Air-water heat pump current consumption and data

2021-11-03 08:40:44

How long was your longest circuit again?

Highest pressure loss is calculated at 5043 Pa=50mbar.

What volumetric flow do you need according to the calculation, and what does the pump achieve now?

Calculated volumetric flow is 1065 l/h. However, the pump regulates the volumetric flow dynamically according to parameters unknown to me. The pump shows me 800-1400 l. I have not yet found a menu at Vaillant that allows me to set the pump to constant.

2021-11-03 09:05:43

The ERR should be deactivated and the overcurrent valve closed to the maximum. Only in this way do you ensure that all the heat produced by the heat pump goes exclusively into the underfloor heating.

Regarding legionella protection. This is a very controversial and much-discussed topic.
If you consider a few points, legionella play no role in single-family homes. The most important point is no dead pipe with stagnant water. Consequently, if a circulation is installed, it should be flushed at least once a day, 5 minutes are enough.
Secondly, the hot water storage tank should be adapted to the needs and regularly completely renewed with fresh water. A 600l hot water tank for one person would for example be problematic. For a family, 200-300l pose no problem. Even better is of course a fresh water station.
A legionella cycle only really makes sense if not only the tank is heated to over 60°C, but at the same time this temperature is reached at all points in the system, meaning all hot water outlets must also be opened simultaneously. Otherwise, in case of infestation, you only select heat-resistant lines, and there are also studies about that. If you want to be precise, you actually need significantly more than 60°C in the system.
During my clinical work of over 10 years in a pulmonary department, which also takes care of the internal intensive care unit of the hospital, there was not a single case of legionella pneumonia from residents of a single-family home.

Do you mean that I should only run the hot water circulation and set the hot water to 45°C?
Should I turn off the legionella protection, i.e. heating up to 60°C (with heating rod)?

2021-11-03 10:48:39

Yes, circulation when installed must run. But please not all day, only during peak times in the bathroom. If the circulation runs all day, you have significant heat loss in the storage tank and waste money. In my opinion, the legionella program is not necessary in a single-family house.

2021-11-03 12:34:17

Legionella program is, in my opinion, not necessary in a single-family house.

This statement was also made by our Vaillant service technician, who seemed like an experienced hand to me. He also deactivated the electric heating element during the briefing.

2021-11-04 06:27:32

Highest pressure loss is calculated at 5043 Pa=50mbar. Calculated volume flow is 1065l/h. However, the pump regulates the volume flow dynamically according to parameters unknown to me. At the pump, 800-1400l are displayed to me. I have not found any menu on Vaillant that allows me to set the pump constant.

The thing with the volume flow is indeed like that with Vaillant or some heat pump models... With my air-water heat pump from Vaillant, the pump also cannot be set to a constant volume flow. The only adjustment option is via the residual delivery height, and then in heating mode it always hovers around max. 60-70% power. For my model, that means about 600-750 l/h in heating mode and in hot water production this crappy thing manages about ~ 1200-1350 L/h

2021-11-04 06:43:05

Modulating heat pumps regulate the volume flow to achieve the optimal supply-return temperature difference at the required heating capacity. This is important and correct for efficiency.

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Air-water heat pump current consumption and data

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