The effectiveness of UV radiation lamps in order to reduce fungal contamination of HEPA filters, to extend filter efficacy and to reduce maintenance costs, is experimentally studied by means of a dedicated air conditioning unit. An experimental HVAC system, with HEPA filters and UV-C lamps (?=254 nm), was built. Two experiments were performed. After disinfection and control of airtightness, the internal surface of the HVAC system was contaminated (1) with A. niger spores and (2) with Actynomices. Temperature level was 300 K and Relative Humidity (RH) ranged from 30-90%.
Cleaning ventilation system ductwork has been a topic of controversy for several years. Guidance documents are available for duct cleaning, but uniformity in application of remediation and cleaning methods is inconsistent in many cases. Means and methods for cleaning range from high-volume negative pressure vacuum cleaning of residential ductwork ...to use of sanitizing agents on the interior of galvanized ducts...to ultraviolet germicidal irradiation for treatment of re-circulated air and control of infectious viral aerosols in operating room suites.
The sources of man-made mineral fibres (MMMFs) settled on furniture surfaces and in supply air were determined in an office building. The impact of renovation on indoor air and the perception of air quality by the occupants were studied. Renovation improved the air-tightness of the inner parts of structures. Settled MMMFs were collected with gelatine tape by pressure and deposition techniques. MMMFs in supply air were collected using the filter installed to the supply diffuser.
The relationship between construction activities and an increased risk of microbial contamination and degradation of air quality in new building construction and renovation projects was studied. Poorly designed or installed ventilation systems and inferior workmanship during construction were determined to have an adverse impact on the performance of the building ventilation system. This presentation will provide guidelines to protect HVAC system components during building construction and renovation projects and for building commissioning procedures for building ventilation systems.
Cfd-calculations were performed to test whether it is possible to separate a non-smoking zone from a smoking zone using an air curtain. The cfd-calculations resulted in the following conclusions: 1. A larger exhaust flow is best. 2. An air curtain with a low air curtain velocity and an air intake from the smoke zone (as opposed to an air intake from the non-smoking zone) has the lowest smoke concentration in the non-smoking zone. 3.
The subject of this paper is the numerical simulation of the capture of contaminants with a local exhaust system. The objective is to evaluate the influence of multi-slotted hoods on the capture efficiency and its impact on indoor air quality. The ventilation in the proximity of slots and the contaminant dispersion throughout the room were predicted using the commercial tool Fluent. Characteristics of the polluted air were examined for different geometrical opening configurations for a two-dimensional model. Two parameters were examined: the number of slots and the slot width.
This case study deals with the renovation project of ventilation system in the Natural Science Building of Tallinn University of Technology, covering the established aims and principles of technical solutions, in general, and results of monitoring. The reconstruction project involved the task of creating a new ventilation system for required indoor climate of laboratories, avoiding dissemination of harmful materials to rooms. In addition, it was required to keep the operations costs approximately at an acceptable level.
The current state of building services engineering in the healthcare sector is characterized by ambiguity and prejudice. There is a conflict, with inadequate knowledge of the necessity and effectiveness of ventilation-based protection concepts on the one hand with the associated investment and operating costs if an integral view is adopted and the economics of antibiotic prophylaxis and infection treatment costs on the other.
This article is part of a research in progress about comparative study methods for the Brazilian reality using among many other authors, Givoni (1969), Voght and Miller-Chagas (1970), Fanger-ISO(1970), ASHRAE (55-1992), Mahoney (1971), Humphreys (1978) and Olgyay (1962) methods. This research presents the principal concept to be evaluated by the Universal Fuzzy Controlled aiming to establish a reference to determine a possible interference of the acclimatization factor to determine thermal comfort.
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