Is the furnace big enough? Is the air conditioner near the end of its life? When you need to know the age or capacity, grab Carson Dunlop’s 220-page Technical Reference Guide. This handy field book does a wonderful job of helping determine the size and age of hundreds of heating and cooling systems and water heaters from the model and serial number.
Although the book has been around for years, it was significantly modified in 2010, with over 200 updates and a newer easy-to-read format. Is it simple to find what you are looking for? Absolutely! The layout is alphabetic by manufacturer, so browsing is fast. For the more disciplined inspector, the Table of Contents directs you to the appropriate page for each company.
How does it compare to the Carrier Blue Book or the Preston’s Guide? Because it is laid out with the home inspector in mind, and includes phone numbers and websites for most companies. Another bonus is the data included for components such as burners, transformers, gas valves, pumps, compressors and controls. CDW Engineering, Carson Dunlop’s commercial inspection company, has made sure the book is useful for commercial inspections too.
Other extras include heating and cooling capacity guidelines, combustion air requirements, conversion factors and formulas, and typical life expectancies. The tabular form helps you find what you need and get back to your inspection or report writing quickly.
Appendix A provides cross references to help find those tricky companies that have changed names or been bought by others, for example.
What does it cost? Not much. The retail price is $79, but ASHI members can get it for $69 at ASHI’s Online Marketplace.