This factor in the results was related to the fact that smoke particles tend to coagulate together in to larger particles as they grow older. According to Lougheed, “This suggests that your aging of smoking occurs faster than may be expected; in ductwork that occurs mostly within the starting metres” (p. 3).
The analysis from the HVAC surroundings filters suggested that there have been some specific considerations that needs to be taken into account when ever selecting air filter types and their positioning to avoid adversely affecting the efficacy from the duct-mounted smoke detectors. On this factor, Lougheed concludes that the keeping of air filter systems in return atmosphere ducts is usually not a concern; however , the writer emphasizes that, On the supply side, the duct smoke detector is placed after the oxygen inlet, the filter, the conditioning area, and the supporter. In this case, the filters could have an impact within the detection of fires (other than a flames in the filtration system itself), because they can reduce the smoke into a level where it is not a concern” (p. 4). In spite of this last mentioned constraint, Lougheed suggests that depending on the overall examine findings, duct-mounted smoke sensors will provide warnings in all those cases where smoke concentrations in the HVAC system reach those amounts established pertaining to safe building evacuation. In addition , other tests conducted by the researchers by UMD identified that sampling tubes were effective across the range of velocities that are generally found in HEATING AND COOLING systems.
Finally, the study of the sixty-five commercial buildings in the Baltimore/Washington area established that only two of the HVAC systems generated atmosphere velocities that exceeded the ideal air velocities established by the conventional test.
Limited and Justifiable Conclusions
In sum, Lougheed reports that (a) the necessity to turn off the HVAC program during fireplace events is justified as it “will reduce smoke motion through the HVAC system”; (b) the effectiveness of duct-mounted air sensors is not affected by smoking dilution and smoke maturing; (c) air filter types have an impact on the success of duct-mounted smoke detectors, particularly photoelectric detectors since they are not as sensitive to smaller diameter particulates contained in smoke cigars; (d) secure building evacuation can be achieved by using smoke cigarettes detectors in either the return system or the supply system. Beyond the foregoing, Lougheed also remarks that the study’s findings provide useful information concerning exactly where duct-mounted smoking detectors ought to be located and how well the duct-inserted sampling tubes