Statistically Significant Efficiency Testing of HEPA Filters

Posted in: Air Filtration, Pork Insight Articles by admin on December 19, 2008 | No Comments

HEPA filter manufacturers must ensure that their filters are tested accurately and must do so in a cost efficient way. This study describes tests that tried to determine the minimum time required to provide statistically significant efficiencies of HEPA filters using a test system that is currently used in the production of the filters. 300 filters were tested. Poisson distribution was used to describe the variations and to find the upper and lower levels with 95% confidence. The results found that it takes 90 seconds for the test to ensure that a filter has an efficiency of 99.99% or higher at 95% confidence. For a new test system, software is suggested to calculate the confidence limits of the filters efficiency after each test cycle and then determine determine weather to continue testing.

Filters, filters, filters: Which one to choose?

Posted in: Air Filtration, Pork Insight Articles by admin on November 27, 2008 | No Comments

There are many different filters being produced by many companies around the world. This can make the decision to choose just one difficult. Scott Dee has written in this Pigletter about some of the filters he prefers. The scale for filters is called a MERV (minimum efficiency reported value)  which is a measure of how effective a filter is. The higher the MERV ranking the better the filter is, most filters used in research and in commercial barns are MERV 16, which is capable of stopping all particles over 0.3 microns in size. Although the PRRS particles are 0.05 microns, they travel on larger particles of dust or liquid that are usually 0.5-100  microns in size, making a MERV 16 filter effective. Dee has found through his research that a filter called Camfill Farr by the company Filtration Systems Inc. out performs any other filters from North America and the world. One drawback is that they can be expensive and may impede air flow if they are not a good fit with a barns current air flow system. Another suggestion by Dee is filters made by a company called Noveko. The unique thing about these filters is that they are coated with chemicals so that when contaminated particles move through the system they are killed. Understanding of filters is important for ridding a barn of PRRS, but sanitation should not be overlooked at all levels of production.

La Clinique Demeter et le Swine Disease Eradication Center: un nouveau partenariat

Posted in: Air Filtration, French Articles, Pork Insight Articles by admin on October 30, 2008 | No Comments

L’équipe de la CLINIQUE DEMETER est heureuse de vous annoncer sa nouvelle collaboration avec le SWINE DISEASE  ERADICATION CENTER de l’Université du Minnesota, l’un des plus importants groupes aux États-Unis en matière de recherche sur les maladies porcines. Le SWINE DISEASE ERADICATION CENTER est engagé sur la recherche, l’éducation, la certification reliées aux différentes activités qui touchent la santé et la production porcine, avec un domaine de spécification dans le contrôle et l’éradication des maladies, ainsi que dans le bien-être des animaux.

Filtration and air conditioning

Posted in: Air Filtration, Pork Insight Articles by admin on August 27, 2008 | No Comments

It has been proven and repeated that the PRRS virus can travel by air and this is being associated with PRRS outbreaks in negative herds. This has lead to a need for a better understanding of air filtration as the practice is being adopted by many facilities. Installing filters can be a large task requiring many filters and time to install them and change them with the season, but an alternative can be air conditioning which cools air year round making summer and winter filtration basically the same. Some barns who are using various styles of air conditioners include a recirculated air system which cycles air in the barn through the air conditioner, others uses various styles of fresh air systems, where air enters through the roof or through the side of the barn and shut off and turn on based on changing temperatures. Because air entering the barn is regulated and consistent year round one filtration system is required for winter and summer. The costs of putting in an air conditioning system range from around $300-600 dollars per pig. Most of these costs are associated with installation and renovation, the electrical set up on the farm, the type of air conditioner (recirculation is cheaper but requires more maintenance) as well as other factors. The cost of air conditioning is expensive but has potential to reduce the costs of purchasing and installing filters year round. Also with less air entering the facility the chances of PRRS infecting a herd may go down.

USE OF AN AEROSOL TRANSMISSION MODEL TO EVALUATE AIRBORNE SPREAD AND BIOSECURITY OF PRRSV TRANSMISSION AND MYCOPLASMA HYOPNEUMONIAE

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Mycoplasma hyopneumoniae is known to enhance the effects of the PRRS virus. By infecting a pig herd with epidemic levels of PRRS and M hyo, this study wanted to find out the meteorological factors that increases the spreading of PRRS and the efficiency of different air filters. Three sites that were close together were used: one infected with the PRRS virus and M hyo and two others ,the first with good filtration and the second with little to no filtration. This study did assessments based on quality of air samples taken over a two year period, and changing weather patterns. The study was still being conducted but has found that PRRS had been transported into the no filtration system but not the highly filtrated system. Assessing data of weather patterns found that PRRS in the air was more common on cloudy days, with low temperatures and high humidity levels. This suggests that weather plays a factor in the spreading of the PRRS virus.

Further assessment of fomites and personnel as vehicles for the mechanical transport and transmission of porcine reproductive and respiratory syndrome virus

Posted in: Air Filtration, Pork Insight Articles by admin on July 30, 2008 | No Comments

The project set out to re-evaluated the role of fomites and personnel as mechanical transporters and transmitters of porcine reproductive and respiratory syndrome virus (PRRSv) between pig populations. To test this swabs were collected from hands, boots, coveralls, cable snares, bleeding equipment and other fomites after they had come into contact with infected pigs. They were then compared to identical samples that were used on pigs  that were not PRRSv positive. Pigs who were PRRS negative were then exposed to the contaminated personnel and fomites and their blood was tested after they were exposed, they were then compared to pigs who were not exposed to fomites containing PRRSv. Results showed that pigs who were exposed to the PRRSv contaminated personnel and equipment became infected seven out of seven times while the non exposed group was not infected. It was proven that under the right conditions PRRS can spread between populations of pigs with fomites and personnel being the vehicle.

Effect of space allowance during rearing and selection criteria on performance of gilts over three parities in a commercial swine production system

Posted in: Air Filtration, Pork Insight Articles by admin on June 20, 2008 | No Comments

A large amount of gilts were used in this study to determine the effects of space allowance during rearing. The gilts were put into pens of equal size but with either 15 gilts or 22 gilts per pen. After this the pigs were evaluated on backfat thickness and loin depth, they also had their feet and legs scored. The age of puberty was recorded when it was detected, and reproductive statistics were taken. It was determined that space allowance had no effect on growth in rearing, backfat thickness or loin depth, total production or removal rate. Although pigs who were kept with more space achieved puberty at a younger age than pigs kept in a smaller space. Gilts that reached puberty at a younger age had better growth rates, greater backfat thickness and produced more pigs over parities 1 to 3 than pigs who reached puberty later in life. Despite what was expected, the faster growth in rearing did not effect removal rate. Also the faster growing gilts had more parities and weren’t removed as frequently after their third parity as slow growing gilts. Space allowance had no effects on total pigs produced or removal rate but gilts that had more space reached puberty sooner and produced more pigs over the first three parities.

To read this complete article please visit: http://jas.fass.org/

Aux grands maux, grands moyens

Posted in: Air Filtration, Pork Insight Articles by admin on November 16, 2007 | No Comments

Depuis I’apparition du Syndrome reproducteur et respiratoire porcin (SRRP) il Y a plus de 15 ans, nous avons appris a vivre avec Ie virus. Pourtant, tout n’a pas ete dit. Apreuve: les specialistes en la matiere se questionnent encore sur les modes de transmission de la maladie. Une idee nouvelle fait son chemin : Ie virus pourrait se transmettre par la voie des airs. Ceci modifie les modes de prevention qui sont mis en place. Le veterinaire Robert Desrosiers, un specialiste reconnu en matiere de SRRP au Quebec, croit qu’on ne peut pas eli miner ce mode de transmission de la liste des possibilites. « Malgre la biosecurite, Ie virus trouve souvent une facon….

Aerosol transmission of PRRSV: Is it time to start watching the weather vane?

Posted in: Air Filtration, Pork Insight Articles by admin on October 30, 2007 | No Comments

The spreading of the PRRS virus has recently been assumed to travel further in cold weather conditions. This was proven in past experiments and has since been considered the meteorological factor involved in PRRS spreading. Although it is true that cold weather is a factor in the survival of the virus it may  not be the only factor. The tests done to uncover weather factors involved a swine operation which was PRRS positive and 3 outlying facilities located 120 meters away in the direction of the prevailing winds. Two conclusions drawn from the research was that the virus was aerosol transported in all months except August and July and parameters other than temperature were a factor. It was noticed that air spreading viruses occurred not only in the winter but in the spring and summer months of April, May, and June. Also, meteorological parameters such as wind direction, relative humidity, barometric pressure and ultraviolet light index were found to be significant predictors of the PRRS virus in air. Although more work is required to legitimize some of these findings, producers can take away that prevailing winds should be a factor when deciding where to build new facilities.

ACTUALlTE: EUROVENT : Les filtres 11 air mis a’ nus

Posted in: Air Filtration, Pork Insight Articles by admin on October 25, 2007 | No Comments

ACTUALlTE: EUROVENT : Les filtres 11 air mis it nus 1 2>t1Ql2oo7
• Oepuis revrier 2007, la filtration de “air a rejoint la grande majorite des composants et des ensembles aerauliques en adherant aun programme commun de certification des performances. Etre certifie Eurovent, constitue une garantie pour “utilisateur.
1. Ce que contrOle EUROVENT :
. Le programme de certification Eurovent couvrent les filtres a poches. les fillres compacts et les panneaux des classes FS a F9, testes selon la norme EN779 :2002.