K&N Air Filter Efficiency Testing
Images Figure 1 Figure 2 Figure 3 Figure 4 In the indoor environment, settled surface dust often functions as a reservoir of hazardous particulate contaminants. It is also conceivable that significant variation in particle size of wind blown dusts would occur as a result of changing weather conditions. This allows you as the customer to test your products in real life situations in order to achieve product superiority. These particle size ranges are also used as the basis for evaluating ambient air quality by many state environmental authorities. Airmid Health Group, Trinity Enterprise Campus, Grand Canal Quay, Dublin 2. This will help alleviate any confusion.
Intensive carpet cleaning can be highly effective in reducing both surface allergen and airborne particle counts. A composite test soil with moderately elevated levels of certain elements e. Third: Examination of air floated dust from the Salt River Valley of Arizona reveals that it contains a high percentage of extremely fine particles, highly abrasive in nature, the size of which is difficult to arrive at by any screening specifications. It is now a three-number system. A secondary high angle lens system and photo detector gathers high angle scattered signal data from small particles.
However, this only involved the particle size 0. The slope or curve of this plot of size against Beta ratio will give a clear indication of overall filter performance, thus making for better evaluation. Occasionally, we send air filters out for testing with an independent lab, either to confirm our in-house testing or to reduce the capacity requirements on our lab. Thomas Caesar, give you all the relevant information. Standard Test Dusts are available to create an environment from the desert to the city, from gas pipeline to aviation fuel, from railways to aircraft.
While in a vehicle, an air filter will experience a range of operating conditions, airflow and dust feed rates, etc. The intent in producing a separate standard for the description of test dust was to provide a simple and accurate test dust reference for use in other standards or documents where test dust use is required. In this study, the particle volume distribution for household dust, is similar to that reported by Lewis et al. Every change requires an adjustment period because transition is neither quick nor easy. In parallel, airborne allergen levels also decreased significantly. The total number of particles deposited, however, was greater during the winter than during the summer. For others, it will be a bit more costly.
Test Dust can also be manufactured to simulate the range of Arizona Test Dusts and to meet specific requirements of the customer whatever the distribution and composition. Most filter manufacturers show the performance of their media graphically. As such, this is very much an indirect method to determine the cleanliness of feather and down and while it may measure allergen as a component of organic material present, an improved method which is more sensitive is required. Particle sources include skin, hair, mites, plant pollen, fibers, soil, road dust, cooking emissions, heating emissions and cigarette smoke Edwards et al. Certified values for particles sizes from 1 micron to 30 microns are provided. Particle size determination was performed at the Pharmacy Dept. The size distribution of the re-suspended dust particles is very important for acquiring the size fractional efficiency and loading performance of the filter.
Historically, filter manufacturers used a nominal or absolute rating, the latter giving the impression that filters with an absolute rating stop all particles larger than the quoted size. The prerequisite for each respective group is that a filter separates at least 50% of the corresponding particle size range. Graphs C and D indicate significant differences in particle size between the two types of dust. One of these samples was taken from dust originating in Salt River Valley, Ariz. Surface allergen measurements showed that the cleaning procedure reduced mean Derp1 levels from 92. In this system, the contamination level of a fluid could be represented using a two-number system. Graph C compares the cumulative volume average of the two types of Fine Test Dust.
The mass and loading of soil elements on the tiles following vacuuming were determined both by wet wipe collection and by subsequent chemical analysis. Airborne particle counts and surface and airborne allergen were measured in association with room disturbances and cleaning. Our goal is to design filters with the maximum possible airflow achievable while providing guaranteed engine protection. Dust samples were obtained from each home during a summer and winter collection period. The arithmetic mean mass deposition rate for all houses was 0. Edwards R, Yurkow E and Lioy P. Blended dust was analyzed to determine if specified particle size distribution was achieved.
In this study, a large sample of residential house dust was obtained from a commercial cleaning service whose clients were homeowners residing in the Raleigh-Durham-Chapel Hill Research Triangle area of North Carolina. Although house dust is heterogeneous, the particle distributions were remarkably similar for all dust samples tested in this study. Generally, the existing size distributions provided by the powder manufacturer are directly applied or real-time aerosol instruments are used to measure the particles. A Dust By Any Other Name Arizona sand has been used for testing filtration, automotive and heavy equipment components for decades. However, any filtration measurement will only be meaningful if it includes disclosure of the test variables that were selected, such as grade of test dust, airflow rate and terminal test pressure.
However, these adhesion forces may also occur with the test dusts currently used in vacuum cleaner testing. Some carpets act as a reservoir for allergen resulting in increased surface allergen levels, yet reduced airborne exposures during room disturbance. The real end-user benefit is the ability to easily differentiate between a good filter and a poor filter across the full particle size range rather than at one point; in other words, a poor caking filter can be determined more easily from the new data. The study utilized a 5 x 10 foot c. The nominal specific gravity is 2. The test protocol then measures the percentage of dust retained by the filter efficiency and the total amount of dust held by the filter capacity. The main interests were in sizing and counting particles.