MVHR, AHU
& extract.
Mechanical ventilation, heat recovery and extract — sized properly, ducted properly, balanced properly. Compliant first time.
Included scope.
- MVHR for homes & flats
- Commercial AHU plant
- Kitchen extract canopies
- Bathroom & wet-room extract
- Smoke ventilation (SHEV)
- Duct cleaning & balancing
- Part F compliance
- System commissioning
Design, install, commission.
Ventilation that performs needs proper design before the kit is ordered. Five steps from survey to a commissioned system.
- Site survey (30-45 min, free) — measure rooms, identify wet rooms and habitable rooms, check ceiling void depth for duct runs, locate suitable plant position.
- Design + heat-loss calc — industry-standard duct sizing, air-flow targets per room, heat-recovery efficiency modelling for MVHR.
- Written quote (48 hours) — specific brand and model, duct route, valve positions, commissioning targets.
- Install (1-3 days domestic, longer commercial) — MVHR retrofit 2-3 days, dMEV single fan 2-4 hours, PIV 2-4 hours, commercial AHU 1-2 weeks.
- Commissioning & balance — air-flow balanced at each terminal with anemometer, documented in a commissioning report, controls programmed.
Ventilation systems we install.
We work with the major UK ventilation brands and design each system for the building it’s going into — airtight new build, leaky retrofit, or commercial.
- MVHR (Mechanical Ventilation with Heat Recovery): Vent-Axia Sentinel Kinetic, Zehnder ComfoAir Q450, Brink Renovent, Aereco DXR. 85-92% heat recovery efficiency.
- PIV (Positive Input Ventilation): Nuaire Drimaster Eco Heat, EnviroVent ATMOS, Vent-Axia Pure Air Home — condensation control for retrofit.
- dMEV (continuous extract): Vent-Axia Lo-Carbon, Greenwood CV2GIP — whole-house background ventilation for new builds.
- Bathroom and kitchen extract: Vent-Axia, Manrose, Xpelair — humidity-sensing, run-on timer, low-noise.
- Commercial AHU: Daikin, Mitsubishi, Wolf, Swegon — offices, retail, restaurants, education.
- Kitchen extract canopies: for restaurants and hospitality — bespoke design and install.
From-prices for Kent in 2026.
Starting prices vary widely by building type, ductwork accessibility and air-flow targets.
- PIV loft install (3-bed home): from £600 installed
- Bathroom extract fan upgrade: from £180 installed
- MVHR retrofit (3-bed home): from £3,500
- MVHR new build (3-bed, first-fix): from £3,000
- Commercial AHU (small office): from £6,500
- Annual MVHR service + filter change: from £125
See our MVHR vs PIV comparison for which system is right for your home.
Part F, Part L, new-build & retrofit.
Building Regulations cover ventilation explicitly:
- Part F (Ventilation): mandatory mechanical extract in bathrooms and kitchens. New builds and significant refurbs (more than 30% of glazed area replaced) need balanced ventilation — effectively MVHR or whole-house dMEV.
- Part L (Conservation of fuel and power): heat-recovery efficiency targets for MVHR; tested at commissioning.
- Air-tightness testing: required for new builds, with corresponding ventilation provision.
- SAP calculation: energy modelling uses your ventilation system’s specific fan power and recovery efficiency.
We provide commissioning reports for Building Control sign-off and SAP inputs for the energy assessor.
Ventilation across Kent & South East London.
Retrofit and new-build MVHR work across our full coverage area, plus commercial AHU installs in offices, restaurants and education sites from the Sevenoaks workshop.
More on ventilation.
- MVHR explained for UK homes — mechanical ventilation with heat recovery — how it works, install cost, Part F compliance.
- MVHR vs PIV — side-by-side comparison — which ventilation strategy is right for your home.
Frequently asked questions
What is MVHR?
MVHR (Mechanical Ventilation with Heat Recovery) is a balanced ducted ventilation system that supplies filtered fresh air to habitable rooms and extracts stale humid air from wet rooms. A heat-exchanger core recovers 85-92% of the heat in the exhaust stream and uses it to warm the incoming fresh air. Standard for airtight new builds.
Do I need MVHR or just better bathroom fans?
For airtight new builds, MVHR (or whole-house dMEV) is essentially a Part F requirement. For leaky older homes with isolated condensation problems, upgraded bathroom and kitchen extract plus a loft PIV unit usually fixes the issue at a fraction of the MVHR cost. We size the answer to the building.
How often do MVHR filters need changing?
Every 6-12 months depending on local air quality. In rural Kent during pollen season, six-monthly is realistic; in cleaner urban locations annual is fine. We include the first year of filter changes in the install price and offer annual service contracts thereafter.
Can ventilation be added to an existing home?
Yes. PIV is the simplest retrofit (a single fan unit in the loft, no ductwork). MVHR retrofit is more involved because ducts have to be run through ceiling voids, but it's achievable in most properties — especially during a re-plaster or extension project.
Will ventilation stop condensation?
Yes — that's the headline benefit alongside air quality. PIV stops it by gently pressurising the house, pushing moisture out through gaps. MVHR controls it by extracting at-source from bathrooms and kitchens before moisture spreads. Both work; the right choice depends on the building.
Ventilation
in the South East?
Free survey, fixed quote within 48 hours. Engineer-led — the person who quotes is the person who installs.
Request a quote- Direct line
- 07••• ••• 203
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