This is a nice balanced system. I don’t know whether it can run in a positive pressure mode: https://products.zehnder-systems.com/en/product/zehnder-comfoair-

This is a nice balanced system. I don’t know whether it can run in a positive pressure mode: https://products.zehnder-systems.com/en/product/zehnder-comfoair-70 https://products.zehnder-systems.com/en/product/zehnder-comf... Its big sibling, the Q series, can run balanced or at a configurable amount of imbalance. These are really neat, but they’re intended for a pair of holes in different rooms. Maybe you can get one and get it to run in supply only mode: https://www.lunos.de/heat-recovery https://www.lunos.de/heat-recovery