What is an FTX unit?
Supply and exhaust ventilation with heat recovery. Recovers 70–90% of the heat in outgoing air. Standard in modern Swedish houses. Saves 15–30% of heating costs.
Sources: BBR 6 · Energimyndigheten
Here are 8 common questions and answers in the category ventilation for the Swedish construction industry. Every answer is anchored in primary law (PBL, BBR, KTjL, AFS, ABS 18, AB 04) and authoritative guidance. The data is open and free to use with attribution.
Supply and exhaust ventilation with heat recovery. Recovers 70–90% of the heat in outgoing air. Standard in modern Swedish houses. Saves 15–30% of heating costs.
Sources: BBR 6 · Energimyndigheten
Every 3–6 months depending on type and location. A dirty filter means poorer air quality and higher energy use. Easy to change yourself. Filters cost 200–800 SEK per set.
Sources: Branschpraxis
FTX in a 150 m² house: 80,000–180,000 SEK including unit, ducts, diffusers. A healthy investment plus energy savings. ROT on the labour.
Sources: Branschindex 2026
Obligatorisk Ventilationskontroll. Required in multi-family, public and commercial premises every 3–6 years. Single-family houses are exempt. Carried out by a certified inspector. Defects can lead to enforcement orders.
Sources: SFS 2011:338
Yes, the labour cost for new ventilation or replacing existing systems in an existing house qualifies for ROT.
Sources: Inkomstskattelagen 67 kap.
0.35 l/s per m² floor area in dwellings as general flow. Kitchen: at least 10 l/s + 40 l/s during cooking. Bathroom: 15 l/s. Bedroom: 4 l/s/person.
Sources: BBR 6
Not as primary ventilation in new construction under BBR. Mechanical exhaust or FTX is required. In older homes passive ventilation can be sufficient but is energy-inefficient.
Sources: BBR 6
A sensor in bathroom/kitchen measures humidity and increases fan flow during showering/cooking. Efficient for energy and comfort. Standard on modern FTX units.
Sources: BBR 6