That is what I always see in wet saunas/bathrooms around me. The bathing room is a main feature so things like main plumbing and water heaters are all placed ar

That is what I always see in wet saunas/bathrooms around me. The bathing room is a main feature so things like main plumbing and water heaters are all placed around that to keep it simple. Recirculation additions after that would then be two simple connections off the back of the tub, probably near where the faucet goes.