Could Cloud Computing Servers Double as Home Heaters?

In the midst of this heat wave, it's hard to even remember what winter feels like. But for those inclined to plan ahead (way ahead) for freezing temperatures, Microsoft Research has a pitch for homeowners: Install a computer server where a heater would normally go.

It’s just an idea, but it’s based around the insight that, as the authors of the Microsoft Research paper write, “Physically, a computer server is a metal box that converts electricity into heat.” Servers’ exhaust air comes out at a scorching 104 to 122 degrees Fahrenheit. But that air is not hot enough to convert back into electricity. (The most common type of geothermal plant, for comparison, channels steam that’s more than 360 degrees.) Servers’ exhaust air is, however, “perfect for heating purposes,” the researchers argue. Channeling that excess heat could turn a regular old server into a “data furnace” that keeps homeowners warm in the winter, dries their clothes and heats their shower water.

As a widespread practice, replacing a run-of-the-mill furnace with a data furnace could save a lot of energy. Data centers use loads of electricity, and they’re only going to use more as more people stream and download more movies and music. But at least in the United States heating uses even more energy (6 percent of the national total, according to the Department of Energy) than servers do (3 percent). If servers doubled as heaters, we’d be getting the same services for half the energy cost.

Individual homeowners wouldn’t necessarily benefit from the switch. The Microsoft paper argues, in fact, that they wouldn’t even notice the difference. The companies running data centers, on the other hand, would benefit. According to the researchers’ back-of-the-envelope operations, the overhead cost per unit of running a host of data furnaces is about a fourth of the cost of running a conventional server farm. A big chunk of the savings comes from the convenience of housing the servers in buildings that people are already using: There’s no need for data centers to buy land and put up buildings with the sole purpose of sticking servers in them. They also save on cooling costs, because the heat they’d normally consider waste is going to good use.

The catch here is that few homeowners need heating year-round. The researchers assumed that heating would be useful whenever outside temperatures dropped below about 70 degrees. On warmer days, the heat would simply vent outside. On hot days, when temperatures top 95 degrees, the servers would have to shut down, since they wouldn’t have a cooling system built in. In places like San Francisco, the researchers calculated, the servers would be useful 96 percent of time and would virtually never have to shut down. In places like Dallas, on the other hand, they’d be useful only about half of the time.

But the Microsoft researchers allow that using servers as home heaters might be a stretch. Much more likely, they note, would be that larger buildings, like business complexes or apartment towers, would adopt the idea first.

Photo via the Department of Energy