Two thousand companies, representing 30 countries, and 50,000 visitors descended on the International Air-Conditioning, Heating and Refrigeration Expo (AHR) in Chicago this week to hawk, ogle, and pitch their wares.

The AHR Expo is billed as the largest and most comprehensive HVAC&R event in the world. Attendees — contractors, engineers, facility managers, OEMs, and just about anyone in the HVAC&R industries — come for educational sessions, workshops, seminars, and product demos. What the Consumer Electronics Show in Las Vegas is for tech nerds, the AHR is for HVAC pros.

Today is the final day of this year’s show, but already a clear theme has emerged: smart, energy-efficient appliances and technologies. Here’s a rundown of some of the highlights thus far:

LG Bringing Greener HVAC Products to Market

Electronics giant Lucky Goldstar (LG) announced new energy-efficient products aimed at growing its HVAC business in the U.S. Among them are enhancements to its VRF and Duct Free Systems (DFS) lines, and new high Seasonal Energy Efficiency Rated (SEER) models for residential and light-commercial applications.

Ecobee Unveils ‘Smart Si’ Wi-Fi Thermostat

Ecobee presented its new Smart Si thermostat on Tuesday. It’s designed for the residential market and offers remote connectivity via Wi-Fi, making it accessible through any Internet-connected device, and boasts a new high-resolution color display, an intuitive user interface, sleek buttons and live weather reports.

Tecogen Lowering Emissions Across Entire Line

Massachusetts-based power generation technology company Tecogen announced that its newly developed, ultra-low emissions technology will now be available across its full product line of natural gas engine-driven heating and cooling systems. The company says its natural gas-powered products’ emissions are on par with those of fuel cells. The lower emissions technology was created with funding from the California Energy Commission and Southern California Gas Company.