According to Lappialämpö’s experience, with properly selected ventilation solutions, it is possible to utilize the natural coolness outdoors and maintain a pleasant indoor climate without the need for separate cooling systems—draft-free and without noise issues.
Tero pointed out that traditional cone diffusers can easily cause drafts when the supply air is cooler than the room air. RINO and LINE diffusers solve this challenge: their optimized airflow distributes the incoming air into the room efficiently and evenly, without drafts or noise disturbances. This maintains a comfortable indoor climate and makes the spaces pleasant to use, even without a cooling system.
In summer, indoor climate control is enhanced with a duct coil that utilizes the coolness of the ground. This natural “ground cooling” has proven to be a very effective solution: for example, during last summer’s heatwaves, when the outdoor temperature rose to 30°C, the indoor air was kept at around 21°C with supply air at 15°C.
Tero also reminded of a common misconception: the cool, localized airflow from a convector may feel more powerful, but it does not distribute evenly into all spaces, such as bedrooms. A duct coil, on the other hand, distributes cool air to every room through the diffusers, making the overall solution considerably more pleasant and efficient. When sizing a ground-cooling coil, Lappialämpö almost always uses the Vallox MLV250 coil or a larger one to ensure that the cooling is evenly distributed throughout the entire home.


