Showing posts with label climate. Show all posts
Showing posts with label climate. Show all posts

Monday, May 16, 2011

New ASHRAE Temp/Humidity Guidelines

FYI, ASHRAE (American Society of Heating, Refrigeration, and Air-conditioning Engineers) has released new guidelines for temperature and humidity conditions for IT equipment. Among the changes (see p.8), are new classes A3 and A4, which allow 5C-40C and 5C-45C temperatures in data centers (respectively), along with 8-85 and 8-90% RH.

There are even guidelines for lower humidity level if certain procedures are followed.

--kb

P.S. Thanks to Pasi Vaananen for the heads-up.

Wednesday, April 29, 2009

Human Side of Higher Data Center Temperatures

With all the talk of hotter data center temperatures, one item that has often been overlooked is what happens to the poor soul tasked with going in and servicing equipment in that data center. Imagine having to work in a facility at 40°C (104°F) for several hours at a time--and that's at the equipment input. The exhaust temperature on the back side of the rack could easily be 55°C (131°F).

One approach is to adopt a "fail in place" model where technicians never go into a production facility, but even Google has technicians adding and replacing individual servers in their containerized data centers.

Other approaches to consider:
  • Localized spot cooling. A very small air conditioner could take the edge off the area in front of a rack.
  • Perform service operations at night or when it's reasonably cool.

This last suggestion may seem too simplistic at first, but it's actually quite practical. In a facility with sufficient redundancy to ensure high availability, server replacement should be able to wait up to 24 hours. Operating a data center at consistently high temperatures will end up increasing power consumption in the IT equipment. It only makes sense to use higher temperatures in a data center when using optimizers to eliminate or substantially reduce HVAC CapEx and OpEx costs.

If a data center is using economizers, the temperature in the data center should drop when the outside temperature drops. Even in relatively warm areas during summer months, there are substantial times each day where the temperature drops to reasonable levels in which technicians can comfortably work.

--kb

Saturday, January 31, 2009

Temperature and Climate Data Around the World

One of the issues that affects the efficiency of data centers is the climate in which the data center is located. A well-run data center in Phoenix could draw more power than a poorly run data center in Toronto. When looking at measures of data center efficiency, it's important to consider these factors.

There's a nifty utility available from UCLA called Climate Consultant (see
http://www.aud.ucla.edu/energy-design-tools/tools/Climate4.exe or
http://www2.aud.ucla.edu/energy-design-tools/). This software allows you to draw
psychrometric charts, plot average/min/max temperatures, etc. for any location for which you have the proper type of weather file. For example, the graphic at the right shows a psychrometric chart for Hillsboro, Oregon.



Not only is this utility free, you can get weather data for many locations for free. The U.S. Department of Energy (DoE) maintains weather data for over a thousand locations around the world, including most airports at http://apps1.eere.energy.gov/buildings/energyplus/cfm/weather_data.cfm. For example, http://apps1.eere.energy.gov/buildings/energyplus/cfm/weather_data3.cfm/region=4_north_and_central_america_wmo_region_4/country=1_usa/cname=USA#OR provides data for several sites in Oregon. Just save the .EPW file to your local hard disk, and you're good to go.


Enjoy,
--kb

P.S. Thanks to Pasi Vaananen for the pointer to this tool.