ASHRAE Journal - December 2014 - 142

COLUMN DATA CENTERS

Creating a Perfect Storm
BY DONALD L. BEATY, P.E., FELLOW ASHRAE, DAVID QUIRK, P.E., MEMBER ASHRAE

In ASHRAE Technical Committee 9.9's Thermal Guidelines for Data Processing Environments,
the environmental guidelines for IT equipment inlet conditions extended the allowable
range up to 85% and 90% relative humidity (RH) and 75°F (24°C) dew point. However,
in an unconnected parallel move, international regulators banned the use of leadbased solders within the manufacturing of electronic equipment. The lead-based solder
has been replaced with silver-based solder. Unfortunately, silver, unlike lead, is more
susceptible to effects of corrosion when exposed to certain environmental conditions.
As a result, operating data centers at the higher
humidity levels defined in the allowable ranges in
Thermal Guidelines can have detrimental effects on electronic equipment reliability. This is particularly true
when the location has elevated levels of certain particulate and gaseous pollutants caused by today's industrial
and manufacturing activities.
The gaseous contaminants can act alone, in the presence of humidity, or in synergy with dust or each other
to corrode metallic materials. They can cause irreversible damage of circuit boards, connectors, integrated
circuits and various other electronic components.
The result is a perfect storm caused by the pursuit of
energy savings and environment-friendly materials in
the design and construction of data centers.

Background
The Restriction of Hazardous Substances (RoHS)
Directive 2002/95/EC was adopted in February 2003 by
the European Union and went into effect in 2006. The
directive restricts the use of six hazardous materials in
the manufacture of various types of electronic and electrical equipment.
Prior to this, electronic equipment was primarily manufactured with lead-based solder. In short, this directive
has restricted the use of lead in electronics and replaced
it by silver-based solders instead.
Silver is reactive when in the presence of elevated
humidity and certain gaseous contaminations including the following: Sulfur dioxide (SO2); hydrogen sulfide
(H2S); chlorine (Cl2); hydrogen chloride (HCl); nitrogen
oxides (NO, NO2); and ozone (O3).
142

ASHRAE JOURNAL

ashrae.org

D ECEM BER 2014

In recognition of these potential IT hardware failures,
TC 9.9 published a book entitled Gaseous and Particulate
Contamination Guidelines or Data Centers in 2011. This book
sought to introduce and warn the industry about the
potential for problems.
It also sought to establish collaboration between
related industry organizations to solve this problem
through research and information exchange. Those
industry groups include: ASHRAE; The International
Electronics Manufacturing Initiative (iNEMI); The
International Society of Automation (ISA); The China
Electronics; and Engineering Design Institute (CEEDI).

Energy Efficiency
During the development of the Contamination Guidelines,
there was aggressive industry activity focused on reduction of data center energy consumption.
The DOE had released its report to Congress indicating
the exponential rise in data center energy consumption.
This report was picked up by ASHRAE and The Green
Grid, who had published several white papers on the
PUE metric. This widely adopted industry metric had
resulted in a heightened awareness of the importance
of energy consumption data centers and was leading to
aggressive measures to reduce it.
One of the primary methods to improve PUE was the
adoption and deployment of economizers in data centers, including airside economizers.
By 2010, ASHRAE approved a significant change in the
Title, Purpose, and Scope of Standard 90.1 to include
Donald L. Beaty, P.E., is president of DLB Associates Consulting Engineers, in Eatontown,
N.J. He is publications chair of ASHRAE TC 9.9. David Quirk, P.E., is the chair of TC 9.9.

ASHRAE Journal - December 2014

Table of Contents for the Digital Edition of ASHRAE Journal - December 2014