Can you use data centers to heat cold rooms? Lessons from a cryptomining spa

You can heat a spa with a server farm. But you might not want to.

Since 2022, New York startup Bathhouse has used waste heat from its Bitcoin-mining operations to warm saunas, steam rooms and pools. The company just opened an outpost in Philly, and anyone is welcome, with day passes ranging from $30 to $75.

The no-phone zone smells like incense and chlorine, with background music reminiscent of drum-circle meditation. No common cryptomining complaints like buzzing noise pollution or industrial development in sight.

“Our Bitcoin mine is just a different type of pool heater,” reads a Bathhouse FAQ. The company says it uses electricity it would have bought to heat its pools anyway.

But it doesn’t necessarily save money. 

In 2024, two years into the project, Bathhouse coowner Jason Goodman told Time Magazine that the bills at its two locations were still roughly the same as before introducing the mining heat. The payoff, he said, was in a more energy-efficient system and that sitting on the coins will vest. 

What the company hasn’t shared is just how much it spent to get started. We know that as of 2024, it bought 32 ASIC chips to mine at its Manhattan and Brooklyn locations. Then, it spent resources removing fans and converting the hardware to work for the spa use case. Plus a pump, heat exchanger and other equipment.