Heat recovery ventilation

What we do

We design and install mechanical ventilation with heat recovery (MVHR) in houses. A separate team has handled this work since 2015 and has completed more than 1,100 systems. The unit extracts stale air from the kitchen, bathrooms and walk-in wardrobes and supplies fresh air to the living rooms and bedrooms, warmed in the heat exchanger by the outgoing air. The air is filtered, there are no draughts and no condensation on the windows.

Who it is for

• New houses. An airtight, well-insulated house without mechanical ventilation quickly ends up too humid, with too much CO₂ in the bedrooms. This is where heat recovery ventilation makes the most sense and costs the least.
• Houses after a thermal retrofit. New windows and insulation seal the building, and natural ventilation often stops working. Installation is harder, but usually possible.
• Houses with a heat pump. Heat recovery reduces ventilation heat losses, so the heat pump can be smaller and cheaper to run.

To be honest, in an uninsulated, leaky house heat recovery ventilation will deliver less than you expect. In that case we will recommend other work first.

How the job runs

1. Site visit or design review. We work out where the unit will go, how the ducts will run and where the air intake and exhaust can be placed.
2. Design. We calculate the airflow for every room and choose the unit, duct sizes and diffuser positions.
3. First fix. At shell stage we lay the ducts, plenum boxes and manifolds. We cap the ducts so building dust stays out.
4. Second fix. After the interior is finished we install the unit, silencers, diffusers and controller, and connect the condensate drain.
5. Balancing and handover. We measure the airflow at every diffuser and set the system to match the design. You get a report with the measurements and we show you how to change the filters.

What we watch out for

• We place the air intake away from the chimney, the exhaust terminal and the bins.
• We do not connect the kitchen hood to the ventilation system. Grease contaminates the heat exchanger, so the hood either recirculates or has its own outlet.
• We insulate ducts in unheated spaces so condensation does not form on them.
• The condensate drain from the unit runs through a trap to the sewer, with access for cleaning.

What is included

Design, unit with a counterflow heat exchanger, ducts and fittings, plenum boxes, diffusers, air intake and exhaust terminals, silencers, duct insulation in unheated spaces, controller, condensate drain, two-stage installation and balancing with a report.

What affects the price

• the size of the house and number of rooms,
• unit capacity and features, such as an enthalpy exchanger, summer bypass, humidity or CO₂ sensors,
• how the ducts run: in the floor, in the ceiling or through an unheated loft,
• in occupied houses: boxing-in and making good after installation.

Subsidies

Heat recovery ventilation can be funded under Czyste Powietrze if the unit is on the ZUM list, and it is an eligible expense for the thermal retrofit tax relief (ulga termomodernizacyjna). We help you check the conditions and always confirm the current rules on the official programme websites.