Ventilation Systems
MVHR | Single Room | Commercial | Surrey, Sussex & South London
Air conditioning keeps your building cool — ventilation keeps the air healthy. Modern well-insulated buildings trap CO2, moisture and pollutants without adequate ventilation. AirCon Doctor install ventilation systems for homes and businesses across East Grinstead, Surrey, Sussex and South London, from single-room extractor units to whole-house heat recovery ventilation.
Why Ventilation Matters
A modern well-insulated home — or an air-conditioned building with windows closed — accumulates CO2 from occupants’ breathing. Above approximately 1,000ppm CO2, cognitive performance declines noticeably; above 2,000ppm, headaches and fatigue are common. UK offices routinely exceed these levels without mechanical ventilation. Adequate fresh air supply is not a luxury — it is a prerequisite for a productive, healthy environment.
Moisture is the other critical factor. Every person in a building releases approximately 40-70g of moisture per hour through breathing and perspiration. Cooking, showering and clothes drying add significantly more. Without ventilation to remove this moisture, relative humidity rises and condensation mould develops on cold surfaces — particularly in kitchens, bathrooms and north-facing bedrooms.
Mechanical Ventilation with Heat Recovery (MVHR)
MVHR — sometimes called heat recovery ventilation or MHRV — is the most efficient whole-house ventilation solution. A central unit extracts stale, moist air from kitchens, bathrooms and utility rooms while simultaneously supplying fresh filtered air to bedrooms, living rooms and home offices. A heat exchanger transfers 85-93% of the heat from the extracted air to the incoming fresh air — so you get constant fresh air without the heat loss of opening windows.
MVHR is standard in new Passivhaus and low-energy homes and is increasingly being retrofitted into older properties, particularly where air conditioning has made the building more airtight. We specify and install Mitsubishi Lossnay and Daikin VAM heat recovery units for both new build and retrofit applications.
Typical installed cost: £3,500 – £7,000 for a residential whole-house MVHR system.
Single Room Ventilation
For kitchens and bathrooms, a single room mechanical extract unit — triggered by humidity or a wall switch — is the standard solution. For home offices and bedrooms without opening windows, a through-wall positive input ventilation unit or a single-room MVHR unit provides fresh air without heat loss.
Typical installed cost: £150 – £500 per room for single extract ventilation.
Commercial Ventilation
Commercial buildings are subject to Part F of the Building Regulations — minimum ventilation rates based on occupancy and floor area. We design and install commercial ventilation systems for offices, meeting rooms, restaurants and retail premises that meet regulatory requirements and maintain air quality for staff and customers.
We combine ventilation design with air conditioning specification — the two systems need to work together. An office with air conditioning but inadequate fresh air supply will still have poor air quality; an office with ventilation but no temperature control will still be uncomfortable in summer. We design integrated solutions.
Ventilation Combined with Air Conditioning
Mitsubishi Electric’s Lossnay and Daikin’s VAM units integrate directly with their respective VRF commercial air conditioning systems — fresh air is pre-conditioned before entering the building, reducing the load on the air conditioning system. For new commercial fit-outs, we specify integrated air conditioning and ventilation from the outset.