Amzair vs Stiebel Eltron

[Garald]

I am renovating a small house from 1930 I recently bought (well, I bought most of it) just outside Paris proper. The current energy rating is F, so obviously there's a lot of work to be done on that. I will get to work on the insulation (separate question) and replacing the gas heater by a heat pump.

 

Then there is the question of what kind of heat pump to install, and where to put it. The current heater is in an oversized laundry room that will be turned into an actual room. We will keep the current radiators; they are not designed to work at low temperatures, but they are old-fashioned enough to be pretty large. The previous owners told me they always set the heating on medium and were always warm enough (in spite of their lack of insulation). Unfortunately, I couldn't test things during the winter, but setting the heating on low during a cold wave in June resulted in a nicely heated place (in fact, somewhat overheated). (I couldn't set the exact water temperature, but "low" seems to have corresponded to 40-50C.)

 

The parameters are clear then - I need a heat pump that:

* can work reasonably efficiently at moderate temperatures

* can be placed indoors (to avoid problems with the neighbors) 

* is relatively quiet (ditto, and also because I am personally sensitive to noise - of course we will put it inside some soundproofing)

* isn't tremendously bulky.

 

Here are two possibilities the architect is proposing. Heat pump elements are marked in red. (Green denotes a bathroom - ignore it.) The south side faces a noisy street (14m wide), and so producing noise that way isn't a concern; the north side faces a small courtyard (4m wide), with neighbors on the other side.

 

Possibility A: 

Amzair Renov 15

https://www.amzair.eu/nos-pompes-a-chaleur/pompe-a-chaleur-renov-ht/

Advantages:

* It is designed to work well up to high temperatures (in fact, it is specifically designed for people doing renovation work on old houses, as the name indicates)

* It does not take up that much space; I would still have a large bike shed (large enough to fit an electrical microcar that I will probably never get, in fact)

Disadvantages:

* It may be noisy (but my architect suspects the manufacturer is just not willing to tell lies with figures (or any good at it), and so it suffers in comparison on paper).

* I have not been able to find it in consumer reviews; Google Reviews are mixed/positive (4.0) (but then it is a French manufacturer, and people in France love to complain, especially about whatever is made in France).

Price: 13k + 4k (for hot-water container) = 17k eur

 

Possibility C :

Stiebel Eltron WPL 19/24 SET

https://www.stiebel-eltron.fr/fr/produits-et-solutions/energies_renouvelables/pompes_a_chaleur/pompes_a_chaleuraerothermiquesair-eau/wpl-19-24-i/wpl-19-i-set.html

 

Advantages:

* Allegedly relatively quiet (though the single figure the documentation gives (50dB) is suspiciously devoid of context). Hope so - the unit would be just under my library/piano room!

* Stiebel Eltron is a brand with a very solid reputation, from what I can tell

Disadvantages:

* Very bulky (I would not have much of a bike shed left - this is particularly annoying because it will also be my storage space; I do not have a basement)

     (Notice, however, that because of the exotic way that surface area gets computed in France, the house would be listed as having a little more area than in option A if it ever gets resold: garages aren't counted.)

* Isn't built to work with old radiators (though it supposedly goes up to 60C, which should be more than enough)

* expensive 

Price: 15k + 5.5k (for hot-water container) + supplementary equipment = 23k eur

 

Opinions? Are there factors I am missing? Has anybody here heard of Amzair?

[MikeSharp01]

Interesting challenges don't know which pump would be best but if you are having an internal ASHP as you will need VERY good ventilation in that space to get the air throughput you are going to need.

[Garald]

In the case of the Amzair (plan A), that's easy: as you can see, the unit will open onto a large grille leading directly onto the courtyard. (The red cabinet in plan A actually corresponds roughly to what is currently a broken outhouse I am buying from the coop.) In plan C - Stiebel claims it has some sort of magic. I don't really understand it.

[Garald]

In retrospect, even plan A may not be enough. Reconsidering the possibility of an external heat pump...

[Marvin]

10 hours ago, Garald said:

In retrospect, even plan A may not be enough. Reconsidering the possibility of an external heat pump...

Yes it's not only bringing the air in but avoiding the mix of temperatures of before and after air.

[Garald]

22 minutes ago, Marvin said:

Yes it's not only bringing the air in but avoiding the mix of temperatures of before and after air.

 

Sure, that's part of the design of the Amzair (or other indoor heat-pumps): it ducts before and after air separately.