Whether you’re working from home all day, gaming hard after work, or both, your computer will add a measurable amount of heat to your home. Here’s why and how to calculate exactly how much it will heat up a place.
Computers are surprisingly efficient heaters
Anyone who uses a computer knows that it generates heat. If you put the laptop on your lap, it will heat up quite quickly. Anyone who has gone on a gaming bender with a desktop computer knows that the room slowly warms up as you continue to sit.
So the idea of a computer adding some heat to the room it’s in while running isn’t necessarily shocking to most people. However, what is surprising to many people is how efficient computers are at converting electricity into heat.
Every single bit of electricity a computer uses (as well as all electricity used by peripherals like monitors, printers, etc.) is eventually released as heat.
In fact, assuming you set the heater to use the same amount of power as the computer, there would be no finite difference in room temperature between running the heater and the computer. Both use electricity to operate and both ultimately “discharge” waste heat into the room.
You can do the test yourself, but if you’d rather just read the results of someone else running a computer-to-heater match, you can rest easy knowing it’s been done. In 2013, Puget Systems, a personal computer company, conducted a fun test to see if a computer would actually work exactly as a space heater under the same conditions.
They loaded the computer with enough GPUs and hardware to match the performance of the basic small 1000W space heater they purchased for the experiment and tested them in a room isolated from the building’s HVAC system. The final result? Running a gaming PC under load to get as close as possible to 1000W produced an equivalent result in terms of increased ambient temperature.
We’re sure this comes as no surprise to physics students reading together at home. The electrical energy put into the system has to go somewhere, and it goes into the room as heat. Whether the source is an electric fan motor, a computer, a space heater, or even a toaster, heat eventually makes its way into the room.
Furthermore, we would argue that computers are—in a philosophical sense, not a strictly physical sense—even more efficient than a space heater. A space heater converts 100% of electrical input into heat and a computer converts 100% of electrical input into heat, but a space heater is limited to just heating or not heating.
On the other hand, the computer actually does all sorts of useful and interesting things for you, while also making the room a little toastier. You can run Fate for a lot of things, after all, but you can’t run it on your heater.
How to calculate how much heat your computer generates
It’s one thing to know that the electricity your computer uses eventually ends up as heat. Another thing is to find out exactly how much heat it is actually pumping into your home.
But there’s a wrong way and a right way to get to the heart of the problem, so let’s dive in.
Do not use the power supply rating to estimate
The first thing you should avoid is looking at the PSU’s power rating as an indicator of how much heat your computer is generating.
The power supply unit (PSU) on your desktop computer might be rated for 800W, or the fine print on the bottom of your laptop’s power cube might say it’s rated for 75W.
However, these numbers do not indicate the actual operating load of the computer. They simply indicate the maximum upper threshold. An 800W PSU doesn’t draw 800W every second it’s running – that’s the maximum load it can safely deliver.
To make things even more complicated, computers do not have a steady state when it comes to power consumption. If you have a space heater with low, medium, and high settings of 300, 500, and 800 watts, then you know exactly how much energy is being used at each setting level.
However, there is a whole curve to the power consumption of a computer beyond something as simple as high/low. This curve includes everything from the small amount of power a computer needs to stay in sleep mode, to the modest amount of power it uses for simple everyday tasks like browsing the web and reading email, to the higher amount of power required. for running a high-end GPU while playing a demanding game.
You can’t simply look at the power label and calculate anything from that, other than calculating the absolute maximum amount of power the device can consume.
Use a tool to measure the actual power consumption
Instead of guessing based on the label, you need to actually measure. For accurate measurement, you need a tool that reports the consumption of your computer and peripherals in watts. If you have a UPS with an external display that shows the current load (or has software that allows you to check load statistics via USB uplink), you can use it.
We’d consider a UPS to be a key piece of hardware for everything from your desktop computer to your router – so if you don’t have one now is a great time to get one.
If you don’t have a UPS (or your model doesn’t list power consumption), you can also use a separate power meter like the Kill A Watt meter. We love the Kill A Watt meter and you’ll see us use it a lot, like when we show you how to measure your power usage or answer questions like how much does it cost to charge a battery.
You simply plug the Kill A Watt into the wall, plug your computer’s extension cord into the device (so you can measure both your computer and peripherals), and then check the reading. Easy peasy.
If you use actual measurements, you will quickly find that the power rating of the source does not match the actual power consumption, by a large margin.
Here’s a real-world example: I monitored my desktop computer’s power consumption with both the meter built into the UPS and the Kill A Watt meter to double-check that the UPS reading was accurate.
The PSU in this machine is rated at 750W. But when powered on and idle (or doing very basic tasks like writing this article or reading news) it draws around 270W. Playing relatively light games pushed it into the 300W range .
Under load, whether playing more demanding games or running a stress-test-type benchmark application like 3DMark, which puts a strain on the CPU and GPU, the power consumption rises to around 490W. Despite a few moments that flickered slightly above 500W, the computer in at no point did it even come close to reaching the 750W PSU rating.
Of course, this is just an example, and your setup may have more or less power consumers than mine – which is exactly why you need to measure it to get to the bottom of it.
What to do with this information
Unfortunately, we can’t tell you “OK, so your computer adds 500 watts of power to your room, so it raises the room temperature by 5 degrees Fahrenheit in 1 hour,” or anything like that.
There are simply too many variables at play. Maybe your home is a super-insulated concrete structure with triple-paned windows and an R-value on par with a YETI cooler. Or maybe you live in an old farmhouse with non-existent insulation, constant drafts and single-paned windows.
The season also plays a role. When the sun beats down on your home in the summer, the extra heat radiating from your gaming PC can make an otherwise tolerable room feel unbearable. But in winter it can feel quite cozy instead.
So even if that 500W of power (or whatever it is for your setup) enters the space regardless, because all the electricity eventually becomes waste heat, what that waste heat means for your comfort level and room temperature is quite variable. If you want to see the real Fahrenheit change right before your eyes, put a table thermometer in the room – this model is great for both quick information and tracking data with your phone.
But overall, whether you put the thermometer on a table next to gaming or not, you’ll have to judge how much power you’ll use (and the resulting heat) you’re willing to tolerate based on your computer setup, your home setup, and what cooling options you have available. .
Additionally, you may want to consider shifting usage based on your needs and the weather. For example, if you’re really doing some serious need-my-GPU gaming, you might need to power up your desktop to get the experience you want.
Answering emails or just doing light office work? Maybe turn on the laptop instead and reduce the thermal energy pumped into the room from 300W to 50W or less. A lot of “light” games also work well on a laptop, so you don’t always have to turn on a desktop device to play.
Just messing around on Reddit or reading the news? Maybe skip your desktop or laptop altogether and do these activities on your phone or tablet. In that moment, you’ve reduced your energy consumption from hundreds of watts to just a few watts – and your living space has been significantly cooler in the process.
But hey, if you don’t want to give up all those hours of gaming (nor do you want to heat up your home and sweat while doing it), you can always use the window air conditioner in your game room of choice. both stay comfortable and extract the extra heat your gaming rig brings.