Garage heat extraction

[ericmark]

I have many times tried to cool a room, and come to the conclusion best option is not to heat it. Had it will a caravan and fridge, fitted fan behind fridge, if on the caravan stayed reasonable heat, however if I waited for caravan to get warm, the fan would never cool it down.

Your problem is any attempt to box in the server and if then the fan fails it could really over heat, it depends on the position, but if I could use a 12 inch fan rather than a 4 inch fan I would, as then if fan fails there is still a reasonable hole for the chimney effect to still keep everything cool.

 

[endecotp]

Measure the electrical power used by the computers. (Say it is 100W, = 0.1 kW = 0.1 kJ/s).
Divide by the specific heat capacity of air (which conveniently can be approximated as 1 kJ/kgK) to get say 0.1 kg K / s.
Divide by the temperature increase that is acceptable; say 10 C, to get 0.01 kg / s.
Divide by the density of air (conveniently also about 1) to get 0.01 m^3 / s = 10 l/s or 36 m^3 / hour.

Substitute your numbers and compare with what your choice of fan claims to achieve.

 

[ban-all-sheds]

 

[EFLImpudence]

if fan fails there is still a reasonable hole for the chimney effect to still keep everything cool.

Sooooo -

are you saying the fan is not really necessary?

 

[John D v2.0]

The modern name for that is a passive stack ventilation systemsame principle, trendy name

 

[ericmark]

Sooooo -

are you saying the fan is not really necessary?

He has already said the servers are not too hot, it is the people in same garage which have a problem, what one does not want to do, is fit barriers and ducting which means the fan is then needed to keep the servers cool enough, so if fan fails, so do servers.

A standard bathroom fan is not really a quality item, they do fail even with just 15 minutes use per bathroom visit, compare that to the fan in my computers, which have run for years without problem. A fan like this

at around £9 is reasonably reliable, but at 12 volt DC not really an option, the bathroom fan is around 4 times the power and also price, but it in the main has simple bush bearings not the roller race of the computer fan and you are likely to have it fail within a year of full time use.