Computer Room Cooling In The Winter

November 22 2017 · 5 minute read · by NavJack27

It’s pretty much that time of the year here in the Northeast, winter. More than likely you’ll be running the heat in your house and if you’re like me you have a computer room that gets a little hotter than the rest of the house. I’ve struggled to figure this out for quite a bit and earlier this year we’ve had our house’s HVAC and insulation redone but we still notice the problem. The issue centers around the computers being heat sources in a second-floor room. Let’s walk through the thought process that I went through.

Heat rises, we all should know that basic fact. There are heat registers in the floor of this room and no return ducts. Two highly insulted windows are the other only openings. The ceiling is very low and above it is the attic which really has nowhere for hot air to go. As the furnace cycles on and off for the rest of the house the heat starts to build in this room. With the extra heat of computers in the room this quickly starts to climb. You could initially think that the solution would be to bring spot cooling into this situation with an air conditioner. Another idea could be to keep the door open for the air to circulate. These are good ideas, but they ignore the real issue here.

It’s best to look at a room as if it were a fish tank (room) filled with water (air). The water (air) is a fixed full amount in the tank (room). You get heated water (hot air) that flows to the top of the tank (room) from wherever the heat source is. You get cold water (cold air) which tries to stay near the bottom of the tank (room). Adding a water cooling device (air conditioner) will be fighting with the heat sources and the heat registers from the furnace. That chilled water (cold air) will be trying to go as low as it can in the room and it will also be looking for any way to spread out and escape near the floor. Also, the heated water (hot air) will be pushing down on the cooler water (cold air) in the room due to there being no place to escape up high in the room. I’m sure you are seeing the solution now I’d hope. We need to get the hot to expel itself from the room. Luckily, we have two windows in this room which have bottom and top openings. If you simply close the room and open the top of one of the windows as an exhaust you could cheaply solve this issue during the winter. If you want to spend a little money to make this better just get a window box fan and mount it in the top of the window blowing outwards to make sure that the opening acts only as an exhaust.

That is just the room cooling aspect of this. Next, we can appropriately approach proper computer cooling. I feel it’s correct to start with the CPU since that is the main thing in the computer that you normally alter the cooling method of. No matter if you are using water cooling or a big air cooler for the CPU you will be limited by the thermal conductivity of the heat spreader on the processor. For quite a while Intel has been using thermal paste on the inside of the heat spreader and this really limits the ability for the cooler to soak away the generated heat. This thermal paste works great for running at stock settings with stock voltages but at a certain point it limits the high end of an overclock. We’re going to first use the assumption that you have not replaced the thermal paste under the heat spreader. The example I’ll use here is my NZXT Kraken x61 since it has a liquid temperature sensor. When the processor has poor quality thermal interface material under the heat spreader you will notice that the liquid will not get all that hot in comparison to your CPU package temperature. That delta is very important in computer cooling. You generally want a small delta between room temperature and component temperature. The same applies with water cooling and the liquid to the CPU package delta and you can determine the weak point in your cooling by just finding out deltas. No matter how much you improve your cooling solution on a CPU with stock TIM it will never deliver an optimal situation. To achieve a better delta between your cooling solution and your component you need to do something called delidding. This process simply involves using some tools to remove the heat spreader from your processor and then cleaning the surface off and replacing the thermal interface material with something called liquid metal or just better thermal paste overall. Along with doing that another aspect that comes up is that the distance between the CPU die and the inside of the heat spreader. A byproduct of delidding is that you remove that sealant material that holds down the heat spreader. Even if the thermal paste isn’t much better it could just be that when you relid the CPU you have a tighter tolerance and less of an air gap. Once you do this to your CPU things should cool off way more evenly and the deltas should lessen.

If you apply these observations to your own situation I’m certain that you will achieve great results. Next, I’ll probably purchase a delidding tool and use it with my 8700k and write about my findings with it. I’ll also cover computer case airflow which I’ve omitted from this article due to me not using my case with the sides on like ever.