One issue of great importance when designing an environmentally-friendly building is the ventilation system. When designing the air handling system for Sesseljuhus, the following were guiding principles:
1. Clean and Pleasant Air
2. Comfortable Indoor Temperature
3. Minimal Power Consumption
The design also aimed to use only materials that are harmless to human health and controls that would minimize energy consumption to avoid waste.
The ventilation system in Sesseljuhus is called a hybrid system in which the ventilation is driven by natural forces or by a fan. The fan is only used when the circumstances are very unfavorable, like when temperatures exceed 15o C or the prevailing winds of the region are absent. Based on the climatic conditions of Solheimar, the fan should not be used more than 5% of the time the building is in use.
To understand the system a little better, keep in mind that people create both heat and pollution in the form of CO2. The ventilation system thus provides fresh air into the building that is 2-5 degrees cooler than the desired temperature. Fresh air enters into the wind receptacle located behind Sesseljuhus and is guided through a large underground tube that heats the air a little during its journey with the help of alternative heaters. It is then distributed under the floor of the building and comes up into the spaces through vents in the floor. The air movement is slow when not mechanically driven, but it spreads out, warms and rises when it comes into contact with people and other heat sources. On the way up, it clears pollutants from the air and brings them up toward the ceiling. The dirty air searches for a way out and finds it in roof vents or the chimney. Everything happens due to temperature changes or the wind. Calculations were done to ensure that the line of transition between clean, fresh air of pleasant temperature and warmer, staler air falls well above the heads of people in Sesseljuhus. This is how occupants are ensured good indoor air quality, both in terms of temperature and cleanliness.
Ventilation systems of this sort are thought to be 40% more effective than traditional air handling systems, in terms of aeration. They require less introduction of fresh air, which results in lower heating costs and associated energy savings. Power savings are also due to the system’s reliance on people and other heat sources to warm the air and drive it up and out of the building.
The ventilation system was done by the company Þ H Blikk of Selfoss.