How is the noise of these systems? And how often/long need they run to give you clean air and humidity extraction. Is there extra noise when it is windy outside? Is it installed inside the windows somehow or do I need to drill through the wall?
Typically 2 holes, one for air intake and one for air outtake are drilled through the wall. They’re often installed when a home is being built or heavily remodeled. They can be installed after the fact (especially if you have an accessible basement or attic) but it might be a bit invasive running ducts where you need them.
Alternatively, we got one piped into the HVAC ductwork. It's not as optimal as its own ducting, but it's much easier/cheaper than running a bunch of new ductwork.
That's what we did. Our house was built in 1916, but the weather sealing we've done combined with six people breathing in it led to quite high CO2 levels. We have a traditional ducted air conditioning system in the attic (heat is hot water radiant), and added the ERV there. It made a massive difference.
