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Filters for the Xserve

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If you’ve ever been in a serious data center like the one where our servers reside at digital.forest, you know that all data centers share two features:

  • They’re loud. Running several hundred computers in a single room puts out plenty of noise, but more of the auditory attack comes from the massive air conditioning units necessary to keep all those computers sufficiently cool. It’s not as bad as standing near a jet engine, but there’s a reason the network administrators generally work in other rooms.
  • They’re clean. Data centers may not be as spotless as the clean rooms used by hard drive manufacturers, but dust buildup can cause hardware failures so there’s plenty of incentive to keep things clean. Those air conditioning units do double duty – they filter out crud in the air while dropping the temperature.

The noise of data centers is one reason Apple didn’t worry too much about the noise emitted by the powerful fans in the rack-mounted Xserve server – the Xserve simply adds to the din. Even though the latest revision of the Xserve is reportedly a bit quieter, it’s still louder than you probably want for your office, and those using the new Xserves for audio and video processing will probably still want to keep them in (properly ventilated!) soundproofed cabinets.


However, thanks to a small startup company called MacHEPA, Xserves can do more than just serve files and Web pages. Pop one or more of MacHEPA’s patent-pending HEPA (High Efficiency Particulate Air) filters into an Xserve’s unused drive bay and the Xserve will filter dust out of the air that’s drawn through the computer in the front-to-back cooling approach that’s necessary for rack enclosure. (MacHEPA is also working on a version for the drive bays in the Power Mac G4 (Mirrored Drive Door), also commonly called the “Windtunnel” for its excessively loud fans.)

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The MacHEPA filters cost $50 each, with replacement filter cartridges an extra $25. A filter cartridge should last at least a year, although the actual lifespan depends on how dirty the environment is. If you’re cutting sheetrock and spewing vast amounts of dust into the air, you’ll need to replace your filters more often. The truly cool bit? MacHEPA has managed to tie into Apple’s internal monitoring software so you’ll see blinking lights on the outside of the Xserve when the filter needs changing, and warnings also appear in the Blowers tab in Apple’s Server Monitor remote management application.


Although a MacHEPA filter probably won’t make much of a difference in a data center crowded with servers from other manufacturers, companies that standardize on the Xserve may be able to reduce their total cost of ownership significantly by installing MacHEPA filters instead of using expensive air conditioning equipment to filter the air. What about cooling? The Xserve’s powerful fans can keep the Xserve within its 95-degree F (35-degree C) operating limit in normal circumstances (and in extreme situations, the Xserve’s internal temperature monitoring will shut the machine down before any damage occurs). Put it all together, and you end up with a data center that doesn’t need nearly as much, if any air conditioning. This, of course, depends on the local climate – I wouldn’t try this in muggy Florida or the hotter parts of Australia, but realistically, those areas will have a certain level of air conditioning in place to keep the humans comfortable.

An added benefit of the MacHEPA filter is better conformance with OSHA (Occupational Safety & Health Administration) guidelines for workplace safety relating to indoor air quality and occupational asthma.


Chuck Goolsbee, vice president of Technical Operations for digital.forest, said that digital.forest is considering creating an Xserve-only data center for Xserves outfitted with MacHEPA filters. Since the cost of maintaining that particular data center will be lower than normal, digital.forest plans to pass on the savings in the form of lower hosting fees for customers who use an Xserve/MacHEPA combination.


And besides, wouldn’t it be cool to use the Server Monitor remote management application to see just how dirty your server is from thousands of miles away? MacHEPA is just another reason our next server will be an Xserve.

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