Most standards for air handling systems prescribe a minimum air flow rate per person per hour based on full occupancy of the ventilated space. The number of occupants may fluctuate widely, however, and demand-controlled ventilation (DCV) responds to the actual demand for air renewal. There are now sensors capable of detecting this demand, and these are a prerequisite for DCV and good air quality. Key features of DCV are the incorporation of thermal tolerance bands (heating/cooling, humidification/dehumidification), and special control strategies to reduce or even disable the air flow rate.

The performance and effectiveness of any ventilation and cooling strategy depends largely on the method of air distribution and heat removal system. The consequences of poor air distribution and cooling systems are draughts, air stagnation, large temperature gradients and radiation asymmetry. These factors are the chief cause of the occupants' dissatisfaction with their thermal environment, and are major contributors to the so-called 'sick building syndrome'. Cooled ceilings combined with displacement ventilation, sometimes known as 'comfort cooling', has gained popularity in recent years.

Today, laws and regulations play a major role in just about everything we do. The declining quality of the air in our buildings is causing movement towards regulations relating to how buildings should be designed and operated. It is important that designers and operators are aware of all current design and operating standards. ASHRAE Standard 62, "Ventilation for Acceptable Indoor Air Quality" developed in l 989 and now under revision, has created new challenges for designers and engineers.

It is known that water mist occasionally fonns near ice surfaces in roofed skating facilities depending on the indoor environmental conditions. The mist can lead to problems such as decreased visibility during skating competitions. The objective of the present paper is to clarify the relationship between indoor air conditions and water mist formation and to provide a useful design method for preventing mist formation in roofed skating facilities. In the first section, studies concerning the indoor air conditions for preventing water mist formation near the ice surface are described.

The paper deals with a research about analytical techniques for meaningful, reliable, cost-effective, in-situ, real-time and continues determination of airborne chemicals, by means of a new electrochemical sensor; the research aims to develop objective instrumental sensing systems able to substitute the subjective human responses. Sensor detection capability could regard a series of analytes: carbon dioxide, carbon monoxide, inorganic pollutants, ammonia and other metabolic gases, irritants, odours.

Assessing the perceived air quality in decipols by trained panels can be performed rather perfectly today. To calculate the olf load from these results is a little more problematic as one requires olf loads which can simply be added (linearly). The reason for this difficulty is the nonlinear relation between the perceived air quality in decipol and the pollution load in olf. The relation can be expressed by an exponential function in a range between l to 15 decipols. Unfortunately the exponent and the constant in the exponential function differ for different substances.