Modding enthusiast Andy Rawson has developed a thermal imaging add-on device for the iPhone that only cost $150 to build. What’s more, he plans to open source the hardware should you want to build one for yourself instead of buying a pre-made unit directly from him. And unlike the countless number of thermal infrared camera apps already in the App Store, this one is actually functional.

Professional thermal imaging cameras start around $2,000 and can easily top out at over $10,000. Rawson created the device to help find air leaks in his 100 year old home after deciding he didn’t want to spend thousands of dollars for a professional camera.

His device uses a 64-zone far-infrared temperature sensor that transmits data to the iPhone through the dock connector. Temps are overlaid onto the phone’s display and are adjustable for different temperature ranges. The display can show the numeric temperature value for every zone or just a single area.

He’s the first to admit the creation isn’t as nice as a high-end unit but it’s still plenty capable for most basic jobs. Software for the iPhone is ready now although Android users will have to wait a bit longer as code for that operating system is still being developed.

No word yet on when Rawson plans to start selling his IR camera but as Popular Photography points out, it’s likely just a matter of time before this shows up for funding on Kickstarter.