9. Noisy Systems

Switching the ventilation off, either through anxiety about running costs or perceptions of unwanted noise will result in a dramatic change to the internal environment of the home. A modern airtight low energy home must have adequate, controlled, ventilation and the system must be routinely serviced to maintain the good air quality.

 Noise can occur from:

• poor ductwork design (often the route is improvised);

• internal resistances (where duct runs are not straight);

• incorrect sizing and air speed/pressure;

• resistances in ductwork and filters;

• transmitted noise from poorly sited or installed units.

The ventilation industry, insurers and standards organisations have been developing guidance for domestic ventilation systems design and installation for over a decade. However, there are many components in a mechanical ventilation system and many people involved in the installation, commissioning and maintenance of all the parts.

Many of the problems experienced by social housing providers, who often inherit schemes through Section 106 agreements, arise because the householder expectations and understanding have not been anticipated.

The ventilation system and the consequences of its non-operation are not explained fully – increased humidity, stale air and condensation can all combine to make a very unhealthy home.

Things that can go wrong:

• Ventilation noise;
• Condensation and poor air quality;
• Increased asthma and bronchial conditions that are affected by humidity;
• Inhaled particulates, pollen and contaminants;
• Overheating.

Future-proofing recommendations:

• DESIGN: Design for easy operation, maintenance and repair (equipment accessibility);
• INSTALL:  Training and accreditation for ventilation and ductwork installation;
• COMMISSION: Set noise limits for internal noise and commission the system accordingly;
• MAINTAIN: Explain the correct operation and the importance of maintenance and filter changing.