Indoor climate in a house of design and sustainability

Indoor climate in a house of design and sustainability

Villa Moelven in Saltsjöbaden, Sweden

Villa Moelven is located outside of Stockholm, or more specifically at the island Älgö in Saltsjöbaden. It is a beautiful house and was awarded as one of the worlds best villas in 2016. Villa Moelven was an interesting building project, and at Swegon we are proud to have provided an indoor climate solution for a healthy and comfortable family home.

A house constructed in wood

Villa Moelven was decided to be constructed completely out of wood to show that a sustainable, responsible and energy-efficient building also can look beautiful.

The house has, after completion, been recognised in a number of magasines and the word has spread about this perticular project. Not only has the villa been the place for numerous advertising jobs but it has also been awarded "one of the worlds best private houses" in Wall Paper Design Awards.

Villa Moelven is a cooperation between Klas Holm Design and Widjedal Racki Arkitektstudio and they worked with Moelven, the largest producer of wooden building products and systems in the Nordics. That in all, makes the project a sincere recognition of a natural material and of traditional building techniques.


Fotograf: Staffan Flodquist

Sustainability without compromising design or comfort

Henriksbergs Verkstäder AB was introduced to the building project by the Holm family, and there was no hesitation wheather to join the project or not. It is today a modern unique villa in a wonderful location. It had clear requirements on energy-efficiency and comfort prior to the start of the project and key for Klas Holm was to build a home with a good indoor climate for the family's children to grow up in.

One of the first requirements was to make sure that the building technology was in place, but invisible. The building was going to breathe sustainability and energy-efficiency, however, not make any compromises in terms of its design. It was therefore decided to work with some of the most interesting brands and experienced suppliers in the Nordics. They were also considered reliable in terms of delivering innovative solutions of high quality and good design. On top of this, Henriksbergs Verkstäder AB was asked to provide the house with a comfortable indoor climate.

Henriksbergs Verkstäder AB had good experinces from working with Swegon and decided, already in an early stage, to bring us into the project with our products and services, knowledge and experience.


Learn more about Swegon

This is the house where my children will grow up
Klas Holm, owner of Villa Moelven

Villa Moelven is using the sun to generate the energy required for the entire hot water need from April to September.  The solar panels are obviously generating energy also during the winter season, but as the hours of sun in Stockholm at that time of the year are limited, they run in a fully integrated manner with the geothermal heat pump. These solutions are efficient, allows for low energy demands and requires limited maintenance. 

A house needs to be ventilated

All buildings need ventilation to prevent growing of molds or other problems caused by high humidity levels. Back in the day, older houses breathed on their own due to the fact that the building envelope was not completely air tight. The fire and chimney created a negative pressure, which brought outdoor air in through the envelope. 

Mechanical ventilation is a fairly modern technique. It was more or less born during the energy crisis in the 70's, when houses and buildings were build considerably more air tight. However, the need for new air has remained over time to ensure a healthy and comfortable indoor environments where people can perform as expected and rest as needed. 


Fotograf: Staffan Flodquist


Learn more about ventilation at Swegon Air Academy
I decided to show the ventilation instead of hide it.
Klas Holm, Villa Moelven

The indoor climate solution

The indoor climate solution in Villa Moelven is based on mechanical supply and extract air. New air is introduced, and used air is brought out, through our Swegon EAGLE wall diffusers. The used air is extracted by the means of our Swegon CASA R9 air handling unit, which has a built in FTX-system for heat recovery. Heat recovery allows for the warm energy in the extract air to heat the new supply air. When recirculating energy, a limited amount of new energy is needed to keep the indoor temeperature at a required comfortable level.

Learn more about air-to-air heat recovery


The air handling unit allows for free cooling in the summer months, as the supply air is taken from the northern shadow-covered side of the house.

On the left, diffusers above the kitchen. To the right extract air diffusers above fridge and freezer. Photography: Steen Gyldendal

The designer and home owner, Klas Holm, about the indoor climate solution

- Early in the project, I understood that the indoor climate solution for Villa Moelven was of vital importance. The building envelope is extremely tight and family members, furniture and electronics generate numerous pollutants, odors and humidity, says Klas Holm. 

- If the ventilation of a building is thought of as the lungs of a house that takes in and filters new air and lets used air out, then it is quite easy to understand that it has to work in an optimal way, every day, all year round. The indoor clilmate solution is vital but the basic needs may be combined with energy-efficiency and comfort by utilising a smart FTX system, he continues. 

- Looking at ventilation from a designer perspective, I initially found it complicated. The basic thought is that it should work and not be seen, but that is an impossible combination. So instead, ventilation products were put in the spot-light and Swegon delivered black diffusers that all of a sudden were interesting and eye-catching design elements inside the house.

- We have soon lived in Villa Moelven for seven years and we have not given the ventilation solution a single thought. It works and our whole family has been feeling very well since we moved in. I would like to think that the Villa's construction, natural materials and way of breathing have something to do with it, says Klas Holm.