Over the last 20 years, the Energy Star certified homes program has worked with builders to construct more than 1.6 million better, more energy-efficient homes. Tried-and-true strategies like air sealing and increased insulation form the core of our program, but we’re always looking for emerging technologies that will raise the bar on efficiency.

Oftentimes, these emerging technologies provide the same functions using less energy. Other technologies, however, provide brand-new functions using the least amount of energy.

That’s the case with advanced fresh air systems. Not long ago, the only time you intentionally got fresh outdoor air into your home was when you opened a window. Unless you’re dedicated to doing that every day, that’s not a great approach. As a result, more than 15 states and many above-code programs now require fresh air systems in new homes. These systems follow a schedule to automatically turn on a fan that brings outdoor air in to the home.

Five Emerging Technologies to Watch

in this series, Energy Star building scientists identify the top five products that are on track to change residential home building for the better. They are:

LED lighting. Not your father’s efficient lighting, LED lighting is poised to deliver breakthrough efficiency and innovative functionality right out of the box. LED bulbs reduce energy consumption by 70 to 90 percent--and they have impressive staying power--with a lifetime of 20 years.

Smart thermostats. Next-generation smart thermostats will offer more automated management (and higher potential savings) with less complex setup. Just like DVRs rendered VCR players nearly obsolete, I expect we’ll eventually say goodbye to today’s clunky tedious controls.

Variable-speed HVAC systems. Already prevalent in many parts of the world, these systems have the ability to automatically run hotter or colder, ramp the airflow up and down, and manage the temperature independently in different parts of the house, much like your car’s HVAC system. This is in contrast to most systems used in homes today, which are simply on or off. These added features, plus the potential of greater efficiency, will make this a promising technology as costs continue to come down.

TODAY: Advanced fresh air systems. Not long ago, the only time you got fresh outdoor air into your home was when you opened a window. Now advanced fresh air systems are emerging that automatically pump outdoor air into your home while maintaining comfort, using the least possible energy.

NEXT WEEK: Electric heat-pump and condensing gas water heaters. These emerging technologies are making waves by producing hot water using dramatically less energy and offering features like controlling the temperature from your phone. Though they have a higher upfront cost, they can save more than $1,000 over the lifetime of the product.

That’s a big improvement, but just the first step. Advanced fresh air systems are now emerging that do the same while better maintaining comfort, using the least possible energy.

To do this, two small fans are located next to each other. One fan pumps fresh air into the house and the second fan pumps about the same amount of stale air out of the house. As the air streams pass each other, energy is moved from one airstream to the other. For example, if it’s winter and the air inside your house is warm, then this heat gets transferred to the cold incoming air to heat it up. Pumping this heat from one airstream to the other is a lot more energy efficient than generating that heat from scratch. And a lot more comfortable than pumping cold winter air into your home.

Other advanced fresh air systems go even further. They can remove humidity from moist incoming air; adjust airflow to ease installation and improve performance; as well as ventilate more during the most comfortable hours of the day and less during the hottest and coldest hours.

It seems like a no-brainer to give your buyers fresh, comfortable air in their homes. So, why is this just an emerging technology? A few reasons – lack of familiarity among consumers, builders, and trades; historically few products were designed for homes; and the price tag. However, all of these bottlenecks are rapidly changing.

Click here to learn more about the fresh air requirements in the Energy Star homes program, and how you can earn recognition and build better homes with ENERGY STAR.