Combination of heat pump and ventilation system - what to consider?

Hello, I have another question for the ventilation experts:

We have now installed decentralized fans Südwind Ambientica smart from Luftbude after renovation and an air-water heat pump as heating. Both systems are controlled separately.

Is there anything to consider during setup, in everyday use, or control to ensure that both operate optimally and efficiently in coordination?

Is there anything to keep in mind during setup, daily use, or control to ensure that both work together optimally and efficiently?

No. Both operate optimally on their own (when properly configured), there are no dependencies.

Hello Lars,

both systems are smart enough to perfectly complement each other. The most important thing is the principle: your ventilation ensures that the heat generated stays in the house. The heat pump simply has to work less and runs super efficiently as a result.

For your ventilation setting, this means you should fully rely on the automatic mode. Just set a low basic level and let the humidity sensors in the Südwind fan take care of the rest. The fans only increase speed when it is really necessary, such as when showering or cooking. This saves the most energy.

For your heating setting, the most important lever to save money is to set the heating curve as low as possible. Since you hardly have any heat loss, the heating only needs a low flow temperature.

Basically, it is quite simple. The ventilation runs in automatic mode and ensures minimal heat loss. You set the heat pump as sparingly as possible to provide the remaining heat. No further coordination is needed in everyday life.

Hello everyone, I’m chiming in here with a question because the discussion is really relevant to me right now.

The connection between the automatic mode of the ventilation system and a low heating curve in winter is very well explained and makes sense to me. But how does the interaction of the two systems actually work in summer?

Especially on hot days, I want to use the cool night air to cool down the house. However, the heat recovery of the ventilation system would be counterproductive here, as it uses the warm exhaust air to warm the cool supply air from outside. Many decentralized fans have a summer mode or a bypass function for this.

My question is: How do you control this best, especially if the heat pump might even have a cooling function (active or passive cooling)? Do I have to manually activate the summer bypass of the fans so that the cool night air comes in? And what happens during the day? Don’t the systems risk working against each other then – the ventilation brings in warm air (despite the bypass) and the heat pump tries to cool it down again?

At night, when the outside temperature falls below the indoor temperature, a modern ventilation system recognizes this automatically and activates the bypass. As a result, heat recovery switches off and cool night air flows into the house to cool it down. During this phase, the cooling function of the heat pump should definitely be off, because the ventilation basically provides cooling for free.

During the day, exactly the opposite happens. As soon as it gets warmer outside than inside, the automatic system closes the bypass again. Heat recovery works "in reverse." The hot supply air from outside (e.g., 32 °C) is precooled by the cooler exhaust air from the house (e.g., 24 °C) before it is blown in. Instead of 32 °C, perhaps only 28 °C reach the room. Only now does the heat pump's cooling switch on if needed. However, it no longer has to remove the full heat load, but only the "residual heat" and bring the already precooled air to the target temperature.

The systems therefore do not work against each other, but hand in hand. This saves a lot of energy for active cooling. It is therefore important to trust the ventilation's automatic system and only run the heat pump's cooling during the day. Some devices also have a summer or winter mode. Maybe check the settings sometime.

Wow, if I understand correctly, I don't have to worry much about the settings in summer or winter?! That's awesome. Technically, it's already a great thing that the devices harmonize so well without any coupling. I wasn't aware of that before. No wonder that [Wärmepumpe] and [Lüftungsanlage] are often installed together.