Performance of simplified ventilation systems.


Evaluating the compulsory performance checking of ventilation systems in Sweden.

The Swedish Parliament decided 1991 that ventilation systems in all non-industrial buildingsshould be regularly inspected in intervals from 2 to 9 years, shortest for schools, hospitals etcand longest for natural ventilated flats. The systems are checked to fulfil the requirementsgiven when installed.The goals of the evaluation were to give estimated rates for how many systems that wereapproved at the end of 1997 and the cause of the faults that made the system either not to beapproved or to be remedied before next inspection.The evaluation was made in three steps:1.

Performance Evaluation of four Ventilation Systems Regarding IAQ and Energy Use for Japanese Climate Conditions

The purpose of this paper is to evaluate the performance of 4 kinds of ventilation systems from the point of view of indoor air pollution and energy need during heating season under Japanese conditions by numerical simulation. TVOC was selected to characterize the indoor air quality impact to residents. The results show that in the case of mechanical exhaust ventilation system, TVOC level is the highest among all the systems. Mechanical central supply and exhaust ventilaton system shows its advantages for minimizing energy consumption and maintaining an acceptable indoor air quality.

Clarifying lab design. After much research, the National Institutes of Health can now provide a methodology for optimisation of laboratory hoods.

A research program was undertaken by the National Institutes of Health (NIH) to investigate ventilation performance of different laboratory configurations and their effect on the laboratory hood. The intention is to provide a basis for guidelines aimed at maximizing laboratory hood containment.

Checking the performance of ventilation systems.


Ventilation performance and indoor air quality in workstations under different supply air systems: a numerical approach.

This paper describes the results of a computational fluid dynamics study to assess the air freshness and percentage of dissatisfied people due to air quality in a partitioned office with different supply air diffusers. The numerical model involves the finite-volume approach of solving governing equations for mass and momentum, assuming that the buoyancy effects are negligibly small in comparison to the inertial effects. The k-s two-equation model of turbulence is used to predict the turbulence transport of flow properties.

Towards the determination of regional purging flow rate.

This paper deals with the description and determination of the purging flow rate, Ufor ventilation systems or equivalent flow systems. The regional purging flow rate and its use are discussed and proposed. By using the mass conservation principle, UP is embodied in various accessible mathematical expressions in terms of the transfer probability. Some UP-related parameters are described. A Markov chain model is proposed for determining the transfer probability and exploring several useful ventilation indices.