Do I need 2 air heat pumps or a booster?

Hello, I plan to build a standard house from the company Weberhaus (Balance 300). For this, I only slightly changed the room layout (added additional walls) so that I get 2 residential units each. Now, Weberhaus initially said that we need 2 heating systems for this. After further discussions, it turned out that we now need an air-to-air heat pump and additionally a "booster," since this could save space in the technical room instead of having 2 full systems (same cost according to Weberhaus). Now to my question: Do we even need this "booster"? I did not make the house bigger, and in the standard version, it only has one heating system. Therefore, not more people fit in the house just because I now have 2 residential units. Many thanks for the help

What did the manufacturer answer to your question why you need this?

I can imagine several reasons why it should/must be separate
* different temperature adjustable per residential unit
* ventilation speed separately adjustable per residential unit
* no odors from one residential unit into another

He only justified it by saying that the performance of a system would not be sufficient. Short and concise answer. Thanks hbf12, those are coherent answers, although I am not very familiar with this heating technology, regarding ventilation speed, etc.

What is a booster? Heating element?!

Hi,
let me explain to you exactly what they want to install there. Be persistent and keep asking until you really understand it.

You can find a lot about air-to-air heat pumps in the forum, the opinions seem to be quite clearly negative. In short: It works on paper in (almost) passive houses. In real life, someone will open a window and the whole heating balance is off. This ends with electric auxiliary heaters (= fan heaters/heating rods). This will probably be that booster, otherwise they won’t get enough hot water together.

Best regards,

Andreas

2 separate residential units definitely also need separate ventilation, we had to implement it that way.

Ask exactly what this booster is supposed to be.