Horse Sense #94

Computing and the Ergonomics of Heat and Dust

In this issue of Horse Sense:

-Computing and the Ergonomics of Heat and Dust


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Computing and the Ergonomics of Heat and Dust

What is the most important part of a computing environment?  The USER. 
After all, computers are just tools.  They only do what they are told. 
So, the number one thing that you can do to improve productivity is to make the environment fit the user.  There is more to it than just the speeds and feeds of your hardware or choosing the right piece of software, though they can make a big difference.  To improve productivity, you need to make it easier, safer, and more pleasurable for them to do their work.  Designing your environment to minimize user fatigue and discomfort and maximize user productivity is called ergonomics.  (See also <>, and <>).

So, what changes can we make that won't break the bank?

Temperature and Humidity

If the air temperature feels comfortable for the human, it is probably good for air cooled computer equipment as well.  For your equipment, air temperatures between 32 and 80 degrees Fahrenheit or 0 and 27 Celsius are fine.  65-75 degrees is considered ideal for a room temperature. 
However, room temperature and machine temperature may not be the same. 
Electronic devices, including the computer itself, generate heat.  If you cannot remove that heat, you will end up with a hot spot that will cook your equipment or even burn you.  So, make sure that vents are not blocked and there is lots of clearance for air movement.  If you are stacking lots of equipment together in a rack, you want to draw cold air in one side and blow hot air out the other.  You do not want the air flows to mix.  Cooling and racking equipment is an art form in data centers, but most users will probably just have to reposition their computers for proper air flow.  You may need to adjust your cooling system, add fans, or move equipment to avoid creating hot spots (discomfort zones if you are talking about people).  Newer equipment not only saves power but throws off less waste heat, which lowers your cooling costs and keeps hot spots from forming.  If your computer equipment feels warm or, worse, hot to the touch, you want to see if you can alleviate the problem.

Remember that your electronics may be operating at a different local temperature.  Even with decent air cooling, processors inside a machine are often operating above 40 degrees Celsius (over 100 degrees Fahrenheit).  Do not remove the heat sinks on your equipment and power it up.  The chips may burn out, melt, or even explode.  Be careful about touching anything inside a machine, especially if it is on.  Besides the hazards of electric shock or statically frying a chip, you could burn or cut yourself easily on some components. Do not take equipment from low to high temperature quickly if you can avoid it.  You especially do not want to take a freezing cold laptop or other piece of electronic equipment from a car trunk and then power it on in your office.  The thermal stress will be extreme and may cause the device to catastrophically fail.  Let the equipment warm up for an hour or so and then power it on.

Remember how I said that computing equipment tends to be air cooled? 
That can be a problem at higher altitudes and especially in unpressurized aircraft.  Power your electronics all the way down if they are going into an unpressurized cargo hold.  Hard drives require air so that their read/write heads can fly above the recording surface.  If the air is thin, this will not work and a laptop that is powered on in thin air will likely have a head crash and an unusable hard drive.  If you find it tough to breath, consider that your electronics might not operate well either.  If you need to use electronics at high altitude, make sure they are rated for that use.

Cool heads and necks promote comfort and good thinking.  If you get too hot, you get sleepy and your body spends a lot of effort trying to cool your brain and other organs.  Stay too hot for too long and you can suffer heat prostration or heat stroke.  If your head or neck gets too cold, blood is drawn from your extremities to keep your chest, head, and neck warm.  If your hands are stiff and you feel cold, simply wearing a turtleneck or scarf around your neck or a cap or hat on your head will promote blood flow back to your hands and let you type more easily. 
Ideally an office environment will be slightly cool so that you do not need to sweat to cool down yet warm enough that you do not have to wear turtlenecks.  But, each person is different.  I am a big guy and tend to run hot so I like a cooler office than my bookkeeper.  But, my office tends to be 6-10 degrees warmer than hers because I have more equipment in it and it is farther from the thermostat.  To compensate, I wear fewer and lighter clothes than she does.  In the summer, I often put a fan in my office to blow warmer air out of my room.

High and low humidity are the enemy of electronics.  Low humidity increases the chance of electrostatic discharge which will fry components and can give humans an uncomfortable jolt as well.  Low humidity also dehydrates humans and drains them of energy.  High humidity can cause electronic shorts.  It will also make humans very uncomfortable because they cannot sweat enough to cool themselves.  To check on the humidity, I use a large LCD weather station.  I have a sensor outside and one right next to my desk (which is also next to my rack of computers).  At a glance I can see what the temperature and humidity is and tell if it is too high or too low.  A common (but inaccurate) humidity indicator is a cold plastic drink in non-insulated glass, plastic, or metal.  If there is a little perspiration on the container, things are fine.  If you have a big puddle, the humidity is too high.  Big puddle is relative.  50% humidity is OK, and an iced drink will put a ring on your desk, but not a huge puddle.  If there is no moisture on the outside of the container, the humidity is too low. 
You want to invest in good climate control, including humidity control. 
But, if you cannot get it right now or you have issues in certain areas, try the following.  For humidity issues, use a humidifier or dehumidifier where you need it.  In a pinch, you can use a large open pan of water to humidify an area or wet towels on a rack.  If you have shock issues, anti-static fabric softener sprayed on the rugs will help as will antistatic chair mats (always recommended to protect your equipment, your carpet, and yourself).


Keep the dust down.  Put high efficiency air filters into your heating and cooling system.  Not only will they help people with allergies, they will keep computers from clogging up as well.  If you have a dirty environment, leave your shoes or switch shoes at the door to avoid tracking stuff all over.  Vacuum on a regular basis.  Fans that clog on power supplies, processor chips, and video cards cause computers to overheat and fail.  Sometimes those failures can even cause harm to the humans operating them if they touch a hot area.  Those fans are there to force air to flow next to hot components.  Unless the air is moving, the heat stays where it is.  Do not back your computers against a wall or otherwise impede their air flow.  Portable computers often have openings on the bottom, so putting them on lap desk coolers with fans are best and hard, flat surfaces are second best.  Carpets and tablecloths are bad for portables.  Set them on a newspaper, placemat, or other flat surface instead, but make sure they are on their rubber feet and have clearance under the laptop to provide for air flow.  A book is flat, but unless the feet can sit on the book, the air holes could be blocked. 
Clothing is not good for laptops and skin squishes, so I do not recommend actually using a laptop in your lap for an extended period. 
Your lap could get pretty hot.  It is easy to get burned if the burn comes slowly.  Portable computer fans are small and easy to clog.  If your computer is running more silently than it used to, the fan may not be spinning correctly and it could easily overheat.  My power supply fan on the back of my laptop got clogged and everything got very hot.  If your portable threatens to burn your leg like mine did, check out the fan.  I sprayed canned air over it and the dust almost choked me, but now my fan spins.  The portable is a little nosier, but it is a lot cooler.  I also use a USB lap desk cooler which has large quiet fans that remove heat from the bottom of my laptop and make it more comfortable to use.

Computers suck air through the case.  That means that you can end up with a lot of dust inside your computer.  Dust bunnies inside your case will kill your computer.  To keep the bunnies at bay, you want to vacuum off the air intakes to your case any time you see dust there.  Some servers use removable air filters that can be washed.  You might want to open up your computer at longer intervals and carefully vacuum it out without touching any components and then blow off dust with blasts of compressed air.  CD and floppy drives tend to accumulate a lot of dust in their inner workings, so make sure to blow them out.  Many of those drives fail due to dust clogs.  Almost all computer equipment attracts dust because it carries an electric charge.  Think of anything electronic as a dust precipitator.  You will need to vacuum or clean your computing equipment, especially the vents, more frequently than other furniture.

Do not smoke near your computer.  Computers will gladly suck up all that smoke and deposit it inside the case.  The tarry residue will shorten not only your lifespan, but the life of your computer.  If you must smoke while computing, use a smokeless ashtray to keep the smoke down.

Dust is attracted to almost anything electronic.  It will settle quickly on monitors and keyboards.   Roller ball mice tend to pick up dust and fibers and get clogged fairly often.  Keep your work area dusted and clean.  Never use ammonia based cleaners on your computing equipment. 
Ammonia will remove antiglare coatings from monitors.  Do not use Pledge or any other dust spray as they tend to leave residues.  Dry dust or use water with a non-abrasive cloth (like microfiber) on your equipment. 
For monitors, you can use eye glass cleaner sprayed onto the cloth, not the monitor.  Dish soap dissolved in water is appropriate for really bad cases of grime and grit; though make sure the equipment is off.  Then follow it with pure water and make sure it has had time to thoroughly dry before turning it on.  Isopropyl alcohol will clean and dry off wet (with water) electronic equipment.  Cotton swabs can help clean between keys on keyboards.  I have even taken keyboards outside to shake the crumbs and dirt out of them then scrubbed them with soapy water and rinsed them with a hose.  After letting them dry in the hot sun for a couple of days, they worked quite well and did not stick or malfunction like they used to when they had peanut butter, jelly, dirt, and Coke in them.  It was cheaper than buying a new keyboard and I liked the feel of the one I had, OK? (Grin)

Paper can create and hold a lot of dust, so printers and electronics around them can get dusty fast.  A lot of indoor dust is shed skin (ick), but you can track dust in.  Hair also naturally breaks and falls out.  This is especially true of the shedding dogs in my office.  Try to keep the hair out of your intake vents.  Brush your office dogs and cats frequently and vacuum up their hair tumbleweeds.

©2011 Tony Stirk, Iron Horse