[SOLVED] Acceptable temperature range and drastic temperature changes affecting health of computer components?

[Crag_Hack]

Hi I am wondering about acceptable temperature range and drastic temperature changes affecting health of computer components.

In Scott Mueller's Upgrading and Repairing PCs 22nd Edition he says acceptable ambient outside temperature ranges for computers are about 60°F-90°F when on and 50°F-110°F when off. Also he says extreme temperature changes can harm computer components.

I am wondering if people agree about those ranges (my mobo didn't have a range listed in the manual).

Also I am wondering what kind of temperature change can cause damage to computer components. How extreme is extreme?
Should I avoid opening the sliding glass door a little in my room close to my computer when it is on and when the outside temperature is a certain amount different from the inside? (inside is usually 70°F-75°F and outdoor can be anywhere from about 50°F-85°F)
In my other house should I avoid walking outside briefly from the main house to the guest house at night with my laptop when the indoor temp is ~65-70°F and the outdoor temp is about 40°F-50°F or so?

Thanks so much!

 

[lvt]

Normal room temperature is OK (if you feel good it's good).

Humidity should be between 45%~55%.

 

[Eximo]

None of these things are a real concern.

The laptop has enough thermal mass (and it will be warmer than the environment it is in anyway) that taking it from room to room or inside to outside will have no real problems.

Operating a desktop or laptop computer in 90F conditions just means that cooling efficiency will be down. If the air is already full of heat. Heat transfer relies on something being cooler, if the components are cooler than the air, they will heat up until they are warmer than the air (if you ignore straight radiation) If your computer is already on, there is no harm in opening your door to the outside world.

Extreme humidity is about the only real concern. Non-gold plated contacts will oxidize (on the positive side (CPU, RAM, GPU etc, are typically gold plated) It is things like USB ports and HDMI cables that you have to be slightly more concerned about, in which case, get gold plated cables.

The only common thing to actually worry about:

Taking a cold computer (as in freezing) and turning it on.

1. That much thermal stress might damage thermal interfaces or crack PCB traces.
2. It will gather frost, which will melt and could cause a short.

So let your systems acclimate before use. If they do develop a frost let them dry out for a day or two.

 

[Crag_Hack]

Thanks guys.

@Eximo
What does 'the laptop has enough thermal mass' mean in laymen's terms?

Also are you saying as long as my desktop computer is already on there no danger of significant ambient temperature changes say -10-20°F harming the computer? How does thermal contraction and expansion not harm the computer in such a scenario?

 

[Eximo]

Again, it comes down to thermal mass. Temperature of an object is just a measure of the stored thermal energy in an object (molecular movement)

The air temperature is not going to immediately add or take heat away from anything all at once. Computers are made of metal, silicon, fiberglass, and plastic. These materials have a relatively high density. When they are warm, they will stay warm for a while. When they are cold they will stay cold. It takes time for the air molecules to swap energy with them.

If your computer is on, it will be warmer than almost any environment you throw at it. Call it 50C on average. That is 122F. Practically any ambient air temperature is less than this, so the incoming "hot" air is still cooler than the system. Since the system is running it will always be producing heat, it will always be warmer than the environment. So the computer is already at an 'expanded' state. It may warm up a little more since cooling efficiency will go down, but it will not be much more than it would normally experience just from varying loads.

A cold computer, on the other hand, when turned on is pumping heat directly into cold circuits and thermal interfaces. This means going from say 5C to 50C in a very short time, then you have to worry about sudden expansion. This is why computers tend to break when turned on, this is moment of the most stress on the components at any temperature.

 

[Crag_Hack]

@Eximo Thanks. So it sounds like speed of temperature change is the relevant factor. Go from hot to colder with an ambient temperature less than internal and it doesn't happen quickly enough to matter, but go from extreme cold to hot and it does. Right?

 

[Eximo]

@Eximo Thanks. So it sounds like speed of temperature change is the relevant factor. Go from hot to colder with an ambient temperature less than internal and it doesn't happen quickly enough to matter, but go from extreme cold to hot and it does. Right?

Sort of.

Extremes are a factor, but it is more the internal temperature of the components. A warm system will stay warm. A cold system that instantly has current pumped through it will heat up far faster than temperature transfer from an ambient environment.

Not to say it means instant destruction. Liquid nitrogen is often used in extreme overclocking. But they change thermal paste after a single session, and the hardware is risked through condensation and extreme temperature stresses.

 

[Crag_Hack]

@Eximo I see now, thanks.