It is showed that side grinder produce significantly metal sheet dust onto the inner surfaces ofventilation ducts. New, cleaner installation method was developed in which shears are used asinstallation tools. The aim of this study was to carry out ventilation system installations atthree building sites with clean installation method and to collect information about operatingcharacteristics of the shears by interviewing assembly workers.The results of dust measurements showed that the average amount of dust on the inner surfacesof supply air ducts was very low in all three buildings.
Heating, ventilation and air-conditioning (HVAC) systems play an important role formaintaining a healthy and comfort indoor climate for buildings. Faults in the systems decreasethe performance and lead to higher energy consumption or lower thermal comfort level.Researches of the fault detection and diagnosis (FDD) on the building HVAC systems havebeen presented in recent decades. However, many of them use simulation tools or software tocheck the behaviour under the faulty condition. Few people introduced real faults into the realsystems to get the responses.
A cleaning concept consists of an evaluation procedure for estimating the need of cleaning, atheoretical model to design a rotating duct cleaning brush, cleaning methods and a verificationmethod of the cleaning result of HVAC system. The visual evaluation method with a videocamera and a display has been developed for a primary method to evaluate cleanliness beforeand after the cleaning work. The results obtained with the theoretical model of the brush werein good agreement with those obtained in the laboratory tests.
This paper is a review of occupant responses to localized (floor and desk mounted) airdistribution systems. These systems offer personal control, and can produce good ambientconditions, but few studies have examined their effects on actual occupants. A review ofeleven studies suggested these systems can lead to favourable occupant responses, which insome cases exceed those encountered using traditional mixing systems. However, most of thestudies included methodological limitations, which reduce the strength of conclusions that canbe drawn.
Subjective experiments were conducted in a climatic chamber to evaluate the effect ofindividual control of air velocity on productivity. For the condition of constant air velocity(CAV) subjects were not allowed to control air velocity and for the condition of preferred airvelocity (PAV) they were allowed to control it. The chamber was conditioned at airtemperatures of 31C, mean radiant temperature of 31C, and relative humidity of 50%. Severalcomputer tasks were given to the subjects to evaluate task performance.
A new derivation of productivity calculation model based on pollution loads and contaminantremoval effectiveness is applied and the effect of the improved ventilation efficiency onproductivity is estimated. The findings show that the proportion dissatisfied could be asuitable predictor of productivity loss due to indoor air quality in different kinds of officework. The proportion dissatisfied is possible to calculate from olf and decipol units. In a caseof one person per 10 m2 (0.1 olf/m2) and low-emitted material (0.1 olf/m2), the total sensorypollution load is 0.2 olf/m2.
In northern Europe ongoing changes in legislation that require increased levels of insulation,and the sealing of houses to reduce infiltration heat loss, has led to concerns about indoor airquality. As a result there is a need to achieve regulated and energy efficient winter ventilationin houses. The system currently being tested (WHOLE-pvs) in paired (test and control)houses and flats in Denmark, Poland and Ireland uses supply air windows in combinationwith Passive Stack Ventilation.
In time, ventilation ducts and accessories get dirty and this may lead to malfunction of ventilationequipment, fire hazard and especially a decrease in supply air quality. Repeated cleaningof the components can prevent these adverse effects. The frequency of cleaning dependson how easily different components get dirty.
The ventilated ceiling is a flexible solution for kitchen ventilation where the heat loads arerelatively low and aesthetics is a concern. The use of hoods is an ideal solution for locallyhandling contaminants produced in concentrated areas. Thus, special attention should betaken on the ventilated ceiling which removes air at the ceiling level. The simulationsconducted show that the capture jet improves the total effectiveness of the ventilated ceiling.Indoor air quality is enhanced in an energy efficient manner.
The traditional ways of maintaining cleanliness, temperature and moisture level in anoperation theatre (OT) usually use larger HVAC system and keep both the heating andcooling functions operating at the same time. The temperature and moisture level are thusunder control at the cost of tremendous amount of wasted energy. Incorporating the HVACsystem with the newly developed secondary return air system, the system capacity can bereduced while the energy efficiency can be increased. In this paper, concepts of the secondaryreturn air system are described.
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