No setback for heat pumps.
The more efficient the heat pump, the cooler the tubing.
A better measure is at the supply and return vent.
A 15° differential is very good....on a 50° day that would be normal.
But anywhere from 10 to 20° can be expected, depending on conditions.
It all depends on the unit.
Remember that the units raise the heat of indoor air. If they start at 61° the most they can be expected to put out is around 70° - 75°.
And that may feel cool compared to skin temp.
And the colder it is outside the less effective a heat pump is.
Plus when you set back the thermostat, it takes longer to bring up the heat and then electric elements will kick in to help out. Keeping the thermostat at a constant temperature will minimize that event.
The more efficient the heat pump, the cooler the tubing.
A better measure is at the supply and return vent.
A 15° differential is very good....on a 50° day that would be normal.
But anywhere from 10 to 20° can be expected, depending on conditions.
It all depends on the unit.
Remember that the units raise the heat of indoor air. If they start at 61° the most they can be expected to put out is around 70° - 75°.
And that may feel cool compared to skin temp.
And the colder it is outside the less effective a heat pump is.
Plus when you set back the thermostat, it takes longer to bring up the heat and then electric elements will kick in to help out. Keeping the thermostat at a constant temperature will minimize that event.