Wet tissue cooling....

[Mr. Cucumber]

putting wet tissues and blowing air (this is actually not a joke)

is an interesting way to cool an IDLING cpu

[Levent]

by wet I assume you put those tissues in to freezer and grabbed them before they froze?

[Mr. Cucumber]

5 minutes ago, Levent said:

by wet I assume you put those tissues in to freezer and grabbed them before they froze?

I soaked the tissues in cold water and then spread them over a heatsink..then used a pretty strong table fan to blow air over the heat sink ... occasionally adding a few drops of cold water...

[Bananasplit_00]

sooooooo evap cooling?

[Mr. Cucumber]

2 minutes ago, Bananasplit_00 said:

sooooooo evap cooling?

phase change XD

[Windows7ge]

8 minutes ago, Mr. Cucumber said:

phase change XD

I figured that's what you were getting at. Now try it with alcohol. May result in better results.

 

Edit:

May also result in fire so isolate it and have a fire extinguisher nearby.

[Mr. Cucumber]

5 minutes ago, Windows7ge said:

I figured that's what you were getting at. Now try it with alcohol. May result in better results.

running this with no insulation is risky... wouldn't alcohol cause condesation... I tried using a vortex cooler back in high school...want to visit it again

[Windows7ge]

Just now, Mr. Cucumber said:

running this with no insulation is risky... wouldn't alcohol cause condesation... I tried using a vortex cooler back in high school...want to visit it again

Anything sub-ambient will cause condensation. Evaporating room-temp alcohol shouldn't be enough to pull water from the air. It's not like evaporating liquid CO2.

[Mr. Cucumber]

2 minutes ago, Windows7ge said:

Anything sub-ambient will cause condensation. Evaporating room-temp alcohol shouldn't be enough to pull water from the air. It's not like evaporating liquid CO2.

Yeah but still...  bit of Vaseline and some foam won't hurt...I think I'll post that very soon  ...thanks for the idea...

[SolarNova]

its called evaporative cooling.

 

its what bong coolers are, LTT done a vid on it a while ago, there are more up to date and more indepth vids on youtube explaining the idea, they work ..but they are LARGE.

[AngryBeaver]

21 hours ago, Windows7ge said:

Anything sub-ambient will cause condensation. Evaporating room-temp alcohol shouldn't be enough to pull water from the air. It's not like evaporating liquid CO2.

This isn't true. Condensation will only form if your temp is below the dew point. You can find your dew point fairly easy with any online calculator provided you know the temp and humidity of your room.

 

You could also just buy a cheap thermometer that gives you that information.

 

For example if your temp is 70f and you have 50% humidity your component temp would need to be below 50.5f for condensation to form.

[Windows7ge]

6 minutes ago, AngryBeaver said:

For example if your temp is 70f and you have 50% humidity your component temp would need to be below 50.5f for condensation to form.

For an average humidity there's really a 20°F delta before condensation starts to form? That's some substantial playroom...I could use this for my own experiments.

 

Makes me wonder if you forced the humidity lower just how much more could could get. Airtight a room (the best you can), dehumidifiers, and surround the socket with desiccate.

[SolarNova]

'Average' humidity differs from location to location even within the same country.

 

Non AC'd house holds for example can have a very varied humidity. While i know AC'd households are rather common in the US, in the UK they are not, and as such humidity can vary greatly.

The UK is generally considered to have a 'high' humidity at anywhere between 70% and 90% outside. Household humidity is somewhat different but is generally never at the ideal 40% point since we dont tend to use AC's. Its not unusual for most households to have humidity around 60% which is very close to the point that mold can start to become a problem, especially in older houses.

 

So taking 60% as the humidity level, and a household temp or 22c, the dew point is around 14c, only a 8c difference.

At the ideal range of 40% humidity at 22c its as low as 7c, a more comfortable 15c difference.

 

The next thing to consider is that the internal temp of a PC case is almost always higher than the ambient room temp, and as such u have to use that temperature instead of room temperature for you calculations. +5c over room temp wold be a good starting point.

 

In the end trying to get room humidity and temps just right to do sub ambient cooling is a big PITA and somewhat expensive, it would actually be cheaper and far more effective to just build a airtight case out of acrylic and a o-ring creation kit and some air hose fittings and then fill it with Nitrogen thus eliminating any moisture and making condensation impossible.

Thats actually what i intend to do when ever i finally get around to building my 24/7 subzero build.

[AngryBeaver]

9 minutes ago, SolarNova said:

'Average' humidity differs from location to location even within the same country.

 

Non AC'd house holds for example can have a very varied humidity. While i know AC'd households are rather common in the US, in the UK they are not, and as such humidity can vary greatly.

The UK is generally considered to have a 'high' humidity at anywhere between 70% and 90% outside. Household humidity is somewhat different but is generally never at the ideal 40% point since we dont tend to use AC's. Its not unusual for most households to have humidity around 60% which is very close to the point that mold can start to become a problem, especially in older houses.

 

So taking 60% as the humidity level, and a household temp or 22c, the dew point is around 14c, only a 8c difference.

At the ideal range of 40% humidity at 22c its as low as 7c, a more comfortable 15c difference.

 

The next thing to consider is that the internal temp of a PC case is almost always higher than the ambient room temp, and as such u have to use that temperature instead of room temperature for you calculations. +5c over room temp wold be a good starting point.

 

In the end trying to get room humidity and temps just right to do sub ambient cooling is a big PITA and somewhat expensive, it would actually be cheaper and far more effective to just build a airtight case out of acrylic and a o-ring creation kit and some air hose fittings and then fill it with Nitrogen thus eliminating any moisture and making condensation impossible.

Thats actually what i intend to do when ever i finally get around to building my 24/7 subzero build.

If we are talking liquid cooling here then there are several ways to use something like a raspberrypi to calculate dew point and flip on and off the condenser on say a chiller. 

 

Then you have insulation in the water lines which acts as a buffer between the liquid line and outside air so that condensation also doesn't occur because the insulation temp is between the water and ambient air temp. Since the point that open air touched the surface is where condensation occurs.

 

Now in the way of a swamp cooler (what a bong cooler is) you are relying on evaporation to reduce the temp if the liquid. The downside is the need for constant filling and it adding humidity to the air. Then again it becomes less effective the more humidity you have which means it can't actually get down cold enough to create condensation in 99% of cases. It is technically a phase change setup, but as it is not in a vacuum it doesn't have the same capabilities and concerns as say an AC.

[raraslopcsw]

On 8/18/2019 at 4:45 PM, Windows7ge said:

I figured that's what you were getting at. Now try it with alcohol. May result in better results.

 

Edit:

May also result in fire so isolate it and have a fire extinguisher nearby.

this is.. the tissues in cold water and then spread them over a heatsink.

[Windows7ge]

44 minutes ago, raraslopcsw said:

this is.. the tissues in cold water and then spread them over a heatsink.

*confused* What?

[AngryBeaver]

On 8/19/2019 at 6:55 PM, Windows7ge said:

*confused* What?

So the theory is you drape a damp clock on your heatsinks and with fans blowing threw both the evaporation will lower the air inside the cloth by a few degrees.

 

In practice I don't think it would work well plus you are adding a source of possible water directly above your motherboard and CPU socket.

[Windows7ge]

10 minutes ago, AngryBeaver said:

So the theory is you drape a damp clock on your heatsinks and with fans blowing threw both the evaporation will lower the air inside the cloth by a few degrees.

 

In practice I don't think it would work well plus you are adding a source of possible water directly above your motherboard and CPU socket.

The thing I'm confused about is I'm saying to try it using alcohol instead of water because OP said he used water but it seems raraslopcsw thought it was alcohol hence he's telling me "it is.. "?

 

That's what I'm confused about. Not how the process of phase change cooling works.

[Firewrath9]

I do this on my MBA 2012, as it gets quite hot (100c) even after a repaste, with my quiet fan curve, putting a cold towel under it drops temps 10-20c as it uses the aluminum chassis to sink heat.

[Mr. Cucumber]

23 hours ago, Firewrath9 said:

I do this on my MBA 2012, as it gets quite hot (100c) even after a repaste, with my quiet fan curve, putting a cold towel under it drops temps 10-20c as it uses the aluminum chassis to sink heat.

interesting soulution hmmmmm