Standards Development

Scope

The proposed standard is the first part of a comprehensive series of international standards related to energy performance of underfloor air distribution systems. This standard shall stipulate the definition, terminology, technical specification and symbols related to underfloor air distribution systems. The new series of ISO standards will be composed of multiple parts as follows (tentatively). -

Part 1: Definitions, terminology, technical specifications and symbols

Part 2: In-situ measurement of room air stratification

Part 3: In-situ measurement of thermal decay

Part 4: Determination of air permeability of underfloor plenum This standard does not cover the conventional displacement ventilation system

Purpose

Because of a variety of potential advantages compared to conventional overhead (OH) mixing systems, such as improved occupants’ thermal comfort and indoor air quality (IAQ), layout flexibility, reduced life cycle costs, improved energy efficiency in suitable climates, underfloor air distribution (UFAD) systems have seen considerable increase in their use. Accordingly, nations around the world have developed and disseminated related technology and a part of technical specifications regarding UFAD system products have been adopted.

However, there are no existing international standards related to UFAD system and there are no existing work items related to UFAD in the ISO Community. Therefore, comprehensive series of ISO standards for UFAD including terminology, technical specification, performance measurement etc. should be established. To secure system performance, there must first be standards stipulating the terminology, technical specification and symbols related to UFAD systems. In addition, those standards shall provide the test method of room air stratification, thermal decay and air permeability of underfloor plenum, since air stratification and thermal decay, defined as the temperature rise of the conditioned air as it travels through the underfloor plenum, are the two distinct features that cannot be observed in the conventional OH mixing systems.

As for the performance of UFAD systems, energy consumption throughout the building’s life cycle must be taken into consideration. The proposed standards provide criteria regarding dynamic analysis and will make analysis of the energy performance of UFAD systems possible.