The Twin-Volume Edition of the Preston's Guide Index to Manufacturer's Specifications has been updated to 2005, now containing one-half million listings of original factory specifications from 240 manufacturers. Listed are: air conditioners and heat pumps 1960-2005, including rooftops up to 10 tons); gas (1965-2005) and oil (1982-2005) residential forced-air furnaces. The Index is organized by brand/manufacturer, type, model numbers, year made, and original factory ratings for capacity and efficiency. The 928-page, three-pound volume is published as two sections, heating and cooling, (within one cover i.e.; Twin-Volume) in a 8 1/4" x 10 3/4" perfect-bound format.

Contractors throughout North America have come to depend on Preston's as their 'replacement bible,' a sales tool that helps them sell more residential and small commercial replacement equipment and systems. Manufacturers such as Trane, Rheem/Ruud, and Lennox use it, as well as associations like ACCA. ESL and AirTime 500 also recommend it to their members. Preston's users are diverse; from HVAC service technicians, to insurance claims representatives, to home inspectors, this guide is relied upon by thousands of professionals nationwide.

Preston's Guide is independently published, and contractors like the unbiased impression they make when carrying it with them on sales calls. They can look up the homeowner's existing HVAC equipment in Preston's, finding the original manufacturer's specifications for capacity, approximate age and efficiency. The efficiency is then compared with a new, replacement unit's efficiency and the fuel costs savings it will provide.

Preston's Guide can help even the least capable salesperson make a credible sales presentation with data that supports a powerful sales message..."Homeowners need to replace aged, low efficiency HVAC equipment." With ever increasing utility costs, that efficiency message continues to help propel replacement sales as the largest segment of the $100 billion HVAC market.

Now in its sixth edition, Preston's Guide is the only product of its type in the world. It is updated every five years, merging new data with the existing data whereupon a completely new edition is generated. What's more, the oldest years are not deleted and the editions keep growing.