Buildings HVAC system

Condensation of water on cool indoor surfaces (e.g., windows) may damage materials and promote the growth of microorganisms. The presence of humidifiers in commercial building HVAC systems has been associated with an increase in various respiratory health symptoms. 

Heating. Ventiiation. and Air Conditioning i(HVAC) Systems. The design professionai should evaluate building HVAC systems and sub-systems and select major HVAC equipment components based on a consideration of health and safety requirements, initiai costs, operating costs, and maintenance costs,... 

The effects of high and low air temperature on the plant and equipment, in particular safety critical electronics and HVAC systems. The Auxiliary Building HVAC system is required to maintain the ambient temperature within the rooms which house the Class 1 equipment to within their acceptable operating range. The extreme ambient temperature could have an impact on the HVAC systems ability to provide this function due to it... 

The Radwaste Building HVAC system serves the Radwaste Building which includes the clean electrical/mechanical equipment room and the potentially contaminated HVAC equipment room, the packaged waste storage room, the waste accumulation room, and the mobile systems facility. 

The Radwaste Building HVAC system must collect the vented discharges from potentially contaminated equipment. 

The Radwaste Building HVAC system must maintain the radwaste building at a negative pressure with respect to ambient to prevent unmonitored releases from the radwaste building. 

The other accepted detector is the sampling t) e detector. These differ from conventional sampling duct or HVAC detectors found in office building HVAC systems. They are much more sensitive than the ordinary photoelectric or ionization type detector. These detectors have the capability of detecting smoke obscuration in the range of 0.03-0.003%. These detectors can be very successful as early warning devices when used in the return air plenum of the cleanroom air handling system. They can be set for multiple levels of sensitivity. The first level could sound a pre-alarm and a second level could shut down room recirculation and initiate exhaust. 

To measure the particles concentrations in the workplace air, the Dust-Trak TM Aerosol Monitor (model 8520) was used, which is the reference equipment for sampling and measuring indoor air quality under buildings HVAC systems regulation. This equipment measures the fine and coarse particles concentration by weight (PM, <1,0 im, PM2 5 < 2,5 p,m and PM, < 10,0 jim). In this study, the i (xm nozzle was used with the aim to detect particles with lower dimension than those of the applied sand. The established maximum concentration limit in Portugal is 0.15 mg m for particles smaller than 10 (im. (M.O.P.T.C., 2006). 

Acoustical Louvers. Acoustical louvers are used in building mechanical systems when exterior walls are penetrated for fresh air intake, exhaust, or rehef air, in situations where the impact of HVAC noise is of concern in the surrounding environment. The louvers consist of a series of hoUow sheet metal blades. The bottom faces of the louver blades are perforated and the blades are filled with fibrous sound-absorbing material. Typical acoustical louvers are 20 cm (8 in.) to 30 cm (12 in.) in depth. The amount of insertion loss they provide is limited. 

Indoor air contaminants can originate within the building or be drawn in from outdoors. If contaminant sources are not controlled, problems can arise, even if the HVAC system is properly designed and well-maintained. Sources can be from outside the building from operating equipment, from human activities, and other or miscellaneous sources. Sources outside a building include contaminated outdoor air, emissions from nearby sources, soil gas, or moisture or standing water. 

Commissioning reports Was the building properly commissioned when it was first constructed, including testing and balancing of the HVAC system ... 

Confirm that the HVAC system maintains appropriate pressure relationships to isolate and contain odors and contaminants in mixed use buildings and around special use areas. Examples of special use areas include attached parking garages, loading docks, print shops, smoking lounges, janitorial closets, storage areas, and kitchens. 

If the hypothesis or model does not seem to be a good predictor of what is happening in the building, you probably need to collect more information about the occupants, HVAC system, pollutant pathways, or contaminant sources. Under some circumstances, detailed or sophisticated measurements of pollutant concentrations or ventilation quantities may be required. Outside assistance may be needed if repeated efforts fail to produce a successful hypothesis or if the information required calls for instruments and procedures that are not available in-house. Analysis of the information collected during the LAQ investigation could produce any of the following results ... 

Identify key individuals needed for access and information A person familiar with the HVAC systems in the building should be available to assist the investigator at any time during the onsite phase. Individuals who have complained or who are in charge of potential sources (e.g., housekeeping, non- HVAC equipment) should be aware that their information is important and should be contacted for appointments or telephone interviews if they will not be available during the onsite visit. 

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