Each year, EcoHome publishes information on hundreds of green building products, from PV panels to Energy Star-rated appliances to resource-friendly flooring. A great way for the editors to track reader preferences is to follow which products from the print issue received the most requests for information via “circle numbers” found at the end of each product caption.

Garnering the most interest in 2009 was Kichler Lighting’s Design Pro Disc, an LED unit that earned an Editors’ Choice award for its flexible installation and compact design. Like last year’s list, which was dominated by solar products, this year saw a strong category interest—this time in tankless water heaters. But there was also much diversity, with a range of product types—including permeable pavers, metal roofing, and appliances—capturing attention.

In case you missed them the first time around, here are the Top 20 products EcoHome readers wanted to know more about in 2009.