One of the greatest detriments to the health of the computer environment is usually unseen. It is the concrete sub-floor deck. This floor carries the physical load of the data center while at the same time directs the conditioned air to the equipment that sits on it. Should this surface contain contamination, be it metal oxide, biological growth, or just lint and dirt, it will carry the particulate (as it is designed to do) to the various electronic units that it services. Of particular concern is when the concrete sub-floor deck is not properly sealed or encapsulated, or, if the seal integrity has deteriorated. Should the concrete not be sealed, the 'forever' curing concrete will emit crystalline particles produced by the efflorescence process. This is when the hydrated cement contains some calcium hydroxide as a product of cement and water. This calcium hydroxide is brought to the surface by moisture (50% humidity levels, or water condensation) combining with the carbon dioxide in the air to form calcium carbonate, which then appears as a white crystalline deposit. These crystalline particles are abrasive in nature and once airborne can endanger sensitive computer components.
They can also degrade minute moving parts and electrical contacts. An excessive quantity of silica can reduce the ability of microchips. If the seal has deteriorated, or is non-existent, we recommend sealing the sub-floor deck with a nonflammable acrylic sealer that produces a rock-hard finish, separating the concrete and above air plenum. Since there are a great variety of floor sealers, we recommend the use of one designed especially for the data center environment. The following is some general information regarding the product 'PARASEAL' and the importance of having a good concrete seal on your sub-floor deck:
Publication GC22-7072-1
"If your site is unusually dirty or has a chemical odor, you should be concerned. Dirt and corrosive gases can cause corrosion and possible equipment damage...The building floor should be sealed to prevent dusting of concrete."
Publication MM-108334-010
"Environmental conditions for the room environment must be maintained within the acceptable limits to prevent adverse impact on performance and reliability...Electronic equipment is sensitive to air contaminants such as ferrous metal slivers, dirt fibers, and concrete particulate from unsealed concrete...cement should be sealed to prevent the generation particles."
Publication MA5227
"The quantity of dust in the air must not exceed 0.39 gram/1000m 3[0.03 grain/1000ft3] maximum...The specifications for dust pollutants as per United States Federal Standard 209b...The primary floor must be poured concrete that
has been sealed to provide dust and humidity control."
Publication 9885-4920
"In order to assure reliability operation of the HDA and its filter system, the size and type of airborne particles must be controlled...The computer room should meet or exceed Federal Standard 209E...The subfloor area must be cleaned and sealed prior to equipment installation."
"The Seven Elements Every Manager Should Know About Computer Air Conditioning." - Liebert Corporation, "Halons And The Stratospheric Ozone Issues" EPA, Stephen O. Anderson, Ph.D., "What You Don't See Can Hurt You!" Infosystems Magazine, "The Slovenliness Factor" EC&M Magazine, "Data Center Design What Can Go Wrong?" Computerworld Magazine, "Indoor Air Quality" Engineered Systems Magazine, "Media Storage, Handle With Care!"
Data Management Magazine, "Dust, The Unseen Downer!" Insite Magazine,
For Additional Information please contact us at Paragon International.