Thermodynamic heat-recovery ventilation: ventilation + heating in 2026

Understand how thermodynamic heat-recovery ventilation works (and what it replaces)

Difference between single-flow, heat-recovery, and thermodynamic heat-recovery mechanical ventilation

With single-flow systems, stale air is extracted and fresh air enters through air inlets. With heat-recovery systems, a second network supplies fresh air after it passes through a heat exchanger. The thermodynamic version adds an integrated heat pump that tempers the supplied air. It can sometimes replace a small heating top-up, but not a boiler in a poorly insulated home.

Heat recovery, integrated heat pump: what happens inside the ducts

Inside the ducts, extracted air (kitchen, bathrooms) passes through filters, then through a heat exchanger that recovers part of the heat. The heat pump recovers further energy from the discharged air to heat, or cool depending on the model, the fresh air being supplied. Plan for condensate drainage and flow-rate adjustment, otherwise comfort switches off like a badly plugged-in lamp.

When thermodynamic mechanical ventilation makes sense (new build, renovation, small surfaces)

It makes sense in very high-performance new builds and in whole-home renovation with good airtightness, short networks and space for ducting. It suits small surface areas well, where a single unit ventilates and provides a light heating top-up. In partial renovation or a leaky home, it's better to insulate first, then choose suitable mechanical ventilation.

Assess feasibility on site before proposing mechanical ventilation

Building prerequisites: airtightness, insulation, flow rates and network balancing

Before any mechanical ventilation, check the consistency of the envelope. Proper insulation and controlled airtightness limit parasitic air inlets and secure the flow rates. Check extract points, air inlets and service rooms. Size the regulatory flow rates, then plan balancing to avoid over-ventilation, noise and discomfort.

Placement constraints: technical room, suspended ceilings, duct lengths, acoustics

Identify an accessible location for the unit, with an electrical supply and an outdoor outlet. Check the routes through lofts or suspended ceilings. Keep ducts short, with few bends, to limit pressure losses. Treat acoustics (hangers, anti-vibration mounts, insulated ducting) to preserve comfort.

Points of attention: condensation, condensate drainage, filters and maintenance access

With heat-recovery systems, anticipate condensation. Insulate ducts in cold zones and set up a slope toward a siphon for condensate drainage. Plan easy access to the filters, the bypass and the extract points. Realistic maintenance avoids performance loss and client complaints.

Quote it correctly: sizing, performance and consumption

Regulatory flow rates and sizing: avoiding under-ventilation and overconsumption

To quote for mechanical ventilation, start from the regulatory extraction flow rates per room. Sizing is then done using the network's pressure losses (lengths, bends, extract points, fan unit). Too small, and you keep humidity and CO2. Too large, and you pay for extra noise and watts.

Heat-recovery efficiency and the thermodynamic module's COP: how to read the technical sheets

On the heat-recovery side, look at the heat-recovery efficiency at nominal flow rate and the test conditions. Also check the fans' specific power, airtightness and filtration. For the thermodynamic module, rely on the COP at the test point and the seasonal SCOP, taking defrosting and backup heating into account.

Real-world consumption in 2026: usage scenarios and common adjustment mistakes

In continuous use, consumption mainly depends on the adjustment, the network and maintenance. Classic mistakes are leaving a high speed on permanently, clogged filters, balancing that was never done, or poorly insulated ducting. Fine-tuned adjustment and a flow-rate check after installation avoid quoting too low and then suffering the consequences later.

Financial aid and the 2026 framework: secure your applications and compliance

MaPrimeRénov' and CEE: eligibility conditions depending on the home and associated works

In 2026, first check the age of the home, its use (usually a primary residence) and the type of measure. MaPrimeRénov' and CEE are often combinable, but the CEE premium amount must be traceable (quote, offer, sworn statement). Think about "companion" works that condition performance, such as insulation and mechanical ventilation.

RGE certification and evidence to provide: quotes, sheets, photos, commissioning reports

To secure the aid, align your documents from the quote onward. RGE mention, product characteristics, CEE scheme sheet references, then a settled invoice. Add dated proof (before/after photos) and commissioning or adjustment reports (heat pump, boilers, heat-recovery mechanical ventilation).

Coordination with the energy audit and other trades (insulation, heating, windows)

When an audit is required, use it as a roadmap. The right order of trades avoids inconsistencies. Insulation and airtightness first, ventilation next, then heating sizing. Coordinate windows, air inlets and networks to avoid rework and inspection failures.

Installation and commissioning: deliver efficient, durable mechanical ventilation

Installation steps: networks, extract points, fan unit, airtightness, penetrations and duct insulation

For mechanical ventilation, performance mainly comes down to the installation. Aim for an airtight network that's accessible. Route short paths, limit bends, suspend the ducting without crushing it. Take care with penetrations (sleeves, sealing) and insulate ducting in unheated spaces to avoid condensation and losses. The fan unit is installed on anti-vibration mounts, with condensate drainage if needed.

Adjustments and checks: balancing, flow-rate measurements, noise, air quality

At commissioning, don't rely on how it feels. Measure the actual flow rates at each extract point, then adjust the settings to meet the sizing. Check the air inlets, undercut doors and the absence of network leaks. Check the noise (vibrations, whistling) and the consistency of scenarios (humidity control, kitchen boost, bypass).

Maintenance and after-sales: filters, exchanger, checking the thermodynamic module and client follow-up

To last, plan for simple maintenance. Schedule cleaning the extract points, replacing the filters, and dusting the exchanger on heat-recovery systems. On thermodynamic mechanical ventilation, check condensate flow, sensor condition and the unit's safety. Leave a dated maintenance sheet and offer an annual visit.