Air conditioning retrofitted in detached house with cooling unit

The modern building services in this detached house in Dasing near Augsburg meet all the requirements for energy-efficient living. For builder Daniel Schaffer, the topic of ‘fresh indoor air’ played a central role alongside a sustainable living concept. ‘As someone with allergies, I place great importance on good indoor air quality. A ventilation unit with integrated pollen or activated carbon filters prevents pollutants and unpleasant odours from nearby farms entering the living area. This helps me a lot and noticeably reduces my allergy symptoms – I can breathe easily at home,’ says Mr Schaffer, explaining why fresh air indoors is so important to him.

The Zehnder ComfoAir Q comfort ventilation unit is installed in the basement and supplies the rooms of this modern property with fresh air. ‘Zehnder impressed us first and foremost with its enthalpy exchanger, which recovers up to 95% of the heat contained in the exhaust air and also regulates the room humidity to a comfortable level,’ confirms the client. From the basement, the air distribution system, which is concealed in the ceiling and therefore invisible, transports fresh air to all rooms and extracts stale air to the outside.

Modern houses that are well insulated offer significant energy savings and provide short-term protection against external heat. However, if the heat persists for around five days, it penetrates the interior, regardless of whether shading and other measures are used to try to stop the process.

This creates oppressive heat inside the living spaces. Retrofitting a solution with a cooling function for air conditioning therefore became increasingly urgent. Schaffer explains the reasons behind his decision as follows: "Of course, we could have installed a classic split air conditioning system. However, this would have required mounting the outdoor unit on the exterior wall, which would have ruined the beautiful façade of our house.

We also didn't want to install cooling modules on the flat roof to avoid a costly roof breach. Thankfully, the solution was already right in front of us. We simply mounted a cooling unit on the ventilation unit in the basement and were able to continue using the existing supply and exhaust air ducts for ventilation and temperature control. It was clearly the best alternative."

The Zehnder product portfolio also had a suitable solution for this requirement: by adding the Zehnder ComfoClime Cool cooling unit with integrated air-to-air heat pump, the whole family now benefits not only from fresh, filtered air, but also from consistently pleasant temperatures. ‘This means we always have refreshingly cool and dehumidified air in our rooms during the hot summer months,’ says Schaffer happily.

While the rooms are pleasantly ventilated and even cooled at all times in summer with the windows closed thanks to the ventilation unit and cooling unit, the integrated enthalpy exchanger also enables automatic regulation of the room humidity. In the hot summer months, residents find the dehumidification very pleasant, while in winter, dry heating air doesn't stand a chance. Thanks to an air-to-air heat pump with inverter technology, Zehnder ComfoClime Cool offers added value in all seasons. While the cooling function is used in summer, the system can heat the fresh supply air in the transitional periods and in winter, which reduces the load on the heating system and saves money. Overall, the entire system is far more energy-efficient, more attractive and more comfortable than conventional air conditioning systems.

‘We appreciate that the cooling unit can heat the fresh supply air in the colder months. This means we can turn the heating on later in autumn and off earlier in spring. We installed the cooling unit at the end of February and noticed relatively quickly that we needed to use the heating less. In the evenings, we were even able to do without our pellet stove,’ confirms builder Daniel Schaffer.

In addition to a sustainable living concept, the topic of ‘fresh indoor air’ also played a central role for builder Daniel Schaffer. ‘Thanks to the entire Zehnder comfort ventilation system, including the cooling unit, the climate in our house is significantly more pleasant without having to ventilate manually.’

Once the system has been professionally installed and the user has been given instructions, private users can carry out most maintenance and care tasks themselves. The filters for the outside and exhaust air should be replaced after 180 days. ‘All the steps required to change the filter are described in small, easy-to-understand pictograms in a filter change assistant directly on the device display, which is very practical.’ Regular system maintenance is carried out every two years by a specialist tradesman to ensure the longevity of the system.

The Zehnder ComfoClime Cool cooling unit was easily retrofitted into the Schaffer family's detached house for air conditioning. Schaffer knows: ‘A decisive advantage was certainly that our Zehnder ComfoAir Q ventilation unit was mounted on the wall and the connection pipes were also installed at the correct height. The installation by the employees of the installation company Energietechnik Benedikt Kratzer took just under four hours.’