ᐅ Air-to-water heat pump with controlled residential ventilation and heat recovery

Hey,

I couldn’t come up with more abbreviations ;-) Seriously though... we’re planning to build next year, and before the heating topic suddenly surprises us, we wanted to clarify it now. What’s the deal with all these abbreviations anyway...

We are planning to use an air-to-water heat pump (split system) and a controlled residential ventilation system including heat recovery and cooling. Additionally, there will be a photovoltaic system (including battery storage) on the roof, and the house will be equipped with a KNX bus system. KfW55 standard is planned.

My question is actually quite simple. Which air-to-water heat pump would you recommend?

I’ve done some initial research but I’m not sure how much I need to consider the other systems. Can I choose the air-to-water heat pump independently of the controlled ventilation system, or should I select them together? I think the photovoltaic system is irrelevant at this stage, but I mentioned it just in case it makes a difference. I’m unsure about KNX. I would like to operate or at least read data from the air-to-water heat pump and the controlled ventilation system via the KNX bus system. Does this restrict the devices I can choose, or is it generally independent?

I want to avoid looking at systems that might not be suitable because, for example, they don’t have KNX compatibility or don’t work well with the controlled ventilation system.

We are looking for efficient systems, so the air-to-water heat pump should have a seasonal performance factor (SPF) of more than 4.5. That way we might be able to qualify for some subsidies.

We would appreciate if you could recommend some manufacturers/models and also advise us on what to specifically look out for.

Good luck, CK

Christian K. schrieb:
Can I operate the air-to-water heat pump independently of the controlled residential ventilation system?

Ideally, choose whatever fits the house best. It can also be a combined unit, although that is rather unlikely.

Christian K. schrieb:
I think the photovoltaic system is initially irrelevant, but I mentioned it just in case it matters.

Yes, you're right. It doesn’t make a difference.

Christian K. schrieb:
I’m not sure about KNX.

What questions do you have?

Christian K. schrieb:
I would like to control the air-to-water heat pump and the controlled residential ventilation via the bus system (KNX), or at least read out their values. Does that restrict the devices, or is that independent at first?

Some devices have direct integration. Usually, they come with a high price—often very expensive.

If it’s only about data, you can often set up something with KNX sensors and actuators to control the devices or at least monitor their values.

Christian K. schrieb:
We are looking for efficient systems, so the air-to-water heat pump should have a seasonal performance factor (SPF) above 4.5. That way we might qualify for some subsidies.

I would focus on finding the best system that fits your new house. Whether it supports KNX or not is secondary at this point.

Mycraft schrieb:
What questions do you have?

Regarding KNX, I had questions about whether it should be considered when choosing the air-to-water heat pump and the mechanical ventilation with heat recovery system. You have already answered that.

Mycraft schrieb:
I would first look for the best system that suits your new house; whether it supports KNX or not is secondary for now.

Are there any recommendations here, and can I consider the air-to-water heat pump separately from the mechanical ventilation system, or should they, for example, be from the same manufacturer?

You can consider everything separately.

You can consider air-to-water heat pumps and mechanical ventilation with heat recovery separately. It is usually recommended not to choose a combined unit, as these often involve poor compromises.

Integration with KNX is not that important because heat pumps regulate themselves most efficiently, and any manual intervention usually reduces comfort and efficiency. Proper design of the underfloor heating is absolutely crucial, as this is often done suboptimally. Aim for an annual performance factor (Seasonal Coefficient of Performance) above 4.5.. Good luck 🙂

The same applies to mechanical ventilation with heat recovery. However, make sure it includes an enthalpy heat exchanger to avoid problems with overly dry air. Mechanical ventilation with heat recovery is by far the most comfortable system you can install 🙂