Save money on your ducting by having Empire clean your ducts


The average particle removal efficiencies for each in-duct air cleaner are summarized in Table 4.1. The removal efficiency results for individual tests are tabulated in Appendix A. Note that because the downstream measurement was taken from a supply duct, the removal efficiencies reported here include filtration as well as deposition of particles within the AHU.

Removal efficiency was directly related to particle size for a given air cleaner. With the 1-inch in-duct filter, less than 1% of particles below 0.5 μm were removed, 3% of particles between 0.5 and 1 μm, 21% of particles between 1 and 3 μm, 55% of particles between 3 and 5 μm, 74% of particles between 5 and 10 μm, and 79% of particles between 10 and 20 μm. A similar trend was observed for each of the other in-duct air cleaners, although the range of efficiency across particle size bins differed among air cleaners. For instance, removal efficiency across particle size bins was most consistent for Trane CleanEffects™/American Standard AccuClean™ compared to other in-duct air cleaners, varying from 90.1% for 0.3 – 0.5 μm aerosols to 98.4% for 5 – 10 μm aerosols.
The nominal removal efficiency varied among air cleaners for a given particle size as well. The in-duct air cleaners ranked from highest to lowest removal efficiency for a given particle size are as follows: Trane CleanEffects™, EAC, 5-inch, and 1-inch. This
Environmental Health & Engineering Project #13603 Whole House Air Cleaning System Page #26
rank order is most apparent for the 0.3 – 0.5 μm size bin where the removal efficiencies are approximately 90%, 40%, 15%, and 0%, respectively. The differences among in-duct air cleaners were smaller for the larger particle size bins although the rank order was preserved.
4.2.1 Fine Test Dust
The average whole house particle removal rates determined from tests with the fine dust standard are summarized in this section. Results for the 10 – 20 μm particles are not presented because the particle number concentrations were low and could not be quantified precisely.
Overall, the greatest whole house particle removal rates among the in-duct and portable air cleaners were observed for Trane CleanEffects™. Referring to results based upon particle number concentrations measured by the Climet instrument near the HVAC return (Table 4.2), the average kac of 0.3 – 0.5 micron particles for Trane CleanEffects™/American
Standard AccuClean™ was 7.2 per hour (hr ). The next greatest kac in the 0.3 – 0.5 μm
range was achieved by the electronic air cleaner (4.6 hr ). A single HEPA-filtered portable
-1 -1
air cleaner (1.4 hr ) and an in-duct 5-inch filter (1.5 hr ) had approximately identical kac for
0.3 – 0.5 micron particles. Operation of 5 HEPA-filtered portable air cleaners produced a whole house removal rate (3.9 hr-1) for 0.3 – 0.5 micron particles that approached the performance of the EAC but was 3.3 hr -1 lower than Trane CleanEffects™. Representative decay curves for Trane CleanEffects™/American Standard AccuClean™ versus the other in-duct air cleaners and portable air cleaners are shown in Figures 4.1 and 4.2.
Examination of the remaining portions of Table 4.2 shows that Trane CleanEffects™/American Standard AccuClean™ achieved the greatest removal rate for each size category of particles. The 5-10 micron particle range was an exception where 5 portable HEPA units produced a particle removal rate slightly greater than Trane
CleanEffects . Operation of 3 portable ionic air cleaners yielded a removal rate that
ranged from 0 to approximately 1 hr  depending upon particle size.
Environmental Health & Engineering Project #13603 Whole House Air Cleaning System Page #27
WHCADR for each combination of air cleaner and particle size is also summarized in Table
4.2 and is directly related to whole house kac. In the 0.3 – 0.5 μm category, Trane CleanEffects™/American Standard AccuClean™ had an average WHCADR of 1,171 cfm, compared to the next highest WHCADR of 750 cfm attained by the EAC. Operation of a single HEPA-filter portable air cleaner produced an average WHCADR of approximately 230 cfm.
Detailed information on the particle removal rate and related parameters for each test are presented in Appendix D. As shown in Appendix E, whole house particle removal and clean air delivery rates determined from the APS measurements in the dining room were similar to those obtained from the Climet instrument with which it was collocated. Note that APS results for the 5 – 10 μm category are considered unreliable because of the low particle counts and small number of tests for which decay rates could be estimated.

If your home or buisness needs repairs. Don't hesitate to click on one fo the links at the bottom of this page. They will take you to a contractor that can help you out today.


Say goodbye to your problems.