Air Conditioning, Heating & Refrigeration News, Apr. 21, 2014, by Jen Anesi.
http://www.achrnews.com/articles/126434-ervs-gain-traction-in-new-and-old-projects

"The more outside air a building pulls in, the harder the HVAC system will have to work to condition that air. Heat recovery ventilators (HRVs) help mitigate that energy loss by extracting heat from exhaust air and applying it to the incoming fresh air. Similarly, energy recovery ventilators (ERVs) extract both heat and humidity from exhaust air in order to pre-treat fresh air." Article includes a "Product Showcase" of some of the new HRV and ERV products.