HvH combines air heat pump with panel radiators - temperature values?

Maybe we are also talking about different systems. The normal 22s (double-wall radiators) actually release most of their energy through air circulation. Keyword chimney effect. It may look different with the real flat radiators (single plate). I am not informed about that. What is certain, however, is that the low feed temperature causes a higher radiant share.

That cannot be. The radiant power is proportional to the third power of the temperature. No engineer can override that with a simple plate.

Hi Saruss

I think I understood it
but can you also briefly explain it without me having to google?



Olli

This means that the heat output by radiation increases disproportionately with temperature; the whole thing can be slightly controlled, for example, by material and color choice, but not "overridden." Conversely, the radiation output decreases quite significantly with falling temperature (and the frequency spectrum changes, which can also be important; especially when the pleasant heat radiation then makes up a smaller proportion). A radiator can therefore only have a high radiation share at low flow temperature if the convection output is ESPECIALLY small; in other words, the radiator has overall low heat output. In a well-insulated house, however, this can already be sufficient with heating loads of 300 watts for an average room during biting cold outside.

In the manual for the mentioned heat pump, you can find after 5 seconds on page 23 the important data, a COP of about 2-2.5 can be read at 0 degrees source temperature and 55° flow temperature.

According to my source, it is page 21. There I read a COP of 2.75 at 0° and 50 degrees flow temperature. If I operate with 45°, there should still be COP values around 2.5 even at -10°. What source do you have? I have the 48-page manual as a PDF file. Strange, though, that nowhere in mine is there any mention of return temperatures. That is significant - or does EN 14511 assume a standardized parameter.

Okay, I simply took them from the manufacturer's website, novelan.com. On page 23 of the 48-page manual are the performance diagrams. However, the curves drop sharply with increasing flow temperature, so your numbers are correct, but is a 45°C flow temperature really sufficient for radiators at -10°C? Also, the total output decreases significantly at those temperatures, so you quickly need an electric heater. The temperature difference at the values is 5K, is that caused by the radiators/the circulation pump, etc.? The heat pump itself is quite good, but I see the problem that if it delivers enough output below 0 degrees, it will have to cycle a lot at 8-15 degrees, meaning it has too much power and might run inefficiently.