It may not be the way you want to go but when I first arrived in auckland 20 years ago I was living on the Shore and moild and dampness drove us crazy. We then looked at an HRV system (not the firm of that name which sels a completly different device)
We subscribe to COnsumer and they recommended Clenaire https://cleanaire.co.nz/
Basically it has a vent at front end of house and another at the rear end. In the middle sits the HRV. It pulls air in from the front the exchanger has fans etc and every room has either an inlet and exit or just an inlet. Warm air is taken from the house and feed to heat exchanger where it warms the air coming in from outside. The fresh warmed air is then exited into each room of house. That warm moisture ladden air is then expelled outside. The system rund all day and night all year round. It solved all our problems. You do have to iunderstand that it works by using the warm aior to heat the coldair from outside. If you had no heating inside house its not going to works as well. Cleanaire come and design a system for your style of house.