As stated at the top of the Help page for the Integrated Library,
"As of REM version 12.9, we recommend NOT using this library until it has been revised and updated. The ASHRAE Standard on which it was based has been substantially changed, and the CAef and CAafue parameters on which the library depends are no longer available."
This library has been outdated for quite a while; indeed, the version of the Standard on which it was based was quite short-lived, due to some fundamental problems in the CAef and CAafue approach.
Typically integrated equipment is a combination of a heating source (boiler or water heater) which serves both space and water heating. It is our recommendation to seperate the two components in the heating and water heating libraries based on their specifications. The REM help gives advice on the efficiencies of integrated equipment.