Indoor air quality (IAQ) is a general term relating to the presence of chemicals, physical and biological contaminants in the air within a building (indoor atmospheric environment)
IEQ is the quality of the parameters describing indoor environment such as temperature, noise, light, air quality, etc.
Building design and operation influence IEQ and human responses and thus indirectly affect the benefits of improved productivity. The effects of air temperature, ventilation rate, indoor air quality, light noise and individual control on performance and absenteeism are summarized in the following. As temperature, air quality and ventilation rate have been shown to affect the Sick Building Syndrome (SBS), the information is also given trying to link the SBS symptoms and performance. Furthermore, the potential impact of other factors related to indoor environment and the interactions between factors on the performance of office work is also discussed.
The effects of temperature on performance;
Room temperature affects the performance by several mechanisms;
- Thermal discomfort distracts attention and generates complaints that increase maintenance cost.
- Warmth lowers attention exacerbates SBS symptoms and has a negative effect on mental work.
- Cold conditions lower’s finger temperatures and so have a negative effect on manual dexterity.
- Rapid temperature swings have the same effects on office work as slightly raised room temperatures, while slow temperatures swings just causes discomfort.
The effects of indoor air quality on performance;
It seems reasonable to assume that people who do not feel very well when the air quality is poor will not work very well as well. Other possible mechanisms for an effect of poor air quality on performance include distraction by odors, sensory irritation, allergic reactions, or direct toxicological effect.
The effects of noise on performance;
Auditory information can be stimulus or a distraction. It is often the case in office buildings that noise from the conversations of others is a major irritant for workers, especially in open-plan offices. Complex cognitive tasks are affected by noise at 70-80dB(A). subjects read fewer words and made errors in proof-reading tasks while exposed to office noise at 80 dB(A) compared with 55 dB(A). studies show that open-plan office noise at 55 dB(A) reduces office work performance by 3% compared with conditions at 35 dB(A).
The effects of lighting on performance;
Theoretically it is likely that illuminance, amount of glare, contrast, seize of a visual subject and light spectrum influences the performance. Flickers from florescent lights with magnetic ballasts has been shown to reduce satisfaction and cause negative health effects. Proximity to a window is also an important factor with overall satisfaction of lighting.
Ref: REHVA, Guidebook No 6