Flexit Nordic S3 is a mid-range central air handling unit from the Norwegian Nordic series — engineered for larger family homes and residential buildings. The rotary heat exchanger delivers a thermal efficiency of up to 85 %, airflow up to 361 m³/h and a built-in humidity sensor with full control via the Flexit GO app. Available in right-hand (RER) and left-hand (REL) configurations. The ideal solution for demanding projects requiring higher ventilation capacity with maximum energy savings.
Key Benefits
Smart Control with Flexit GO
Control the unit from anywhere via the mobile app or web interface. Modbus support for smart home integration. Optional CI70 control panel for local operation.
Flexible Installation
Mount the unit on a wall, stand it upright or lay it horizontally on the floor. Available in left-hand and right-hand configurations, with or without electric pre-heater.
Kitchen Hood Connection
Simple connection to a kitchen hood via the bypass duct (Ø125 mm). Supports effective extraction of cooking fumes directly through the central ventilation system.
Healthier Air Throughout the Home
Dual F7 filtration captures dust particles, pollen and allergens. Heat recovery removes excess humidity and CO₂, reducing the risk of mould growth and allergic reactions.
Why a rotary heat exchanger?
Unlike plate heat exchangers, a rotary heat exchanger provides higher heat recovery efficiency in cold climates. Seasonal heat recovery (summer and winter) is a standard feature of the Nordic range — the unit rejects heat from the supply air in summer and recovers it in winter.
For sub-zero operation, a defrost function is available in the Flexit GO app, preventing ice build-up and ensuring reliable year-round performance.
Annual Energy Savings
Flexit Nordic S3 significantly reduces heating costs thanks to the high-efficiency rotary exchanger. Estimated annual savings by climate zone:
(e.g. Scandinavia, mountain regions)
(e.g. Central Europe)
(e.g. Mediterranean region)
Technical Specifications
| Parameter | Value |
|---|---|
| Temperature efficiency | up to 85 % |
| Max. airflow | 361 m³/h (RER) / 350 m³/h (REL) at 100 Pa |
| Heat exchanger type | Rotary (enthalpy) |
| Filter class | 2× ePM1 55 % (F7) |
| Filter dimensions | 166×272×48 mm |
| Sound power level | 42 dB(A) |
| Rated voltage | 230 V / 50 Hz |
| Rated power (total) | 679 W |
| Fan power | 2×83 W |
| Electric heater power | 500 W |
| Rated current | 3.4 A |
| Fan type | B-wheel, 0–10 V control |
| Duct connection | Ø125 mm |
| Kitchen hood connection | Ø125 mm |
| Dimensions (W×H×D) | 599×777×537 mm |
| Weight | 56 kg |
| Colour | White, RAL 9016 |
| Control | Flexit GO (LAN, cloud, app) |
| Compatibility | Modbus, Flexit GO, CI70 panel (optional) |
| Configuration | Right-hand (RER) / Left-hand (REL) |
Flexit Nordic S3 vs Nordic S2 — which model to choose?
Nordic S3 offers higher maximum airflow (361 m³/h vs 349 m³/h), making it better suited for larger family homes and properties with higher ventilation demands. Both models share the same rotary exchanger with 85 % efficiency, identical F7 filters and Flexit GO control.
For smaller apartments and homes with lower airflow requirements, choose Flexit Nordic S2. For even larger spaces, consider Nordic S4 with airflow up to 475 m³/h.
Performance. Quiet operation. Healthy air for the whole home.
Flexit Nordic S3 is a reliable central air handling unit for demanding projects requiring higher ventilation capacity, maximum energy savings and intuitive smart control — available in right-hand (RER) and left-hand (REL) configurations.
| Model (Exterior side) | REL (Left) or RER (Right) |
| Brand | Flexit |
| Max. air flow m³/h | 350 m³/h |