Heat analysis in the home for computers

Heat and electronics don’t go well together. Heat from electronics is just a by-product of wasted electrical power that’s been transformed into heat by the device. It’s why computers have fans and sever rooms have AC.

The problem comes when you have a lot of electronics in your house because in England most people don’t have air conditioning installed to keep things cool and most English dwellings are smaller than those in Europe and defiantly smaller than the USA.   http://www.apartmenttherapy.com/average-home-sizes-around-the-151738

I’ve got a fair amount of equipment in a cupboard (well a room really its, 4ft sq) under the stairs in the centre of the house where my network patch panel is located along with the modem, switch and router. I recently added a second cabinet to keep all the power supplies in, my UPS and the Synology DS1812+ NAS.

Rack storage in under stairs cupboard

There is no real ventilation in this room, I end up leaving the door to the hallway open which helps but the Synology NAS does get quite warm under load.

Now I do have two LAN ports in the house loft along with power and there is loads of space. I was up there in April and it was freezing (April is usually a spring month in the UK but it’s been colder than average), well not literally, but it felt cold. So I bought a dual zone thermometer from eBay.  http://www.ebay.co.uk/itm/260651737416

It’s better than I expected really. It records to within 1c° and stores the maximum,minimum and average temperatures for that session as well as displaying the current temperature.

Here are the temperatures in deg C° for April 2012 for my upstairs and loft space above.

        Max    Min    Avg
Loft    24.8   8.4    12.3
House   20.3   16.6   19.4

I then moved the thermometer down to the under stairs room where the cabinet is located. The one other place where you might have a lot of free space that’s out of the way, dry and possibly cool is under the floor!

In my house we have a void of about 20” under the floorboards. When we renovated the house I made sure to clear a lot of the rubble and waste out from under there to avoid possible damp problems. I placed the probe thermometer in the void under the floorboards about 4” from the ground.

Temperatures for May 2012 ground floor cupboard and under floor void in degrees C°

             Max    Min    Avg
Under floor  16.8   16.2c  16.5
House        19.6   17.9   18.9


Loft: Pro
Excellent temperatures on cool days.
Out of the way, but still accessible.
Lots of space to located cabinet.
Loft: Con
Gets very hot on even mild days.
System noise can travel.
External ventilation methods costly.




Under floor: Pro
Consistent average temperature.
Keeps loft clear of equipment.
Security, who looks under there?
Under floor: Con
Dust, lots of dust!
Access, trap door needed.
You might have a solid concrete floor.




Conclusion – neither really works

So looking at the temperatures collected it’s obvious that living in northern Europe has made the loft space in winter (most of the year it seems in England!) an attractive option. The contrast is that on warmer days the lack of insulation between the external slate and roof void is such that you can reach worrying temperatures quickly and possibly into a critical range at the height of summer.

Under the floor does at first seem to offer many advantages. The temperatures recoded are much more consistent between cool and warm days thanks to the house insulation while remaining a good 4c°-5c° cooler than the normal living space. Utilising the space under the floor would also free up a large section of the cupboard for more day-to-day items.  However, with most equipment being actively cooled with fans the under floor consistency is only really suitable for passively cooled equipment that won’t be affected by dust build up.

Overall the relatively dust free environment of the home living space, ease of access and the fairly constant temperature of 18c° makes leaving my equipment where it is the best choice for me.

8 thoughts on “Heat analysis in the home for computers

  1. actually, in the us, i would go to the basement (under floor) looking for equipment before anywhere else in the house simply because it isnt living space, or adequate for a bedroom usually.

    1. Good point about using a basement if you have one. Very uncommon in the UK, which is a shame because they are so useful!

      Thanks, Niall

  2. How anyone could get away with running servers in a UK loft during the summer would be crazy. You could probably cook an egg off the cabinet surface.

    Is your top cabinet a 9U?

    1. We’ve had a good summer this year so probably!

      I think the top cabinet is a 6U, bottom one is 15U


  3. I have some equipment to store too and I was considering buying a cabinet. I was wondering how tidy it is on the inside, considering that I don’t have any rack items I want it to as tidy as possible.

    1. Geoffrey, you can get short shelves for the inside of comms racks that can make things tidier.
      You do still have some mess of cables unless you want to cut them down to length as required but that could be quite a job depending on the equipment and if it has moulded plugs etc…

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