IVC FAQ™ is a series of questions and answers related to IVC systems and the modern technologies used for laboratory rodent housing systems.
2. Do the Lab Products individually ventilated cage (IVC) systems offer operators the option of adjusting cage air exchange rates? Why is the Lab Products cage ACH (air changes per hour) rate set at what some may consider to be too low?
Micro-Isolator® cages provide optimum airflow rates based in part upon the millions of cages in field use and over 20,000 ventilated system installations, spanning decades. We believe a more interesting question to be, “Why do some manufacturers’…
Operator airflow adjustments are unnecessary with Lab Products systems. Our racks are delivered ready to use by researchers, upon facility sanitization. These systems eliminate a situation where operators must determine when and how much to adjust the supply and/or exhaust airflow settings. It should be noted that resetting any airflow rate of any ventilated rack, should require the rack is then tested (calibrated) to certify the new settings, as a prerequisite.
As an example, each Lab Products Ventilated Housing System for mice is shipped factory set to provide an efficient and beneficial rate of 34 air changes per hour (ACH), with less than 0.2 meters per second of airflow velocity. This is considered a very low air velocity entering into a cage. The ACH rate is established based upon results from in- house, third party and reputable independent testing results that identified optimum airflow rates. Less energy is consumed as a result of the low ACH rate; the air supply fans do not have to operate as fast while HEPA filter and Pre-filter life are also extended as a result. Our customers find their HEPA filters typically last at least 5-6 years or more.
We offer a Cage Monitor unit that serves as a monitor/certification instrument, so you can verify cage ACH at any time, with any number of cages present on a Lab Products rack, with or without animals in cages. You can have your racks “self-calibrate”, taking only a few minutes per rack to complete a self-calibration process, even while a rack is populated with animals.
In contrast to Lab Products equipment, a number of competitor systems have cage airflow rates set as high as 60-100 ACH or more, and require a minimum number of cages be present on a rack at all times, to help avoid too much disruption to the supply/exhaust rates of remaining cages. The higher the supply airflow rates are, the higher the exhaust rates must be and in turn, this directly increases the rate and amount of particulate accumulation in filters (cage filters, blower pre-filters and HEPA filters,), change station filters, rack exhaust ducts and potentially, HVAC exhaust ducting and filters, requiring filters be changed much more often.
We are happy to work with any of our customers to determine alternate airflow rates for their Lab Products Ventilated Racks and Cages. Should a special need arise, please contact us at your convenience (800-526-0469 or firstname.lastname@example.org).
Additional questions or comments related to this posting? Please contact us and we’ll be happy to respond.
© 2015 Bio Medic Corporation. IVC FAQ is a trademark and Micro-Isolator is a registered trademark of Lab Products, Inc.
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3. Why doesn’t the Lab Products individually ventilated cage system require the use of exhaust fans and/or exhaust thimbles when connecting the racks to a facility HVAC exhaust system?
The negative pressure Lab Products rack functions much like a large exhaust thimble, scavenging room air while capturing expelled cage air. The Lab Products air exhaust system functions totally independently from the air supply system. As the result, …
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© 2015 Bio Medic Corporation.