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

Hello Michael,

one more tip: Just call the info hotlines of various air-to-water heat pump manufacturers next week and discuss it with them. The experts there surely have an idea whether air-to-water heat pump + flat radiators works and respectively where the limitations lie and how severe the limitations are.

Regarding your arguments about gas (tank): fully agree. My father has such a tank in the garden. There are high costs involved, overall not a good solution.

Off-topic: I had to laugh about the Spruce mopeds, the term. Well. So far I only have one spruce moped. Spruce-mopeding is fun.
Yes, my wood stove has a large glass surface (and even a baking compartment, which I finally have to try out).
The stove is rated at 3.3 kW - 7 kW, maximum 9 kW. In other words: It is actually too big for the house. Because I don’t operate it at partial load. For the reasons mentioned.

However – the stove has a soapstone casing and therefore some heat storage, every now and then it gets 2-3 BK briquettes, keeping warm for hours. You can manage that.

Best regards Thorsten

Addition, I just read a little more because I was interested.

There are "low-temperature radiators." You should google that. Various manufacturers.

The systems I have seen also operate below 40 degrees flow temperature but have small fans (in the watt range) and a control unit (meaning a socket on the radiator is required).

However, these radiators are anything but inexpensive (>> 500 euros each).

Furthermore, I saw an air-to-water heat pump from a well-known manufacturer in Hesse that was specially specified for flow temperatures over 60 degrees at -10 degrees outside temperature as well as domestic hot water up to 55 degrees. I didn’t look into it in detail; that must affect the seasonal performance factor, but there are solutions. On the manufacturer’s website, there was also a "consultation button" to request more information. Via Google, you can quickly find the system by searching for "Luft-Wasser-Wärmepumpe für hohen Vorlauf."

No way with low-temperature radiators. I already excluded that right at the beginning. Just as a reminder: Heinz von Heiden offers in the discount segment. So just regular 22mm and heat load calculation based on 55° flow temperature. That was also my question from the start. You can forget your soapstone as a heat storage (another post). No offense, but try applying physics. It’s just about the appearance. But I guess I have to follow your tip about the manufacturers – there’s very little experience in this direction. The risk is that they’ll tell me all sorts of things...... Or do you think they’ll say "doesn’t work... no way"?

Regarding the OT: I know about the soapstone, that's why I wrote "some storage heat." It isn't much. But it's sufficient for the house. However, my dream would certainly have been a proper fireplace instead of a wood stove. But you can't have everything in life. The most important thing is health anyway.

I don't believe that the manufacturers say it can't be done.
My knowledge based on this afternoon's search is: It is possible, with the right heat pump for such design conditions.

The question then is: What system does Heinz von Heiden install? The standard air-to-water heat pump won't easily give you 55 degrees flow temperature. If you know the type of system, you can check.
Do you trust the heating load calculation? Is it plausible? If you know the types/sizes of radiators per room, you have the performance curves via the internet and datasheets. And you know the output of the radiators at lower flow temperatures. From that, you can quickly conclude whether and what reserves you have. Heinz von Heiden should clearly specify the demand in watts per room. If they want to: they can do that. That makes things easier for you.

The bathroom is quickly the problem.
I've had that case too. A larger radiator was installed under warranty, the previous one managed no more than 21.5 degrees at 0 degrees outside even with 60 degrees flow.

My neighbor across the street is building with Heinz von Heiden as well, but with underfloor heating and an air-to-water heat pump. So questions wouldn't be very helpful here.

Hi Thorsten,

nice that you reply so promptly. It would be a Siemens Novelan LAD 7. Do I trust the heating load calculation? Rather not, but what would be the alternative?
And on the other hand: Even if you know all the radiators, you can only say whether their design was calculated correctly – but only with regard to the assumed heating load. And whether that is correct... see above.

What kind of experiences does your neighbor have with Heinz von Heiden – just in general?

Regards
michael

Hi Michael,

the Novelan should - quick research - manage a flow temperature up to 62 degrees. Definitely 55. I’ll have to take another look calmly tomorrow. With 55 you already get a good result. So fundamentally the device is not wrong, at least from a very brief glance.

The heat load calculation: Nowadays modern companies mostly do it via computer. If the parameters are entered correctly – then it is very likely accurate. Certain basic values like transmission coefficients and such you should recognize again from prospect data.

The rooms have different requirements, a bathroom x, the living room y and so on.
The result of an – in my opinion – sensible heat load calculation is basically the conclusion: In room xy I need a heat source with a maximum capacity of w watts.
This then refers to a reference, for example a reasonably chosen minimal outside temperature, in our latitudes something between -15 and -20 degrees.

If you now knew your radiators to be installed per room and the required capacity, you can quickly check using the radiator parameters whether the necessary capacity can be achieved at the targeted flow temperature, or which flow temperature would be necessary to reach the calculated capacity.

The heat pump manufacturer will surely tell you what the system’s annual performance factor is over the outside temperature curve and required flow temperatures … they have tables for that.

That’s what I want to get at. And that’s what I would "fixate" Heinz von Heiden on in this case.

The Heinz von Heiden city villa of my almost-neighbor is not finished yet. Visually a dream, the house. Great. Inside and out. If I interpret my neighbor correctly, he would be in a better mood if the construction had gone faster. Overall, other construction projects next door are progressing faster. The man has gotten advice from me several times – I think I would know if something had gone seriously and out of the ordinary wrong. So everything is probably more or less okay there. More or less okay means a good result from my perspective, and that’s something you first have to achieve when building…

But beware: Every construction project is individual. No single opinion is suitable to represent a representative statement. The core and pivotal point is and remains the builder, how he acts and how he holds the reins. And here is my conclusion: With a relaxed style it will always be a disaster… you build…

Best regards
Thorsten