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What is the real story around heat pumps?

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Someone:

--- Quote from: pcprogrammer on February 24, 2024, 08:24:16 pm ---
--- Quote from: Siwastaja on February 24, 2024, 09:31:32 am ---
--- Quote from: pcprogrammer on February 24, 2024, 09:03:32 am ---The whole idea of these systems to pay for themselves is kind of bullshit. Sure it can reduce on your energy bill, but it will still cost money. Depending on the type of system and the cost to install it can take a long time before any savings start to come.
--- End quote ---
Remember that expensive systems such as quoted for you are a kind of specialty of wealthy societies and wealthy households. Energy solutions are being sold exceeding their true value, because there is market for that and people still buy. My air-to-water heat pump installation was less than 4000EUR all parts included, although I did the install work myself but it would have been less than 1000EUR for work if I just paid for hourly rates for electrician and plumber; and the end result is way better than how a typical 15000EUR complete one size fits all solution would have been.

Typical cost for air-to-water retrofit was around 8000-9000 EUR here but nearly doubled to 14-15000 EUR almost overnight after a 4000EUR subsidy come into place. The market does not reflect actual costs, and any subsidies further twist the market. Enough people are willing to pay outrageous prices when they feel good about it.

In Japan air-to-air heatpump costs something like 500EUR installed so one can easily afford one per each room. They do pay back for themselves, that's literally why they were developed in 1980's in the first place, to save cost of fossil fuels.

--- End quote ---
Even when I would get a cheap monoblock heat pump and do the work myself and spend say the 4000 euro you mentioned yours costed, it would still take a very long time to see a so called "return on investment" or reach a break even point.

What I pay now for my heating is 24m3 of fire wood at 55 euro the m3 is 1320 euro.
On average loss of interest on 4000 euro in a savings account lets say 80 euro. (At the moment we get more then 2% here in France, but it will vary)
Needed heat energy 16500KWh at SCOP 3.5 is ~4714KWh at an average electricity price of 20 euro cents comes to 942,8 euro.

So saving comes down to 1320 - 942,8 - 80 = 297,2 euro per year so comes down to about 13,5 years. At that time it might be needed to buy and install a new heat pump. If not you will have to save up the money you save and it will take another 10 years, with interest on interest, or so to get the initial 4000 euro back in the bank.

This is not taking into account the cost of owner ship like maintenance or replacing defective parts if needed, nor is it taking into account the rise in electricity price that comes round once in a while. The latter would also effect the price of fire wood, so not really needed to adjust for.

And that is why I said that living costs money.

It might be different for others who have much higher heating costs with their current system, but still you will never really get your investment back.

To me there is a distinction between saving money and making money. With PV solar panels it might be a different story when you harvest way more energy than you consume and can actually sell the remainder to the energy company. But then still you have to take cost of owner ship into account.
--- End quote ---
Well you did start this thread on the basis that you had to get something to replace the wood burning, or perhaps you'd like to add labour for someone to come and cut/dry/handle/load the wood for you?  ;) We've seen this before with people claiming they get their wood for "free" so it's not a cost.... in their shallow analysis.

"profit" can be real for heat pumps where someone has an ongoing need for some quantity of thermal heating, even if that is immediately replacing or augmenting an existing fully functional heat source. Of course the number varies wildly around the world. What is more common is your situation where a new heater is needed as an existing unit is absent/expired/unserviceable and the choice is now investing one way or another. Higher upfront investment can produce cheaper lifecycle costs, but as you found it needs careful analysis of the available options as salespeople generally only care about their immediate profit while you have some different (varying from person to person) horizon in mind for the investment. Easiest just to state where you want those analysis to sit as you have and then it's clear to everyone!

nctnico:

--- Quote from: pcprogrammer on February 24, 2024, 08:24:16 pm ---
--- Quote from: Siwastaja on February 24, 2024, 09:31:32 am ---
--- Quote from: pcprogrammer on February 24, 2024, 09:03:32 am ---The whole idea of these systems to pay for themselves is kind of bullshit. Sure it can reduce on your energy bill, but it will still cost money. Depending on the type of system and the cost to install it can take a long time before any savings start to come.

--- End quote ---

Remember that expensive systems such as quoted for you are a kind of specialty of wealthy societies and wealthy households. Energy solutions are being sold exceeding their true value, because there is market for that and people still buy. My air-to-water heat pump installation was less than 4000EUR all parts included, although I did the install work myself but it would have been less than 1000EUR for work if I just paid for hourly rates for electrician and plumber; and the end result is way better than how a typical 15000EUR complete one size fits all solution would have been.

Typical cost for air-to-water retrofit was around 8000-9000 EUR here but nearly doubled to 14-15000 EUR almost overnight after a 4000EUR subsidy come into place. The market does not reflect actual costs, and any subsidies further twist the market. Enough people are willing to pay outrageous prices when they feel good about it.

In Japan air-to-air heatpump costs something like 500EUR installed so one can easily afford one per each room. They do pay back for themselves, that's literally why they were developed in 1980's in the first place, to save cost of fossil fuels.

--- End quote ---

Even when I would get a cheap monoblock heat pump and do the work myself and spend say the 4000 euro you mentioned yours costed, it would still take a very long time to see a so called "return on investment" or reach a break even point.

What I pay now for my heating is 24m3 of fire wood at 55 euro the m3 is 1320 euro.
On average loss of interest on 4000 euro in a savings account lets say 80 euro. (At the moment we get more then 2% here in France, but it will vary)
Needed heat energy 16500KWh at SCOP 3.5 is ~4714KWh at an average electricity price of 20 euro cents comes to 942,8 euro.

--- End quote ---
Just out of interest: Are there any ways you could reduce the amount of heat you need without sacrificing comfort?

pcprogrammer:

--- Quote from: nctnico on February 24, 2024, 09:21:38 pm ---Just out of interest: Are there any ways you could reduce the amount of heat you need without sacrificing comfort?

--- End quote ---

Not really as it is already set reasonably low. I'm thinking about heating up more during the night at a reduced rate, but not sure if the offered pump will supply enough energy to reach the needed temperature rise on the coldest days when profit would be biggest.

That is part of the experiment.


--- Quote ---Well you did start this thread on the basis that you had to get something to replace the wood burning, or perhaps you'd like to add labour for someone to come and cut/dry/handle/load the wood for you?  ;) We've seen this before with people claiming they get their wood for "free" so it's not a cost.... in their shallow analysis.

--- End quote ---

I never claimed the wood to be free, but do still have about 12m3 from one of our own trees. It was a hell of a job to take it down, partly due to my disease, but also because it was a very big oak tree to close to the house. Cutting up all the branches and the trunk took us weeks. Apart from that labor and the petrol for the chainsaw and electricity for the splicer it is "free" wood.  :-DD

The thread was started to find out if sales people are lying about air to water heat pumps having far worse performance then ground to water heat pumps, and what the noise levels are.

And as with everything on the net you have to filter and analyze the given answers to get to the bottom. Conclusion is that the two systems are not far apart and definitely not the factor two that one of the sales people claimed.

Siwastaja:

--- Quote from: pcprogrammer on February 24, 2024, 08:24:16 pm ---This is not taking into account the cost of owner ship like maintenance or replacing defective parts if needed, nor is it taking into account the rise in electricity price that comes round once in a while. The latter would also effect the price of fire wood, so not really needed to adjust for.

--- End quote ---

Yeah. Calculate the cost for maintaining the wood burner and especially the time and effort you need to spend burning wood, and it not only evens out but exceeds that of the heatpump because the monoblock heatpump is nearly maintenance-free. I have had mine running for three years with no maintenance, unless you include the few seconds of my time used to pick a stuck leaf out of the evaporator coil. End-of-life for such heatpumps is typically around 10 - 20 years, maybe 12-15 median. Calculate the savings with a slightly pessimistic 10 years and you won't go too wrong.

In your case, you will again reach optimum with a hybrid system (as you don't have to invest in wood burner): burn wood when COP < 2 or so, and this effectively brings the SCOP of the heatpump up, and thus total energy cost down a bit.

Siwastaja:

--- Quote from: pcprogrammer on February 25, 2024, 07:00:25 am ---I never claimed the wood to be free, but do still have about 12m3 from one of our own trees. It was a hell of a job to take it down

--- End quote ---

Now the question really is, do you want to burn the results of your hard work in one winter, or maybe use it in a hybrid solution for the next 5 winters?

I started renovation of upstairs by just dismantling everything before putting in new materials, and that produced a few m^3 of 2x4" and 1x5" from 1950's, good untreated wood (spruce most likely). My wife spent a lot of time removing all the nails before I cut it to fixed length pieces. So in the same sense, this is also "free" wood, but carries some emotional attachment.

In addition to random sauna use, I have used this wood to heat the house for two winters now and it feels good to use this "waste". If I only heated by wood, it would have been gone in the first winter even before the first seriously cold weeks. During that time, the heatpump on the other hand produced heat with excellent COP and little electricity.


--- Quote from: Someone on February 24, 2024, 09:18:32 pm ---salespeople

--- End quote ---

Salespeople are funny. Expensive turnkey solutions:

What salespeople sell to the customer: theoretical savings of the best case installation +30%, payback in 2 years
How you are billed: Heavily customized solution tailored for your specific needs, with the best-in-class oversized heatpump
What you actually get: underdimensioned, one-size fits all installation, with some unoptimal flaw which wastes half of the savings, payback in 30 years except the pump doesn't last that long.

Then again, if you know something about the market and products and how they are useful, you still don't have to DIY, but you have to manage the project. This way cost is less and end result better than with most turn-key solutions.

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