Homeowner Q: typical cooling differential?

sachmo

When designing a system, what is the typical temperature delta (outside vs. inside) that is regarded as normal if the system is operating normally?



ie: when its 95 outside, and you have the thermostat set at 72 permanently, what would you normally expect the inside to be?



I know its whatever the system was designed for after a heat load calc, but what is the range of "normal" in designs.

Gordy

right design

If it is designed right then 72* is what you would expect.

TonyS

In eastern PA

I design for 20 degrees, otherwise an oversized unit wont run long enough to dehumidify.

With the inverter mini splits you can go more.

Central air with an ECM blower and a humidistat can also be a little larger because the airflow over the coil can be slowed down until the humidistat is satisfied.

I would imagine in areas with low RH the unit is never oversized, just faster.

Techman

another opinion

Since I'm just a repair guy I don't have to be correct.I thought the design TD used to be 20* but now it is recommended to be 15* Lets hear from The Professor or a design engineer.

TonyS

Thats what I heard

15 degrees is what is recomended...that being said, I am sure who recommended that doesn't have to answer the phone and listen to customers complain why they can only cool their house to 80 degrees.