Don’t fall for the 40-50k heat pump trap. Buy a Panasonic Aquarea for half the price (incl. material) and install it yourself.
More details please! Why this model? Any links/guides?
I chose a Panasonic heat pump due to its massive DIY community, particularly in Germany, and a recommendation from a local refrigeration expert. After frustrating experiences with traditional heating companies, who often double the equipment price and can’t answer basic technical questions, I turned to refrigeration professionals instead. Since heat pumps and air conditioners operate on the exact same principles, refrigeration experts actually understand the technology they are installing. You’ll have to coordinate the electrician, someone who can pour concrete/drill holes in walls and a refrigeration expert if you don’t want to do it yourself. (I would not advise to do the work with the company from the following links but would just buy the heat pump and material but nothing more)
7kW https://www.ecoenergy-solutions.ch/pages/warmepumpen-komplett-sets#Komplett-Set-Small
9kW https://www.ecoenergy-solutions.ch/pages/warmepumpen-komplett-sets#Komplett-Set-Medium
16kW https://www.ecoenergy-solutions.ch/pages/warmepumpen-komplett-sets#Komplett-Set-Large
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I assumed the handling of the refrigerant would require a certified installer. Did you go through this process already or are still in the research stage?
Everyone who has water air heat pumps tell me that they mostly run on electricity since the air is very cold a lot of time for actual efficient energy savings and it’s not worth it. They all recommend ground source heat pumps as a more efficient alternative but they are also more expensive. Do you have details about the operating costs for the Panasonic models?
All properties still have functioning air/water heat pumps, but some are over 20 years old, so I had to research and plan what to do if one breaks beyond repair. I then discussed it with my local refrigeration company, who said they were fine with it. They also told me that my 20-year-old heat pumps are easily repairable, as they use basic parts that are still widely available on the spare parts market, and that they would just replace the faulty components.
They were then sold poor-quality heat pumps which lose a lot of efficiency as the air gets colder. The Panasonic models mentioned are T-CAP, which maintain their full heating capacity down to -20°C.
No, but if you know your heating requirements in kW, you can calculate your costs using a COP of between 3 and 4, and then multiply this value by your kWh price, as this is the range in which the Panasonic operates.
Re: regulation, I was thinking of split systems where you’d have to have refrigerant plumbing between internal and external units which is regulated in Switzerland. But if yo use monobloc, you can avoid that as you’re just connecting water pipes, but you have to deal with the issue of potentially frozen pipes.
I have been looking into this quite extensively even almost opened a company in that field (the margins in that business are crazy high)..
We operate a Panasonic Aquera 9kw split since over 10 years without any problems. I planned it myself and had it installed through a german company with support from swiss electricians etc.. Total cost including water was little over 20k CHF. We now have registered the unit with Meier/Tobler which 24hour service we can call if something doesnt work anymore (we didnt need it so far).
Its fairly efficient and quiet (todays model are even better I reckon). A key factor for Water/air heatpumps is the location of the building - height over sea as a key driver for efficiency. Typically the savings for drilling a whole will take a long time to reclaim - if at all. in our case it would save about 400 chf (30%) in energy per year at an extra cost of about 20k for the drilling/plumbing (so about 50 years for break even..). The advantage of water/water systems is the free-cooling feature which can become more important with climate change and increasingly warm summers..
A problem in DYI is warranty, support and particularly getting subsidies. Its hard to unlock usbsidied unless you have a certified installation (FWS, Suisstec). the whole installation must also be WPSM certified to receive full subsidies (asfaik).
If you find the right panasonic partner to have your installation properly put into operation (official commission) to be able to claim warranty later and important for subsidies.
Its still messy and the current system is stacked against DYIers in Switzerland, even if the installation itself becomes increasingly less complex due to fully integrated systems.
Its been a while since I looked into it and things might have improved for DYIers. Happy to learn more..
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this is true. You need a special certification to link these units (“Kälteschein”). Also systems that use more than 3kg of refrigerant (very long connection lines outer and inner system) must be annually checked by an expert (making it a no go for most small installations). Further, since propane (A290) has become the defacto standard for new system - more regulations towards fire/explosion proofing is required which can put additional complexity on DYI installation.
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I don’t think frozen pipes are so much of an issue. Ideally the monoblock device goes 1/2 a metre off an external wall. If it needs to go further away you can typically connect the flow + return lines from below and then bury it. My device going in this summer will use a pre made insulated pipe like this:
https://raleo.de/files/img/11ede40af158244cbe4bb42e99482176/original_size/1093894_REN
Freezing only becomes an issue when the power goes out at the wrong time
I think the real issue for a DIYer is the fact that the heat pump is not like a typically gas or oil boiler. These devices are so simple (sure condensing boilers leverage some thermodynamic gains, but we’re talking +20%) that they simply « make it hot ». A heat pump needs to be designed to fit the system.
If you’re not a fairly technically minded individual who is comfortable with 1st year uni physics unless you get lucky your best case scenario is a shit SCOP (2 instead of 4). Worst case you massively oversize Because you replace your 23kw boiler with a 23kw heat pump and it cycles during low demand periods and the compressor dies after a winter or two. I must emphasize it is rare that you can 1-1 replace a gas or oil boiler with a heat pump. It’s usually a significant system redesign and most likely a full heat load calculation for the house should be done.
I personally was comfortable that I could design a good system, but I opted to have it installed this year by a firm and I’m focussing on other DIY jobs alongside it (plastering popcorn walls in rooms smooth, putting in new window stools and redoing floors). These things are much lower risk (heat pump has 1000-2000 l/h flowing around your house all winter and if something bursts you might be up shit creek with the insurer.
If anyone really wants to go the diy route I’d be happy to send some reading material/youtubes. Mostly in German but there’s some English speaking content from the UK too. But I must add that unless you are already comfortable with basic physics your time would be better invested elsewhere in my opinion
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Given the long cold periods, frozen pipes are an issue. Insulation can slow freezing but can’t stop it. You need to keep the unit running (power cut risks) and put additives in the water loop to reduce freezing temperature as a failsafe (so it can survive, say, -10C) but this reduces heat transfer efficiency. It’s all manageable, but still needs to be dealt with.
Anti-freeze in the loops is a big no no is my understanding. Antifreeze valves are usually specified by manufacturer though. These go typically just before the outside monoblock
I would say the real measure against freezing is the inclusion of a buffer tank (pufferspeicher). This is usually around >20l/kw of heat pump power and ensures enough thermal mass in the system to ensure that freezing isn’t a risk. If the power goes out one could have issues…
a lot of crappy installers will put this in « parallel » which leads to inefficiency Because the flow from the monoblock is allowed to mix with the return and kills your scop.
A competent installer will put it only on the return (with a pressure relieving overpressure loop) OR a « partial decoupling » (what I’m going for) where you can use the buffer as a battery and still get a very high scop.
First of all you have the antifreeze valve which is a mechanical, self-opening brass valves installed outside at the lowest points of your flow and return pipes. They do not require electricity. Inside the valve is a thermostatic element. If the water temperature in the pipes drops to a dangerous level (usually around 3°C), the valve automatically opens and begins to drain the water from the system.
If the outdoor temperature drops to freezing, the heat pump’s internal circulation pump will automatically turn on, even if the house doesn’t currently need heat. Moving water is much harder to freeze than standing water.
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Yes, the freezing risk is only for when there is a power cut. As you say, the unit should keep running to prevent freezing otherwise.
I thought adding glycol was common in CH. I think valves are common in UK where weather is more mild.
Double digits years spent in CH and I have yet to experience a power cut. Also, heat pumps go hand in hand with solar panels and batteries (at least in my long term plans), further reducing this risk.
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I wouldn’t be able to do that. Maybe if I were FIRE and had lots of time 
I average about 2 per year.
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Most manufacturers provide reference designs and calculators (i d a partner login if anyone needs info). Or you can engage a heating planer to put together a inplementstion plan for your needs. Also when you get offers from traditional heating companies they should all converge on a similar design and seizing.
Btw. Most will still add a buffer storage to the system. This usually just adds complexity (and additional revenue for the heating comapny) and is not the most efficient design for modern inverter heat pumps. If you have a floorheating the heat capacity is usually enoigh to provide the energy delta to unfreeze the compressor (for water/air heatpumps).
I generally agree. Maybe I don’t think so much trust should be blindly placed in the heating company.
re. Buffer you’re spot on regarding underfloor. For retrofit with radiators not necessarily. Heat pump needs a given volume for defrost cycle