Emerging technologies represent the newest segment of products with the potential to reduce energy consumption. Periodic reviews of these technologies enables concentration on developing the strongest contenders. This analysis, the fourth of its kind, highlights 15 of the most promising heating, ventilating and air conditioning (HVAC) emerging technologies. Full adoption of these technologies would reduce projected US energy consumption by 0.5% - 1% per year. One important finding of this study is that the "well" of emerging technologies and practices has not been drawn down; it continues to yield many promising measures with high energy savings potential.

The technologies covered include:

• Advanced Rooftop Packaged Air Conditioners
• Advanced "Gas Pack" Rooftop Packaged Air Conditioner 
• Commercial Energy Recovery Ventilation Systems 
• Residential Hot-Dry Air Conditioners 
• Smart Premium (Robust) Residential Air Conditioners 
• Advanced Northern Heat Pumps 
• Commercial Ground-Source Heat Pumps 
• Residential Ductwork Optimization 
• Active Chilled Beam Cooling 
• Advanced Modulating HVAC Compressor 
• Automated Fault Detection and Diagnostics for Rooftop Units 
• Liquid Desiccant Air Conditioner  
• Residential Boiler Controls 
• Dehumidification Enhancements for Air Conditioners in Hot-Humid Climates 
• Air-Side Economizer Control Strategies