How to Choose the Right ERV for Your Building

Choosing the right energy recovery ventilator (ERV) can feel overwhelming. With dozens of products on the market — each with different airflow ratings, heat recovery efficiencies, noise levels, and connectivity options — how do you know which one is right for your project? This guide provides a clear, step-by-step decision framework.

Step 1: Identify Your Building Type

The single most important factor in choosing an ERV is the type of building it will be installed in. Different buildings have different ventilation requirements, regulatory standards, and practical constraints.

Residential (Houses and Apartments)

Residential ventilation needs to be quiet, efficient, and unobtrusive. Building regulations typically require a minimum ventilation rate of 0.5 air changes per hour (ACH), with extract rates of 8 l/s in kitchens and 6 l/s in bathrooms. For bedrooms and living rooms, background ventilation of 15–30 m3/h per room is standard.

Recommended products:

• AirPro V2.0 — The flagship choice for bedrooms, living rooms, and home offices. 97% heat recovery, 12 dB noise, WiFi control. Fits walls from 280mm thick.
• Air Nano — For thin walls (down to 220mm) or small rooms. Same 97% heat recovery in a compact 110mm format.
• Air Duo — Double-room unit for larger spaces or open-plan living. Handles up to 120 m3/h with simultaneous supply and extract.
• Air Mini — Budget-friendly option for rooms requiring basic ventilation without smart features.

Schools and Educational Buildings

Schools present unique challenges: high occupancy density (25–30 students per classroom), strict CO2 limits (typically below 1,000 ppm), noise sensitivity during lessons, and the need for robust, tamper-resistant equipment. European standard EN 16798-1 recommends 7 l/s per person for Category II indoor air quality.

Recommended products:

• AirSchool — Floor-standing unit designed specifically for classrooms. Built-in CO2 sensor, traffic-light display for teachers, robust steel enclosure, and up to 210 m3/h airflow. Two units per standard classroom provide 420 m3/h — enough for 30 students.
• AirSchool Top — Ceiling-mounted variant for rooms where floor space is at a premium. Same performance as AirSchool in a horizontal format.

Commercial and Office Buildings

Commercial buildings require higher airflow rates, often need to integrate with building management systems (BMS), and may have specific acoustic requirements for open-plan offices, meeting rooms, and server rooms.

Recommended products:

• AirCeil — Ceiling-mounted ERV for offices, retail, and hospitality. Handles up to 180 m3/h with Modbus connectivity for BMS integration.
• Air Comfort — High-capacity wall-mounted unit for larger commercial spaces. Up to 300 m3/h with integrated heating element for cold climates.
• AirRes — Multi-dwelling residential unit for apartment corridors and common areas.

Step 2: Calculate Required Airflow

Once you know the building type, calculate the required airflow for each room. The basic formula is:

For residential rooms, the calculation is simpler: most bedrooms need 15–30 m3/h, living rooms need 30–60 m3/h, and open-plan spaces may need 60–120 m3/h depending on size and occupancy.

Always size for peak occupancy, not average occupancy. An under-ventilated room will have elevated CO2 levels, which reduces cognitive performance, increases fatigue, and can cause headaches.

Step 3: Evaluate Key Specifications

With your building type and airflow requirements established, compare products across these critical specifications:

Heat Recovery Efficiency

This is the percentage of heat that the unit recovers from exhaust air and transfers to incoming fresh air. Higher is better — it directly reduces heating costs. Din Ventilation units achieve up to 97% using patented ceramic regenerative heat exchangers. Most competitors achieve 75–85% with counter-flow plate exchangers.

A 10% difference in heat recovery efficiency can save EUR 100–200 per unit per year in heating costs, depending on climate and energy prices. Over a 15-year product lifetime, that adds up to EUR 1,500–3,000 per unit.

Noise Level

Noise is critical in bedrooms, classrooms, and offices. The AirPro V2.0 operates at just 12 dB(A) on its lowest setting — that is quieter than a whisper (20 dB) and effectively inaudible in any furnished room. For comparison, many competing units operate at 25–35 dB(A), which is clearly audible and can disturb sleep or concentration.

Always check the noise rating at the airflow speed you will actually use, not just the minimum. Some manufacturers quote noise at the lowest speed, which may not provide sufficient airflow.

Connectivity and Smart Features

Modern ERV units offer a range of smart features:

• WiFi / App Control: The AirLinq app allows remote monitoring and control of all Din Ventilation units. Set schedules, adjust fan speeds, and view indoor air quality data from your phone.
• CO2 Sensors: Built into AirSchool and available as add-ons for other models. Enable demand-controlled ventilation that ramps up when CO2 rises and reduces when rooms are unoccupied — saving energy while maintaining air quality.
• Humidity Sensors: Built into all Din Ventilation units. Automatically increase ventilation when humidity rises (e.g., during cooking or showering) to prevent condensation and mould.
• BMS Integration: AirCeil and Air Comfort support Modbus RTU for integration with commercial building management systems.

Step 4: Consider Practical Constraints

Before finalising your choice, check these practical factors:

• Wall thickness: The AirPro V2.0 requires a minimum wall thickness of 280mm. For thinner walls, choose the Air Nano (220mm minimum).
• External wall access: Every decentralised unit needs an external wall. Internal rooms without external walls cannot use decentralised ventilation and may need ductwork connections to nearby external walls.
• Power supply: All Din Ventilation units run on standard 230V mains power. Ensure there is a power socket or spur available near each unit location.
• Planning restrictions: Listed buildings or properties in conservation areas may have restrictions on external wall penetrations. Check with your local planning authority before drilling.

Step 5: Choose Your Product

Use this quick decision matrix:

Conclusion

Choosing the right ERV comes down to four factors: building type, required airflow, key specifications (heat recovery, noise, connectivity), and practical constraints (wall thickness, external access). Start with your building type to narrow the field, calculate your airflow needs, and then compare the shortlisted products on the specifications that matter most for your application. If you need help, our technical team can provide a detailed ventilation design for your project — just request a quote.