Conglomerate Honeywell, which develops thermostats, has filed a patent infringement lawsuit against Nest Labs, the developer of the innovative smart thermostat. The lawsuit, which was filed United States District Court for the District of Minnesota, alleges infringement of seven Honeywell patents related to its thermostat technology.

As we’ve reported in the past, Nest, which was founded by the godfather of the iPod, not only provides an intelligent thermostat for your home but also saves energy as well. For example, the technology will analyze the thermal decay of a house to determine how long it takes for heat to dissipate. An “Auto-Away” feature uses far-field motion detection to assess whether no one is in the house for a few days, perhaps because you’ve gone on vacation. If so, the unit goes into low-energy mode.

The Nest thermostat also tracks your manual heating adjustments. For example, it can learn that you turn off the heat when you leave for work in the morning and turn it back on when you return in the evening, and then start to automatically make these changes for you. You can see a demo here.

Honeywell claims the infringed patents relate to “simplified methods for operating and programming a thermostat including the use of natural language, user interfaces that facilitate programming and energy savings, a thermostat’s inner design, an electric circuit used to divert power from the user’s home electrical system to provide power to a thermostat, and controlling a thermostat with information stored in a remote location.”

The lawsuit actually names both Nest Labs and Best Buy, which sells the Nest Labs thermostat. Honeywell not only wants to prevent Nest from the continued use of its patented technology but also seeks to recover damages caused by the infringement.

Interestingly, Honeywell recently told GigaOm that it killed off its smarter, learning thermostats years ago, instead focusing on ‘adding intelligence to digital and connected thermostats.”

We’ve contacted Nest for comment on the suit. We’ll update when we hear back from the company.

UPDATE: Nest issued this statement to us: We have not yet reviewed the actual filing, which we learned about this morning through Honeywell’s press release. We will provide comment once we’ve had the opportunity to review it.