Copyright (c) 2010 Alison Withers

The quality of air in a building can influence the productivity and health of its occupants and on energy costs.

Nowadays public awareness about the effects of over exposure to poorly maintained working environments is widespread.

Working practices are typically more sedentary with employees often spending long periods working at a single location or work station. It is therefore important that staff feel comfortable in their workplace.

Failure to provide pleasant surroundings may result in hugely expensive staff turnover and absentee problems.

For people to work efficiently they need adequate levels warmth, lighting and noise control in pleasant and clean surroundings, with sufficient quantities of fresh or purified air.

A significant proportion of contaminants in indoor air gets into buildings through the ventilation system.

If the distances between filters in incoming air ducts are too far apart impure air may flow past them.

Even if they are not filters cannot get rid of every contaminant from the outdoor air.

Some will still enter the system and build up on the inside of the ventilation ducts or even mix with the incoming air to get into the building itself.

If over time the condition of an air handling system deteriorates it will lose efficiency and there is a risk that dust particles will get through the system and end up on equipment, such as computer, and on furnishings and decor.

The reduced efficiency of the air-flow can also lead to increased energy consumption especially as system components can become clogged up and potentially fail to work.

Building managers are required by a number of regulations to ensure good air hygiene for users and occupants.

Regulations and guidelines relevant to ventilation system hygiene in the UK include the Work Place (Health, Safety and Welfare) Regulations 1992, and HVCA (Heating and Ventilating Contractors' Association) TR/19 Guide to Good Practice: Ventilation Systems' internal cleanliness.

They include various methods for testing the quality of the duct system that distributes the air around the building.

One of these is measuring the thickness of dust deposits on the duct surfaces inside the system, which can be a good indication of the system's cleanliness and also of its safety since dust deposits can become a fire hazard.

The HVCA's TR19 guide contains guidance levels for deposit levels and also actions that can be taken.

It also recommends distances between test points in ducting and recommends averages should be calculated to establish whether it is time to clean the system.

In addition to regular testing a regular regime of checking, cleaning and maintaining filters will help maintain good air hygiene and periodic checking of seals and joints will help ensure that the system is not working harder than it should need to and therefore adding to energy costs.

Significant cost savings and a healthier environment for the people usingt he building can be achieved with the help of a specialist commercial cleaning service to regularly test a ventilation system's air hygiene using the HVCA recommended standards and to them provide a regular maintenance and cleaning programme.