Bypass
The Maxi includes a fully automatic summer bypass that monitors internal and external temperatures, routing incoming fresh air around the heat exchanger when outdoor conditions allow passive cooling. When active cooling is needed, the Cool Breeze takes over — the two systems work seamlessly together to maintain comfort across all seasons without manual intervention.
High-Quality EC Brushless Motors
The Maxi uses energy-efficient EC brushless motors with forward curved impellers and direct drive, covering five airflow steps from 23 l/s to 177 l/s. At 100% the unit draws just 176 W; at 20% speed only 4 W. Specific fan power is down to 0.40 W/l/s — one of the lowest SFP values available for an MVHR unit of this capacity.
Integral Frost-Stat & Smart Controls
The Maxi includes an integral frost-stat that proportionally reduces intake fan speed as outside temperatures fall between +3°C and −8°C, protecting the heat exchanger from icing. Factory-set options include 0-10V connections for BMS, CO₂ detection, and home automation; integral humidistat; holiday mode; and run-time counters downloadable via QR code. Optional integral or remote LCD commissioning unit available.
Technical Specifications — Cool Breeze Cooling Module
| Max Total Cooling Capacity |
4.1 kW |
| Power Consumption |
700 W |
| Full Load Current (FLC) |
4.8 A |
| COP (max) |
4.3 |
| EER (max) |
3.2 |
| Refrigerant |
R290 (propane) — natural refrigerant, GWP 3 |
| Max Supply Air Temperature Reduction |
Up to 20°C |
| Breakout Sound Pressure @ 3m |
38.6 dBA @ 100% (140 l/s) · 34.5 dBA @ 60% (80 l/s) |
| Cooling Unit Weight |
58 kg |
| Installation Options |
Wall mounted or floor standing (bracket/stand sold separately) |
| Handing |
Universal via intelligent software |
| Servicing Access |
Front access |
Technical Specifications — Vectaire Maxi MVHR (Supplied With)
| Max Airflow Capacity |
177 l/s (637 m³/hr) |
| Airflow at 50Pa |
163 l/s |
| Heat Exchange Efficiency (max) |
92% (SAP 10: Kitchen + 1 wet room) |
| Specific Fan Power (SFP) |
Down to 0.40 W/l/s |
| Total Power — 100% / 20% |
176 W / 4 W |
| Operating Current |
1.41 A |
| Airflow Speeds (l/s) |
177 / 138 / 99 / 60 / 23 (100%–20%) |
| Breakout Sound Pressure @ 3m |
38.1 dBA @ 100% · 20.2 dBA @ 20% |
| Frost-Stat Activation Range |
+3°C to −8°C (outside temperature) |
| Filter Grade |
G3 disposable, easily accessible |
| Maxi Weight |
37 kg (Maxi) · 42 kg (Maxi-AT) |
| Duct Connection Diameter |
Ø149 mm |
| Combined Height — Wall Bracket |
1482 mm |
| Combined Height — Floor Stand |
1319 mm |
| Combined Width |
818 mm (front) · 823 mm (rear) |
| Warranty |
5 years (1 year parts & labour, 4 years parts only) |
| Certifications |
SAP PCDB Listed · CE Marked · ISO 9001:2015 · ISO 14001:2015 · EU RoHS |
| System Compliance |
CIBSE TM59 · Approved Document O · Building Regulations Part F & Part L |
| Sound Testing Standard |
BS EN ISO 3743-1:2010 (independently tested) |
| Manufacturer |
Vectaire Ltd, High Wycombe, UK |
Frequently Asked Questions
What does this listing include — is the Maxi MVHR supplied with the Cool Breeze?
Yes. The Cool Breeze is supplied as a complete system with the Vectaire Maxi MVHR. The two units are engineered to work together: the Maxi handles year-round fresh air ventilation and heat recovery, and the Cool Breeze actively cools the incoming supply air during warmer months. The Cool Breeze is not available for use with any other MVHR system.
How is this different from a conventional air conditioner?
A conventional split-system air conditioner recirculates and cools existing indoor air. The Cool Breeze cools fresh outdoor air as it enters the home through the Maxi MVHR, so occupants receive continuously cooled, filtered fresh air — not recycled stale air. The system also requires no external condenser unit, avoiding the planning, aesthetic, and external noise issues of conventional AC.
Does this system satisfy Approved Document O?
Yes. The Cool Breeze + Maxi system meets the standards used in CIBSE TM59 overheating assessments and Approved Document O of the UK Building Regulations. It provides architects, developers, and self-builders with a fully documented, compliant overheating mitigation route for new residential buildings subject to Part O requirements.
Why does the Cool Breeze use R290 and what does GWP 3 mean?
R290 (propane) is a natural refrigerant with a Global Warming Potential of just 3, compared to 675 for R32 and 2088 for R410A — making it over 225 times more environmentally friendly than R32. Despite being flammable (classified A3), the sealed-for-life charge in the Cool Breeze is small and safe when installed correctly by a qualified engineer. The use of R290 also contributes to the unit's high COP of up to 4.3, reducing running costs and energy consumption.
What is the difference between this system and the Cool Breeze Plus with Maxi Plus BY?
The Cool Breeze + Maxi is the system for homes up to 250 m², with a Maxi peak airflow of 177 l/s and up to 4.1 kW cooling at COP 4.3. The Cool Breeze Plus + Maxi Plus BY is the system for larger homes up to 400 m², with a Maxi Plus BY peak airflow of 238 l/s and up to 4.3 kW cooling at a significantly higher COP of 6.5 and EER of 4.6. The two systems are not interchangeable — each cooling module is designed exclusively for its paired MVHR unit.
What support is available for specifying and installing this system?
Casavent provides full end-to-end design support for Cool Breeze + Maxi projects, including overheating assessment guidance, full system specification, CAD drawings, airflow and pressure calculations, and component breakdowns. As members of the Young's Extract Supplies Group, Casavent works with self-builders, contractors, architects, and developers across the UK to deliver compliant ventilation and cooling solutions from specification through to commissioning.
