ᐅ Air-to-Water Heat Pump: Current Consumption and Data

netuser schrieb:

@Deliverer, you seem to be quite knowledgeable on the subject. Do you have a specific recommendation regarding the price/performance ratio, especially for the mentioned standard modules ≤ 1.7m*1.0m (5.6ft*3.3ft)?
For me, this is the ideal size to cover the roof as efficiently as possible. Currently, I am warming up to the 340W panels from Axitec.
If there are good 400W panels available for a negligible additional cost, that would be interesting.

I'm not deeply specialized in modules, but more and more companies are adopting the 400W class these days. SunPower started it. LG is following. I've also heard about Trina. And then, mid-year, an old German company will re-enter the market. I’d have to check again as I can’t recall the name.

From a price/performance perspective, the 400W panels are not quite worth it yet. You still pay almost double (SunPower) compared to, for example, Q-Cells 350W. So that only makes sense if you really need high power on a small area. For my new systems, I recently chose Solarfabrik 375W modules. They are, at under €200 (about $215), probably in a good sweet spot. If you want to build cheaply (yourself), you can also go for 330W panels (available from almost all manufacturers), which you can often get for around €120 (about $130) each as clearance stock.

Deliverer schrieb:

I just decided on Solarfabrik 375-watt modules for my new systems. They seem to be well positioned around the sweet spot at under 200 euros (about $215).

Thanks!
375-watt modules with the same panel size? Could you please share the exact model name? I’ll have a look when I get the chance...

Deliverer schrieb:

So what exactly is your point again?

Tolentino schrieb:

[...] simply saying “use a heat pump because it’s more environmentally friendly” ignores half of the necessary conditions.

Implicitly, my point was also that you can make the numbers look good or bad as you like.
I don’t know how the ban will be implemented in Austria, but for example, if all gas heating systems had to be replaced at once, this could actually be worse for the environmental balance than letting the gas heaters complete their normal service life. The production of a new heat pump (which wouldn’t really be needed yet) also has a negative impact.

My recommendation, if someone asked me: “What kind of heating system should I choose to be as environmentally conscious as possible, with reasonably manageable costs?”
- “A heat pump will be the best alternative under the following conditions:
- Find an HVAC engineering firm to calculate your heating load based on the desired room temperatures and to design the heating system and hydraulics accordingly.
- Find a heating specialist familiar with heat pumps who is willing to install according to the external plan (from the HVAC firm).
- Perform a hydraulic balancing during the first two heating seasons. Probably by yourself, since no heating specialist will come by for 10 minutes over several consecutive days to do this.
- Choose a 100% renewable electricity tariff and/or install a photovoltaic system that can feed power into the heat pump.”

The first two points are almost more important than the final choice of heating device. With proper design and installation, a gas condensing boiler will also run more efficiently and can later be replaced by a heat pump without problems (requiring as low a supply temperature as possible).

Well summarized. Anyone who still wants to heat economically now will use the gas boiler and then upgrade in 20 years. However, due to the lack of a gas connection, I also have a heat pump.

netuser schrieb:

@Deliverer, you seem to have quite in-depth knowledge on this. Do you have a specific recommendation regarding the price-performance ratio, especially for the standard modules around ≤ 1.7m*1.0m (5.6ft*3.3ft) mentioned?
For me, that size is ideal to cover the roof as efficiently as possible. Currently, I’m leaning towards the 340-watt modules from Axitec.
If there are good 400-watt modules available at a negligible extra cost, that would be interesting.

For me, the price difference for 400-watt modules on about 20 units was around €2,000 (approx. $2,200) compared to the 340-watt ones. I don’t think it paid off even after depreciation. I can also invest the saved €2,000 differently.

Tolentino schrieb:

Look for an MEP engineering office that calculates and designs your heating load based on the desired room temperatures, including the sizing of the heating system and hydraulics.

This is something you should always do and not just leave to the heating contractor. It costs around €150 (about $160).

Tolentino schrieb:

Find an HVAC specialist who is familiar with heat pumps and willing to work with a third-party design (from the MEP office).

They won’t have much left to do because the heating load calculation for the entire building (which is important for sizing the heat pump) and the floor heating layout plan will already be available. This is something every heating contractor should be able to handle.

I would also recommend having step one done even if you install a gas heating system. It’s well worth the investment.