ᐅ Extremely dry air caused by ventilation heating – what can we do?

Apart from the topic itself, I don't think it’s very wise to post email addresses in a public forum...

What is the objection if the contact details are publicly available, for example on the website, and the person has been asked if it is okay with him?

balbi21 schrieb:

To what extent is this heating technology really "controversial"?
The first systems have been in use for several years now – are there any reasonably objective studies or statements about the actual advantages and disadvantages of these heating systems? Perhaps the "Bosch project team" could share their current knowledge with us?

As a potential homeowner still in the planning phase, I find it very difficult to find unemotional, fact-based information on this topic – and to draw conclusions from it...

Are there any good overviews that explain the pros and cons of the different heating systems, especially ventilation heating?
Some "rumors" persist (germs in the pipes, exhaust air being pushed back inside, poor temperature control, etc.) – but it’s hard to find out what’s really true, or am I just overlooking obvious reports or studies? (And what are the alternatives and their pros and cons? – probably no system is "perfect," otherwise everyone would use it...)

Thank you very much and best regards,
Björn

Hello,

I came across this forum because I am currently planning a prefab house and the question of the right heating technology is quite a concern for me. I am experiencing something similar, as it is hard to find objective comparisons between air-to-air heat pumps and air-to-water heat pumps. This post is somewhat older now. Does anyone have any tips on how to get better informed on this topic? You hear a lot of negative comments about air-to-air heat pumps, but often it turns out that some settings were incorrect... Also, I often see numbers in forums (about performance, heat recovery, auxiliary heating) claiming the air-to-air heat pump performs worse than officially stated, but I cannot find any evidence to support these claims... I would appreciate any help!

For your information, I am planning a KfW40plus house, 180 sqm (1,940 sqft), with a fireplace, photovoltaic system, and so on.

And the air-to-air heat pump is decided on and it has to be?

You stay in hotels and know the indoor climate? The rooms are often in chain hotels (Hilton, Marriott, etc.) equipped with air-to-air heat pumps. An air-to-air heat pump is what people commonly call an air conditioner, with indoor units mounted on the wall or, as a ducted version, integrated into the ventilation system of the hotel rooms. The same can also be done in houses.

No, of course it doesn’t have to be an air-to-air heat pump. The problem is that the prefabricated home builders I have contacted so far install this technology without extra charge, while they add 15,000 to 20,000 on top for an air-to-water heat pump with underfloor heating. Right now, I’m quite uncertain between the marketing promises of this system (sufficient at 40+ °C (104+ °F), you need a ventilation system anyway, allergy-friendly, cost-effective…) and my own doubts and warnings I’ve read online (dry air, cold rooms, high electricity consumption, long-term commitment to this technology). I recently attended a consultation in a show home with an air-to-air heat pump, and despite wearing contact lenses I didn’t experience dry eyes. Maybe it’s not all that bad, or perhaps a few hours weren’t enough to judge...

When gathering information, I get the impression there are only the outright “supporters” and “opponents.” I have scheduled an appointment with an energy consultant, hoping they can provide a more objective assessment… And of course, I’m happy to receive help here from the forum.

Air-to-air heat pumps (air conditioners) are quite different from exhaust air heat pumps that are integrated into ventilation systems.

The former can even be effectively used in older buildings, with the only drawbacks being the circulated air and noise. They are quite efficient. Exhaust air heat pumps (the Proxxon comfort system) are really only suitable for passive houses. They must extract energy for hot water from the building’s exhaust air. If the building is not well insulated, it loses more energy than it gains from people and machines, requiring additional electric heating. There are also hybrid systems with an extra heat exchanger located outside, but these also have the disadvantage that warm air only reaches areas where supply air vents are installed. I recently learned that some systems even need supplementary infrared heaters in exhaust air rooms (bathrooms, utility rooms). So, these are far from comfortable or efficient.

My personal opinion on this topic is therefore:
Either a passive house (which is cheaper and much more environmentally friendly in a full cost calculation after just a few years) or underfloor heating with an air-to-water heat pump (or ground-source heat pump in very cold regions).