💨 English-speaking ventilation (MVHR) in Portugal · Free written quote · Lisbon · Algarve · Silver Coast
Ventilation & MVHR in Portugal — fresh air, no more damp, mould or stale rooms.
Your AC does not bring in fresh air — it cools and recirculates the same indoor air. Mechanical ventilation does the part the AC can’t: it renews the air 24/7 without opening windows. It clears the condensation in well-sealed new flats, the trapped damp after a renovation, the musty smell in a closed-up holiday home, and the poor air for anyone with allergies. This guide shows what it is, which system you need and what it costs. (Expats often call it MVHR — mechanical ventilation with heat recovery.)
💧 Indoor humidity held below 55%🛡️ 3-year equipment + 1-year labour warranty🌬️ Fresh, filtered air (HEPA option)💰 Single-flow from €890 + VAT
Request a quote — Ventilation
Free written quote · No-obligation survey · In English
🛡️ 3-year equipment warranty🧾 Official fatura with NIF✅ Site survey
What is ventilation (MVHR), and why your AC doesn’t bring in fresh air
Mechanical ventilation is a system that renews the indoor air continuously: it extracts damp, stale air from the bathrooms and kitchen and brings fresh, filtered air into the bedrooms and living room. It replaces “opening a window” — which loses energy in winter and isn’t enough in a well-sealed flat. Here’s the key point most people miss: air conditioning does not do this. AC cools (or heats) and recirculates the same indoor air, dust mites and all; it never brings in fresh outside air. Modern homes in Portugal are increasingly airtight (insulation plus sealed windows), which is great for the energy bill but traps moisture inside. Ventilation solves that without giving up the efficiency.
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Continuous air renewal
Runs 24/7 quietly (about 22 dB at night) — renews the air 0.5 to 0.8 times an hour, with no windows open, no heat lost in winter, and no street dust or noise getting in.
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Single-flow, double-flow or HEPA
Single-flow extracts the damp air (for damp and mould). Double-flow recovers 80–92% of the heat (for efficiency). Premium HEPA filters 99.95% of dust mites and pollen (for allergies). The right system depends on your situation.
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Fresh, filtered air — not recirculated
Unlike the AC (which recirculates the same air), ventilation brings in fresh outside air, filtered of particles, pollen and pollution. It keeps indoor humidity at 40–55%, the range where mould and dust mites don’t take hold.
Which situation is yours? — a quick guide by case
Three situations we see most often in Portugal, each pointing to a different system. No names, no addresses — just the question “which system makes sense for me?”. For your exact case in your region, see the local page further down.
The damp city apartment
Well-sealed new buildMisted windowsMould by 2nd winter
We bought a well-insulated new flat, and by the second winter mould appeared in the bedroom and the windows mist up every morning. No one warned us it would need extra ventilation.
Single-flow from €890 + VAT. This is the classic post-2015 flat: the airtight envelope traps the moisture that people, plants and cooking produce, and the AC just recirculates it.
It extracts the damp air continuously, holds humidity at 40–55%, and the mould doesn’t come back. Installed in a day, no building work. €890 turn-key.
Single-flow from €890 + VAT · 1-day install · humidity held at 40–55%, mould cleared for good.
We renovated the house — new windows, insulation — and now the damp is trapped inside the walls. The stains come back after every repaint and there’s a persistent musty smell.
Double-flow (MVHR) from €2,490 + VAT. The airtight renovation closed off the natural ventilation the old house used to have — without putting it back, the moisture has nowhere to go.
Double-flow renews the air and recovers 80–92% of the heat, so you don’t waste energy. Discreet internal ducting, ideal for character or protected buildings. €2,490 with design.
Double-flow from €2,490 + VAT · 80–92% heat recovery · discreet ducting, paperwork for the council where needed.
Shut between stays“Musty” reviewsOwner often abroad
We let our place as a short-let and we’re abroad much of the year. Guests leave reviews mentioning a “musty smell” when it’s been shut for a few days, and the rating has slipped.
Single-flow from €890 + VAT, on automatic 24/7 — it works with no one there. It renews the air in the closed flat between stays and clears the musty smell before the guest arrives.
For several apartments there’s a volume discount. The payback is quick: protecting the rating is worth more than the investment in the first year. We coordinate remotely with your key-holder.
Single-flow from €890/unit · automatic 24/7 · protects rating and pricing power, runs by itself while you’re away.
General cases for guidance. For your exact situation — with your region and home — see the local page for your area further down. Allergy or asthma in the home? That points to the HEPA tier below.
What’s the symptom in your home? See which system solves it
Ventilation isn’t a one-size-fits-all fix — the right system depends on the symptom. Here’s the direct translation between what you’re seeing and the type that makes sense.
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Condensation on the glass, windows misted up in the morning
→ Single-flow (from €890 + VAT). The classic sign of a well-sealed flat trapping moisture. Continuous extraction fixes it for good.
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Mould in the corners, stains that come back after a repaint
→ Single-flow or double-flow (€890–2,490 + VAT). Damp trapped by an airtight renovation. Double-flow adds heat recovery.
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Musty smell, or “musty” in the short-let reviews
→ Automatic single-flow (from €890 + VAT). Runs 24/7 with no one there — renews the air between stays and protects the rating.
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A child with asthma or allergies, and a home that stays closed up
→ Premium HEPA (from €3,990 + VAT). H13 filters capture 99.95% of dust mites, pollen and fine particles. Continuous supply of fresh, filtered air.
Ventilation systems in Portugal 2026 — single-flow, double-flow or HEPA?
Three tiers of mechanical ventilation. “From” prices + VAT, installation included, valid across all regions we cover. Exact quote after a site survey with sizing — official fatura with your NIF.
Most popular
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Single-flow — damp & stale air
from €890 + VAT
from, equipment + turn-key installation (up to 80 m²)
Equipment: humidity-controlled centrifugal fan · A energy class
For well-sealed new flats, short-lets and homes with mould from excess moisture — continuous extraction from the wet rooms
0.5–0.6 air changes/hour · automatic 24/7 mode (ideal for a short-let shut between stays) · about 22 dB at night
8–12 W continuous (€40–60/year) · G4 filters (changed every 6 months) · marine-grade version for coastal homes
Installed in a single day, no building work · 3-year equipment + 1-year labour warranty
Equipment: double-flow heat-recovery unit · 80–92% heat recovery in the counter-flow exchanger (EN 13141-7)
For airtight renovations, efficient homes and character or protected buildings — renews the air and recovers the heat the outgoing air would carry away
Cuts the heating bill 15–25% · fresh air arrives pre-warmed in the bedrooms · G4 filters + optional activated carbon
Discreet internal trunking · technical write-up and project sheet for the council where needed
When is ventilation actually needed? — the honest answer
It’s the most common question, and there’s a lot of bad information out there. Here’s the practical picture: ventilation is rarely a strict legal requirement, but in modern homes it’s usually the only thing that works.
The short answer
Not strictly mandatory — but a minimum applies
A ventilation system isn’t specifically required by law. What the Portuguese building rules ask for is a minimum amount of fresh-air change in new homes and deep renovations — enough to keep the indoor air healthy and dry.
Portuguese building ventilation standard
Three ways to meet it
You have a choice of method
That minimum can be met in any of these ways:
Natural ventilation — vents and windows
Mechanical ventilation (single- or double-flow)
A hybrid (natural intake + mechanical extraction)
The rules don’t force one specific method — it’s a design choice for your home.
Natural · mechanical · hybrid
In practice
Why ventilation has become the norm
Modern homes built to today’s energy standards are airtight by design. In those homes, natural ventilation rarely brings in enough fresh air on its own — so mechanical ventilation has become the practical default.
Large renovations have to meet the same standard. So even where it isn’t strictly mandatory, ventilation is usually what actually keeps the air fresh and the mould away.
Airtight build · renovation · the practical fix
What to check before you hire a ventilation installer
Three quality signals to ask of any ventilation installer in Portugal — a certified team, work done to standard, and real commercial protection in writing.
Certified team
F-Gas Cat. I, work done to standard
Our team includes technicians certified to F-Gas Category I (the highest level for the refrigerant circuit, relevant when the ventilation work meets the AC or heat-pump system), and we work to the Portuguese building ventilation standard.
Correct sizing for your home (W/m²)
Work done to the building ventilation standard
Project write-up for the council where needed
F-Gas Cat. I · English-speaking
Commercial warranty
3 years on equipment + 1 year on labour
A VentoFix warranty of 3 years on the equipment plus 1 year on labour — above the usual 2-year market standard. Includes direct after-sales support, with no middlemen.
Signed technical report in PDF
Before/after photos of the installation
Maintenance and filter-change plan
2026 pricing · + VAT · official fatura with NIF
An informed decision
Site survey + written quote
A site survey with a humidity reading and proper sizing, and a written quote before you commit to anything. We tell you what makes sense for your case — and what doesn’t.
Indoor humidity measured on site
Honest tier recommendation (no upsell)
Fixed price, no surprises at the end
⚠An installer who promises to cure rising damp with ventilation → a warning sign. Ventilation treats the air, not the wall.
2026 pricing · + VAT · no obligation
Ventilation & MVHR in Portugal — choose your region
We cover three regions with local English-speaking technicians. Each has its own reality — climate, housing stock, density of holiday lets. See your area’s page for local scenarios and the specifics that matter where you are.
Mechanical ventilation (the expats’ term is MVHR, often with heat recovery) is a system that renews the indoor air continuously — it extracts damp, stale air from the bathrooms and kitchen (the wet rooms) and brings fresh, filtered air into the bedrooms and living room (the dry rooms). It runs 24/7 quietly (about 22 dB at night), with no need to open windows and no heat lost in winter. It keeps indoor humidity at 40–55%, the range where mould and dust mites don’t take hold.
No, and this is the most common misunderstanding. Air conditioning cools (or heats) the same indoor air and recirculates it — dust mites, CO₂ and stale air included. It does not bring in fresh outside air. That’s why a flat with AC can still smell musty and feel stuffy. Ventilation is the part the AC doesn’t do: it removes stale air and brings in fresh, filtered air from outside, continuously.
Single-flow: one fan extracts air from the wet rooms; fresh air comes in naturally through vents. Cheaper (from €890 + VAT), ideal for clearing damp, mould and the stale-air smell in flats and short-lets. Double-flow with heat recovery (MVHR): two fans plus a heat exchanger recover 80–92% of the energy from the outgoing air, so the incoming fresh air arrives already tempered, keeping the warmth in winter and the cool in summer. It cuts heating cost by 15–25%. Best for renovated airtight homes, larger houses, and (with HEPA filters) for allergies.
Three tiers, + VAT, installation included: single-flow from €890 (up to 80 m²) for damp, mould and stale-air smells; double-flow MVHR from €2,490 with 80–92% heat recovery for renovations and efficiency; premium HEPA from €3,990 with H13 filters for allergies and asthma. Prices are national; a marine-grade version for coastal homes near the sea may add a little. The site survey includes sizing and a written quote, with an official fatura and your NIF.
It’s the paradox of modern building: the better the insulation, the less air moves naturally. Well-sealed flats built after 2015 trap the moisture that people, plants and cooking produce; it condenses on the windows and cold corners, and mould appears by the second winter. A single-flow unit from €890 + VAT extracts the damp air continuously, holds humidity at 40–55%, and the mould doesn’t come back. Installed in a day, with no building work.
A portable dehumidifier removes some moisture from the existing air but does not renew it — CO₂ builds up, dust mites multiply, allergens stay. It treats one symptom. Ventilation renews the air continuously — it removes moisture, CO₂, dust mites and particles and brings in fresh, filtered air. It’s the lasting fix. Running cost: a dehumidifier is €120–280/year (electricity plus upkeep); a single-flow ventilation unit is €40–60/year, continuous.
Yes — it’s one of the quickest-payback investments for a short-let. A flat shut between guests builds up stale air and a musty smell that guests mention in reviews (“musty smell”, “stuffy”), and that drags down your rating and your pricing power. A single-flow unit from €890 + VAT running 24/7 renews the air with no one there, clearing the problem before the next guest arrives. For owners abroad it runs by itself all winter, and there’s a volume discount for several apartments.
For a child with asthma or allergies, a premium double-flow system with HEPA H13 filters (from €3,990 + VAT) makes a real difference. The H13 filters capture 99.95% of dust mites, pollen and fine particles — something a dehumidifier or AC simply don’t do, because the AC recirculates the same air. It holds humidity at 40–55% (where dust mites can’t breed) and brings in fresh, filtered air, especially in the bedroom. A phased option is available: the child’s room first (from €1,200), the rest of the home later.
No. For single-flow, the ducting runs in discreet trunking along the inside walls — no structural walls drilled, no tiles broken, no floors lifted. The only visible trace is the small vent grilles (about 5×15 cm), discreet and paintable to match the wall. Double-flow needs a bit more planning (a heat-recovery unit and insulated ducting) but keeps the same minimal-intervention principle. Installation takes one day (single-flow) or 2–3 days (double-flow).
No — and we’d rather be straight with you. Rising damp (moisture climbing the walls from the ground, with a dark tide-mark, salts and crumbling plaster, common in old stone or rammed-earth houses) is a structural problem that needs a damp barrier or wall treatment. Ventilation does not cure it. What ventilation fixes is the indoor air: the musty smell, surface mould and heavy, stale air, especially after an airtight renovation. On the survey we explain which is which and what each solution actually does.
Maintenance is simple: changing the filters (G4 about every 6 months; HEPA H13 every 12–18 months) and an occasional clean of the grilles and ducts. Single-flow needs almost nothing beyond filters; double-flow benefits from a yearly check of the heat exchanger and fans. We provide a maintenance plan with every installation and can carry out the service. We cover three regions with local English-speaking technicians: Greater Lisbon, the Algarve and the Silver Coast — each has its own page with local scenarios. Written quote in 48–72h after the survey.
Clean, dry air without opening a window. Ventilation installed in 1–3 days, anywhere in Portugal.
Site survey · written quote · honest tier recommendation · three systems from €890 + VAT.