Mitsubishi Electric has launched a new, CPD certified guide to illustrate how effective ventilation can help both the wellbeing of occupants and overall building efficiency.
“If the occupants of a building do not feel healthy and happy within that environment then they cannot be productive and this is true whether the building is an office, a shop, a hotel or a school,” explains Perry Jackson, General Manager of the company’s Ventilation Division.
A good ventilation system is at the heart of many aspects of occupant health and comfort. As well as providing a healthy atmosphere it also contributes to the heating and cooling of the building. Getting it right is therefore an important step to delivering a 'good' building.
There are several factors that affect how humans react to their indoor environment, including access to daylight, type of lighting, temperature, space and indoor air quality.
CIBSE (Chartered Institute of Building Services Engineers) defines good indoor air quality as air with no known contaminants at harmful concentrations. These include volatile organic compounds (VOCs) that are released from carpet glues; carbon dioxide from occupants; odours and other particulates. Minimising and filtering these is important but occupants also need to have a sense of 'freshness' which means keeping CO2 levels to a minimum as well.
Part F of the Building Regulations (2010) deals with ventilation in buildings. For non-domestic buildings the required rate of ventilation is 10 litres/s per person.
However, this is described as a moderate to medium level of air quality and other guidance suggests that for a high standard of indoor air quality, a ventilation rate of 15 litres/s per person is more appropriate (BS EN 13779 Ventilation for buildings).
“Ventilation can also impact on internal space temperatures,” adds Jackson. “Higher ventilation rates may increase air quality for occupants but could actually cause drafts.”
Designers also need to take into account the effects of both latent and sensible heat which can help keep the indoor climate less dry and more comfortable whilst reducing heat losses – leading to savings in both energy and running costs.
“Stricter regulations are demanding highly insulated, energy efficient buildings and there is now a pressing need for fresh air in today’s modern premises,” says Jackson. “This new guide examines the different options available to designers and their effectiveness within different types of buildings.”