ᐅ Air-to-Water Heat Pump: Current Consumption and Data

guckuck2 schrieb:

The heat comes from solar gains. Our heat pump has settled itself, as it now operates based on indoor temperature control.

Out of curiosity: If the solar energy is not sufficient to maintain the room temperature and your indoor temperature monitoring signals that the heat pump should start again, approximately how long does it take for the underfloor heating system? to bring the rooms back to the desired temperature? We don’t have a heat pump ourselves yet, but once we build a new house, an air-to-water heat pump will be installed as well. However, I keep reading about lead times of around 24 hours before newly set temperature values on the heat pump / turning on the heat pump have any effect on the rooms?

tomtom79 schrieb:

And now please measure that every 2 minutes after the heating is turned off; this way you'll find heating circuits that return warm water to the heat pump too quickly.

I have an old project idea because these longer measurement series are quite tedious. There are small modules with microcontrollers available for just a few euros (e.g., Wi-Fi capable ESP32 variants) that come with a 18650 battery. Paired with a temperature sensor (which can be precise enough and any offsets can be corrected manually), you could attach these devices as needed and let them run. Currently, I have something similar—a 0.002 kW accurate power meter (under €10)—which transmits the data to a small web server running on a laptop.

Schneemann90 schrieb:

Just out of curiosity: If the solar energy isn’t enough to keep the rooms warm and your indoor temperature monitoring indicates that the heat pump should start again, approximately how long does it take for the underfloor heating(?) to bring the rooms back up to temperature?

The system is controlled by the outside temperature and the return flow temperature, meaning the heating is on as long as the outside temperature is below a certain level.
If the return flow temperature drops below a set value, heating will resume.
Because underfloor heating is slow to react, it also cools down more slowly.
Therefore, the issue of rooms becoming too cold like that does not occur.

We haven’t had a single day of sun in the past two weeks, so there have been no solar gains. If we didn’t heat for a few hours each day, the indoor temperature would be around 18°C (64°F). That is no longer comfortable and not feasible.

Bookstar schrieb:

We didn’t have a single sunny day in the last two weeks, so no solar energy gains at all. If we didn’t heat for a few hours every day, the indoor temperature would be around 18°C (64°F). That’s no longer comfortable and not acceptable.

How much photovoltaic output do you still get during cloudy weather? I’ve seen between 0.5 and 2 kW here.

Since I just saw the thread, I'll share some data from our system from April this year. The air-to-water heat pump is a Tecalor THZ504.
We have 4.55 kWp (kilowatt peak) on the roof. 🙂