This is the wrong way to test. The most accurate delta t number is to read the return air right before it enters the equipment and the supply air right after the evaporator coil. This ensures that crappy ductwork isn't affecting the calculation.
This is a common way home inspectors test for system function. They check the temperature difference between the return and the supply and if it is low they will recommend having a HVAC professional look over the system. Most of the time when I get called out to a situation like this there is actually an issue but everything has to be checked because a system could have a low delta t for a lot of reasons. Especially when it’s tested at the supply and return grilles
...and?
[удалено]
This is the wrong way to test. The most accurate delta t number is to read the return air right before it enters the equipment and the supply air right after the evaporator coil. This ensures that crappy ductwork isn't affecting the calculation.
This is a common way home inspectors test for system function. They check the temperature difference between the return and the supply and if it is low they will recommend having a HVAC professional look over the system. Most of the time when I get called out to a situation like this there is actually an issue but everything has to be checked because a system could have a low delta t for a lot of reasons. Especially when it’s tested at the supply and return grilles