ᐅ Comparison of Groundwater, Ground Source, and Air Source Heat Pumps

Created on: 17 Apr 2021 15:38

Hello everyone,
I am planning a new build (two-story single-family house, approx. 140 m² (1507 sq ft) of living space) and definitely want to use a heat pump for heating. This will be combined with a photovoltaic system and a storage battery. I do not want cooling in the house; I only need the heat pump for heating and hot water. The house will not have a mechanical ventilation system. I have received many different opinions from various experts regarding the heat pump, so I have not reached a clear conclusion yet. Maybe you can help me get a better idea?

Here is a rough summary of the pros and cons I have gathered:

Water-to-Water Heat Pump

Highest energy yield and efficiency
High initial costs due to groundwater drilling
Costs are difficult to estimate in advance; depend on groundwater level and soil conditions

Air-to-Water Heat Pump (recommended by the construction manager)

Moderate costs
Low space requirements
Supposedly sufficient for the house (I am not sure about this)
The fan is audible (although relatively quiet), which could potentially disturb neighbors or myself

Ground Source (Brine-to-Water) Heat Pump

Longest lifespan (possibly irrelevant, since after 10–20 years newer technology may be worthwhile anyway)
Lower initial costs
High space requirement for ground collectors (not an issue; the garden is large enough)

Based on my non-expert assessment, I would choose the water-to-water heat pump and accept the additional cost of about €10,000. Are there any arguments I might have overlooked? What are the long-term experiences regarding maintenance work, repair, and upkeep costs?

Thanks in advance!

Bookstar19 Apr 2021 09:55

#19

Strahleman schrieb:

Why should a principle/technology that has been used for decades in HVAC (air conditioning) suddenly be considered unreliable?

Serious question? Because there are savings wherever possible. In the past, washing machines lasted 30 years, nowadays 5 years is common and 10 years is exceptional. Heat pumps are similar—pressure switches, compressors, and controls exposed to outdoor conditions. Gas systems don’t have these issues.

Even manufacturers state that heat pumps last on average only 10 to 15 years. Gas heating systems generally last around 25 years. Major repairs excluded.

Gas boiler investment about 3,000 (currency), and heat pump rather 10,000 (currency).

But I don’t think a factual discussion is possible here, considering what the other user wrote.

nordanney19 Apr 2021 10:03

#20

Bookstar schrieb:

Washing machines used to last 30 years; nowadays, 5 years is considered good and 10 years is excellent.

Does this mean, since you prefer gas over a heat pump, that you’re basically washing clothes by hand these days because washing machines are just unreliable and always breaking down?

You’re hopeless 😀

pagoni202019 Apr 2021 10:24

#21

I think @Bookstar is mainly trying to emphasize that a heat pump is not always the perfect solution for everyone. You, @nordanney, are aware of this and are deeply knowledgeable in various topics, but in my opinion, it doesn’t hurt some younger, less experienced homeowners to approach the heating topic openly and from all angles, rather than just following so-called "standards" as if there were no alternatives. That’s exactly the impression I sometimes get, even though many people are building for the first time and have little or no personal experience with it.

Gas heating can definitely be viewed critically from many perspectives, yet it is generally reliable and cost-effective. Additionally, almost every heating professional is well-versed in it.

Depending on the type, one can be just as satisfied with one system as with another; every homeowner should first understand the concept of flow temperature and then figure out in detail what works best for them.

Bookstar19 Apr 2021 10:35

#22

nordanney schrieb:

So does that mean, since you prefer gas over a heat pump, that you still wash clothes by hand these days because washing machines are just unreliable and always break down?

You are hopeless 😀

No, if I can still get a washing machine with a 30-year lifespan and all the advantages of modern appliances, I would rather choose that. 🙂

Gas is currently cheaper to operate as well. What the future holds is anyone’s guess.

nordanney19 Apr 2021 10:40

#23

Bookstar schrieb:

Gas is currently cheaper to use.

But that is a general statement that doesn’t hold true in all cases.

I could also say: driving with premium gasoline is currently cheaper to use.
That statement is even correct if I compare a small compact car to a large diesel SUV.

However, a properly designed heat pump system with appropriate heating planning does not cost more to operate than a gas heating system.

Please provide nuanced contributions when discussing heating choices. Generalizations are not helpful to anyone here. Thank you.

Strahleman19 Apr 2021 10:46

#24

Bookstar schrieb:

In the past, washing machines lasted 30 years; nowadays, if one lasts 5 years it’s good, and 10 years is outstanding.

Everything used to be better, and generally, I am completely against the throwaway culture and “stinginess is cool” mentality. That leads to a lot of electronic waste, and such generalized statements can be applied to anything. By that logic, you shouldn’t install controlled residential ventilation systems or KNX smart home systems either, because everything is somehow produced cheaply. Why not drive a Trabant if the Daimler EQS is full of electronics that are much more prone to failure?

pagoni2020 schrieb:

I think @Bookstar wants to emphasize that heat pumps are not always the ultimate solution for everyone.

I don’t think anyone here is idolizing heat pumps or promoting them as a cure-all. If you don’t want cooling, want an affordable heating medium, and already have a gas line at your house, you can certainly choose gas. But even in cold regions, I wouldn’t want to install an air-to-water heat pump.

ᐅ Comparison of Groundwater, Ground Source, and Air Source Heat Pumps

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