ᐅ Air-to-Water Heat Pump – With or Without a Buffer Tank?

netuser schrieb:

I still need to understand how you manage 1.5 kWh even with the larger storage 🙂

Why would you expect a larger storage tank to cause higher consumption?
It can be operated at a lower temperature and needs to be refilled less often.

Just to clarify again, we have drifted from the "hydraulic accumulator" to the hot water storage tank. 😉

netuser schrieb:

I still need to understand how you achieve the 1.5 kWh even with the larger storage 🙂

You’ll have to ask my Jeisha. For hot water production, it draws just over 1 kW (1.0–1.3). It takes 20–30 minutes for temperature maintenance every 1.5 days, longer if hot water is used.

RotorMotor schrieb:

But just to clarify once more that we drifted from the "hydraulic buffer tank" to the hot water tank. 😉

Yep, let’s get back to the original question.
==> Buffer tank unnecessary if only heat pump (and photovoltaic) is present

Since we are currently working on the topic of photovoltaics as well.
We have a 300l (80 gallons) buffer tank. With two small children, a mom who likes to sit in hot water every other day, and a dad who sometimes showers twice a day... yes, 300l (80 gallons) runs out quickly :p
If you use a larger tank, you can set the temperature a bit lower because you can draw from the warm water for longer.
The trick with the photovoltaic system is to make the heat pump smart enough to recognize when the sun is shining and increase the temperature accordingly. In the evening, heating is then switched off. So, you draw from the water heated during the day, which slowly cools down to the usual temperature. This way, you maximize the use of the photovoltaic system on sunny days. However, you can only take advantage of this if you have a buffer tank. Without one, it barely benefits you at all.

Evolith schrieb:

You can only take advantage of this if you have a buffer tank. Without one, it actually doesn’t help you much.

That’s why I had a large buffer tank installed. It’s a hidden gem called a screed. Approximately 7 tons. You can store an enormous amount of energy in it and don’t need a small water buffer tank.

Benutzer200 schrieb:

That’s why I had a large buffer tank installed. It’s a bit of an insider tip and is called a screed. Around 7 metric tons (7.7 US tons). You can store an enormous amount of energy in it and then you don’t need a small water buffer tank.

@Benutzer200, maybe it’s better if you just stay quiet when other users are making points? You seem to claim expertise in every field... sometimes less is more.

Hausbau 55 schrieb:

@Benutzer200, maybe it’s better if you just stay silent when other users are making points? You seem to have expertise in every field... sometimes less is more.

Maybe not, because poor arguments shouldn’t be spread here.

And the argument to use a small buffer tank heated by the photovoltaic system (what temperature are we talking about for a buffer tank? Max. 60°C (140°F)? And what size — roughly 50 liters (13 gallons) of storage per kW of heating capacity, so about 200 liters (53 gallons) for a single-family house) to avoid heating at night is simply weak. It’s better to heat the screed a bit more so that this large thermal mass can steadily release its heat overnight — much more effective compared to the small buffer tank.

Buffer tank, not domestic hot water tank.

Oh, and @Hausbau 55: now I would like to hear your arguments.