The quiet week

The first week of a new heat pump is the week people most often write us with second thoughts. The thermostat reads sixty-eight. The room reads sixty-eight. The body reads, somehow, sixty-three.

We have heard this from enough homeowners now to know it is not actually a problem with the install. It is a problem with calibration. We are going to walk through what is happening, because the explanation is more interesting than the complaint.

What you were used to

A combustion furnace runs in cycles. The cycle is fast, the airflow is hot, and the temperature in the room rises in a small wave around the setpoint. You stop seeing the wave after the first month of living with it. Your body, however, does not stop feeling it. The body uses the bursts of hot air as a signal that the system is taking care of you. The signal is what feels like comfort.

When the bursts of hot air go away, the signal goes away. The temperature is the same. The signal is what is missing.

What happens next

The body learns. Over the course of a week, sometimes two, the calibration shifts. The steady warmth starts to feel correct. The desire to set the thermostat higher, which is what most homeowners reach for in the first three days, fades. The setpoint that felt cold at the start feels exactly right by the end.

This is not a placebo and it is not a quirk of the equipment. The same thing happens with radiant floor heat, with hydronic baseboard, with any source that delivers steady warmth rather than cycling bursts. The first week is the hardest. The second week, the calibration is already most of the way there.

What to do about it

Three things.

Resist the temptation to set the thermostat higher in the first week. If you set it to seventy-two on day two, the body never learns the actual setpoint, and the heat pump runs harder than it needs to for as long as you live with it. The savings on the utility bill come, in part, from the calibration.

Wear a layer. The room is warm. The body is recalibrating. A sweater is the bridge.

Pay attention on day eight. Most people, on day eight, walk into the room and realize they have not thought about the temperature in a day or two. That is the moment the calibration finished. Notice it. The system has done its work.

A week is short. The relationship with the house, in the right direction, is long.