Ok. This is more of a safety factor (25f-10f=15f) than I have seen compared to WF Envision. The Envision cutoff is 15f but WF provides operating data down to 20f (20f-15f=5f). Guess all manufactures are different...

So, what freeze protection is recommended for Sylvia with her ClimateMaster Tranquility loop if the cutoff is changed to 10f (and knowing that more methanol can be bad for heat transfer)?  Should protection be 10f, 25f, or something else?

Our protection is 15f with a 15f cutoff.  Should the cutoff and freeze protection always be matched?

What are the soil conditions? Dry sand, silt, clay ect. all have an impact on loop length and design. 500'/ton will be undersized in some situations and locations therefore low loop temps? Also a colder than normal year? If its the first year, loop performance may be lower due to soil not compacted around loop pipes? Change freeze protection as per manufacture guidelines. Wait to see how it performs over time. Adam

Conditions are soil with a lot of clay and it is the first year. Thanks for input! Sylvia

Sylvia,
I think your installer should spend some time here....
If he used the manufacturer's design software it will size loops for you and predict low EWT.
It sounds like you have 2 problems; 1) your expectations are unrealistic (not blaming you, your installer didn't educate you). 2) your installer did not adequately train for the job and will cost you money (running aux. as your heat pump is not antifreeze protected and allowed to run) or comfort.

Everyone has an alpha project and mistakes are made, but your installer doesn't seem to grasp the fundamentals. Ask that manufacturer's instructions be followed to the letter (re loop sizing and antifreeze as well as duct sizing). Educate yourself with the installation instructions provided to ensure that this is done.

Good Luck,
Joe