Introduction

The provision of background ventilation via through-wall ventilators and window trickle ventilators is a cost-effective, non-mechanical means of introducing fresh outside air into habitable rooms. Easy to operate and fully controllable, natural background ventilators dilute and remove airborne pollutants (including odours) from rooms and control moisture to reduce the risk of mould growths which can be a health hazard to the occupants. For your convenience, we have outlined below extracts from the following regulations:

• National Retrofitting Scheme: NSAI SR54.

• Building Regulations 2019, Technical Guidance Document F.

• For detailed guidance, refer to the full technical documents linked above.

NSAI SR54: Code of practice for the energy efficient retrofit of dwellings

General:

• Provide controllable background ventilation in all rooms with external walls to the values set out in the following tables.

• Where Mechanical Extract Ventilation (MEV) is installed, provide background ventilation of at least 3,125mm² equivalent area per habitable room.

• Promote cross-ventilation with background ventilation of a similar area on each façade, where possible.

• Fit noise attenuating ventilators if an exposed façade is close to an area of continuous noise (e.g. a main road) – see Rytons Acoustic Background Room Ventilators.

Use table 31 for air permeability levels ≥5m³/hr/m²

Use table 32 when air permeability is expected to be <5m³/hr/m²

Technical Guidance Document F: Ventilation

Background ventilators

General:

• The guidance is only for dwellings with air permeability between 3m³/(h·m2) at 50 Pa and 5m³/(h·m2) at 50 Pa, as Technical Guidance Document L sets 5m³/(h·m2) at 50 Pa as the upper limit for air permeability.

• Promote cross-ventilation with background ventilation of a similar area on each façade, where possible.

• Fit noise attenuating ventilators if an exposed façade is close to an area of continuous noise (e.g. a main road) – see Rytons Acoustic Background Room Ventilators.

Rytons Background Ventilation Range

Achieve compliant background ventilation in habitable rooms with Rytons controllable through-wall background ventilators or a combination of window trickle vents and through-wall sets.  We are always happy to assist you with ventilation calculations and product selection – call our technical sales office on 00441536 511874 for advice.