How to plan heating with a heat pump in new construction?

The claim that electricity will not become cheaper is a bold thesis that is heard more and more often, but is not supported by anything at all.

Well, the plan is that in the next 1-2 decades everything that we currently run on fossil fuels will be electrified. At the same time, the existing fossil power supply is to be replaced as completely as possible. Sun and wind don’t send a bill, but the systems for them cost money. You always tell us how photovoltaic systems can’t be profitable at 4% interest. Then there are storage solutions at the grid level (significantly more expensive than a pile of coal lying next to the power plant) and a lot of new high- and extra-high-voltage lines, also to be financed at 4%. By the way, the equity used for this may be financed at 7% at the expense of your grid fees. So... nothing is proven and soon we will all get electricity in the green wonderland at 10c/kWh

The claim that electricity is not getting cheaper is a bold thesis that you hear more and more often, but it is not supported by anything at all.

If the heating becomes 10, 15, 20,000 EUR more expensive due to partly absurd specifications like a max flow temperature of 25°C. When do you save that back again? You have to advance the money first...

And you prove once again that you shouldn’t say anything about certain topics.

You reach a flow temperature of 25 with every current heat pump. And the additional costs that arise are the 200 meters of extra tubing and the craftsman who installs it, roughly 2, maybe 3 hours...

Far from 10,000 euros.

By the way, the reason electricity prices rise lies solely in the fact that the currently burned resources are finite and we still have to buy them abroad. The only positive thing about that is that we have to think hard again and maybe in a few years will make a groundbreaking invention.

Laying distance nowhere greater than 10cm; in the bathroom, walls are mandatory; maximum cable length 80m

A smaller laying distance is necessary so that the heating operates with a lower flow temperature. Did I understand that correctly?

Hello,

A smaller spacing is necessary so that the heating system operates with a lower flow temperature. Have I understood that correctly?

(Almost) correct. With a smaller spacing, your heating system CAN run at a lower flow temperature. With less spacing, you basically have more hose lengths (= "radiators"). This means you can manage with less temperature difference.

Where the optimum lies is very much debated. Here in the forum, the mantra has always been a max of 30°C flow temperature, but now I see that 25°C is the new fetish. In principle, it is true that with a lower flow temperature you have a higher efficiency of the heat pump. However, you have significantly more pipe lengths and thus flow resistances that your pump has to overcome. Additionally, you possibly have significantly higher investments due to more heating circuits, etc.

Best regards,

Andreas

Understood. And what is the deal with this buffer tank and why is it counterproductive with a heat pump?

The buffer tank was previously needed with non-modulating heat pumps to prevent constant cycling. Then the heat pump would raise the water temperature to a higher level than actually needed, and only as much water as necessary was drawn from the buffer to reach the target flow temperature. If the heat pump can modulate, this is generally no longer necessary for underfloor heating. However, since the Building Energy Act unfortunately requires individual room controllers for heating in every room, many manufacturers specify a small buffer so that the heat pump does not run empty during a general heating demand (e.g., actual temperature drops below target temperature) but with completely closed ERR throughout the house, which would cause the compressor to have frequent micro-cycles and thus not be sufficiently lubricated (minimum runtime 5 minutes or as required). Solution: Simply keep ERR always open or ideally omit it altogether (exemption necessary).