Ask an office manager why the desks went thin and the answer is rarely speed. It is the electricity bill, the silent room, and a UPS that suddenly lasts through the whole power cut. Here are the numbers - stated as honest ranges, because models differ.
A desktop PC is a small room heater that also computes. A thin client moves the computing to the server room and leaves the desk with a fraction of the draw. The ranges below are typical figures across common models, not a promise for any single box - your model's adapter label always has the final word.
✓ Ranges, not guarantees - the adapter rating printed on your model's power brick is its ceiling.
👆 Typical ranges across common models. Measure your exact unit if the number will drive a UPS or bill decision.
Most thin clients work in the single digits to about fifteen watts. Ordinary desktops idle and work far above that, and older desktops with spinning disks and hungry power supplies sit at the top of the range. The honest way to check any specific model: read the adapter's output rating - the box can never draw more than its brick can give, and usually draws well under it.
Most thin clients have no fan and no spinning disk. There is nothing to clog with dust, nothing to whine at 4 PM, and almost nothing mechanical to fail. The metal case doubles as the heatsink, so warm-to-touch is normal and expected. In return, give the box open air - a fanless unit buried in a closed drawer or under paper piles will overheat exactly like anything else that cannot breathe.
UPS runtime is simple division: battery capacity shared among everything plugged in. Replace ten desktops with ten thin clients and the same UPS that lasted twenty minutes can carry the desks - and, importantly, the one server everything depends on - through a much longer cut. In offices with daily power cuts, this is often the reason thin clients win the argument, ahead of the electricity bill.
Example only, with its assumptions in the open: 10 desks, 9 working hours a day, 26 days a month. Desktops at an assumed 100 W average use about 234 units (kWh) a month; thin clients at an assumed 10 W use about 23. The gap - roughly 200 units a month - is worth real money at commercial tariffs, before counting the air-conditioning load that desktop heat adds. Your tariff and your models will move the figure; the order of magnitude will not.
Fanless and cool-running is not the same as indestructible. A thin client in a hot, dusty, non-air-conditioned godown or factory corner lives a harder life than the same box in an office - heat ages electronics, and dust insulates. Mount it with airflow, keep it off the floor, and in genuinely hot environments expect a shorter life than the brochure's office numbers.
See the four models in the video - their size, their adapters and their working draw are part of why the best and worst separate the way they do.
▶️ Watch Full VideoAt a typical 10 W draw for 9 hours a day, about 2.7 units (kWh) a month - roughly a tenth of a working desktop. Your model's adapter label shows its maximum; real draw is usually well below it.
Warm is normal - the case is the heatsink. Hot enough to shut down means blocked vents, a very dusty or hot environment, or a failing unit. Give it open air and it should run for years.
Yes - this is one of their biggest practical wins. Ten thin desks plus the server on one mid-size UPS is realistic, where ten desktops would demand a far larger and costlier unit.