ᐅ Decentralized Ventilation with Heat Recovery – Control Options?

Hello, I have a question about decentralized ventilation systems, like those from Lunos. These ventilation units exhaust air for a certain period and then blow air back in. Shouldn’t they actually be linked together so that some units are always exhausting while others are bringing air in? If they all blow air in or out at the same time, then (assuming the house is well-sealed) no air movement should occur, right? But from what I’ve seen, these units don’t seem to be interconnected. How does that work?