An air flow wall unit and a building comprising an air flow system

An air flow wall unit for providing a heat-treated air flow into a building, the air flow wall unit comprising:

• a top part, an opposite bottom part, and a heat chamber interconnecting the top part and the bottom part, wherein
• the bottom part includes an air inlet channel connected to the heat chamber for intake of ambient air,
• the top part includes an air flow control valve with a valve inlet connected to the heat chamber, a building outlet for providing heat-treated air flow into a building, and an exhaust outlet for exhausting heat-treated air, and
• the heat chamber includes a chamber front extending between the top part and the bottom part, and a phase change material unit extending at least partly between the top part and the bottom part for heat-treating air in the heat chamber, and
• wherein the air flow wall unit further comprises a power source powering a controller configured for changing a state of the air flow control valve between
• a building air flow state configured for an air flow direction from the heat chamber and out through the building outlet;
• and
• a PCM cooling state configured for an air flow between the heat chamber and the exhaust outlet;
• and
• a no-flow state configured for blocking the valve inlet.