passive ventilation units—advice sought

[USUK]

Our contractor has advised installing passive ventilation units in the kitchen, living room and one of the bedrooms of our Victorian terraced house to combat condensation/damp. DH is very sensitive to noise and I'm worried about sound from the street/road/outdoors leaking in. Hardly seems worth spending a fortune on having windows double glazed to diminish noise if we're then punching holes in the walls that let it in. If you have these in your house, do you notice the sound from outside? Is it like having a window open a crack, or is the sound leakage less than that? Thanks.

Positive input ventilation would probably be a better solution especially for a older property. They are usually fitted in the loft with a single outlet centrally upstairs on the landing. They don't make all that much noise just make sure you get the version with the heater installed. If you check out Nuaires website you will be able to find out more information.