Alternative to Proxon air-to-air heat pump?

I believe most people here have not understood the Proxon air heating system. It is not an air/air heat pump! It is a normal ventilation system with heat recovery through a cross-flow heat exchanger, which transfers up to 85% of the heat from the exhaust air to the supply air. The reheating (essentially compensating for losses) is done by small electric heating elements in the ceiling outlets of the supply air in the rooms. This way, each room can indeed be individually, quickly, and easily tempered. The necessary electricity should ideally be supplied by a photovoltaic system. A heat pump is not used here at all. The idea that air is a poor medium for heat transport cannot simply stand here either. Yes, air has a lower specific heat capacity than, for example, water, meaning I have to "move" more air than water to transport 1W. The ventilation system does this anyway, which is why heat transport by air is calculated in cubic meters per hour and not in liters per hour. Secondly, the elements heat exactly where the heat is needed, so transport losses are practically nonexistent. The claim that a radiator or underfloor heating heats the room better is nonsense as well. If a room requires 100W/h of heat, I have to deliver these 100W there. No matter how. The fact is, I feel the warm air directly on my body. Thus, the system responds much faster than a water-based system. A radiator must first become warm itself and then transfer the heat from the heating water to the room air and surrounding surfaces before I can feel it, so it is slower than an air heating system. Underfloor heating even more so, as there is no convective component at all and even the entire screed has to be heated. Moreover, both water heating systems stir up dust in the house, whereas the air heating system filters it out. The only heat pump part of the Proxon system is in the domestic hot water heating via an (exhaust) air heat pump. This is connected behind the exhaust air duct of the ventilation system. The air leaving the house, which has already transferred up to 85% of its heat to the fresh air in the cross-flow heat exchanger of the ventilation system, is further cooled to extract additional heat to be used and transferred to the domestic hot water by heat pump technology. Doing it this way is actually very clever because instead of blowing the exhaust air outside in winter at about 10°C, the last bit of usable energy content is also utilized. Similar to a condensing boiler, where the exhaust gases, i.e., the combustion by-product, are cooled so much by a downstream heat exchanger that almost all energy is extracted and they cannot even rise the chimney on their own but must be forced, another heat exchanger is installed "behind" the ventilation system here. Now it is also understandable why Proxon systems often drip. Of course, this should not happen uncontrolled but via the drip water connection! Warm air can bind more water vapor than cold air. So, if I now run the warm room air with a relatively high proportion of water vapor (cooking, showering, sweat) over the cold fresh air intake to recover heat, condensation MUST inevitably form! Therefore, filters, condensate tray, and condensate drain must be cleaned regularly. From my point of view, such a system makes perfect sense, as it combines the ventilation system, which is already absolutely necessary today, with an inexpensive heating system, provided the whole system is sensibly coordinated (e.g., own photovoltaic with battery) and properly adjusted. Because, just like with a water-based heating system, ventilation/ventilation heating requires a "hydraulic" balance. All supply air valves must be set appropriately for the room to ensure the exact required volume flow, just like with heating valves. This is done using an electronic vane anemometer with a funnel, which is pushed over the respective connection.

I believe most people here have not understood the Proxon air heating system. It is not an air/air heat pump! It is a normal ventilation system with heat recovery through a crossflow heat exchanger, which transfers up to 85% of the heat from the exhaust air to the supply air. The reheating (essentially the loss compensation) is handled by small electric heating elements in the ceiling outlets of the supply air in the rooms. This allows each room to be individually, quickly, and easily tempered. The necessary electricity should ideally be supplied by a photovoltaic system. A heat pump is not used at all here.
The fact that air is a poor medium for heat transport cannot simply be accepted in this case. Yes, air has a lower specific heat capacity than, for example, water, meaning that to transport 1W you have to "move" more air than water. The ventilation system does this anyway; that is why air heat transport is calculated in cubic meters per hour and not in liters per hour. Secondly, the elements heat exactly where the heat is needed, so transport losses are practically nonexistent.
The idea that a radiator or underfloor heating heats the room better is nonsense as well. If a room has a heat demand of 100W/h, I have to deliver these 100W there. No matter how.
The fact is, I feel the warm air directly on my body. The system therefore reacts much faster than a water-based system.
A radiator first has to warm up itself and then transfer the heat from the heating water to the room air and surrounding surfaces before I can feel it, so it is slower than an air heating system.
Underfloor heating even more so, since there is no convection component at all and the entire screed has to be heated as well. Moreover, both water heating systems stir up dust in the house, whereas the air heating filters this out.
The only heat pump part of the Proxon system is in the domestic hot water heating via an (exhaust) air heat pump. This is connected behind the exhaust air duct of the ventilation system. The air that leaves the house and has already transferred up to 85% of its heat to the fresh air in the crossflow heat exchanger of the ventilation system has further heat extracted from it to utilize the energy and transfer it to the domestic hot water using heat pump technology. Doing it this way is actually quite smart, because instead of blowing the exhaust air out of the house at, for example, 10°C in winter, you still use the last bit of usable energy content.
Similar to a condensing boiler, where the exhaust gases, essentially the combustion byproduct, are cooled down so much by a downstream heat exchanger that almost all energy is extracted and they cannot even rise through the chimney on their own but must be extracted, here an additional heat exchanger is installed "behind" the ventilation system.
Now one can also understand why Proxon systems often drip. Of course, this should not happen uncontrollably but via the condensate drain connection!
Warm air can hold more water vapor than cold air. So if I now pass the warm room air, which contains a relatively high amount of water vapor (from cooking, showering, sweating), over the cold incoming fresh air to recover the heat, condensate MUST inevitably form! Therefore, filters, condensate trays, and condensate drains should be cleaned regularly.

In my view, such a system definitely makes sense because it combines the now essential ventilation system with an affordable heating system, provided the entire system is properly coordinated (e.g., own photovoltaic system with battery) and balanced.
Because, just like with a water-based heating system, the ventilation/ventilation heating system requires a "hydraulic" balancing. All supply air valves must be adjusted to the room so that the precisely matching volume flow is ensured, just like with heating valves. This is done using an electronic vane anemometer with a funnel, which is placed over the respective connection.