I thought this one room ERV look pretty interesting, anybody out there have any experience or thoughts on it? http://www.inventer.de/en/Products/inVENTer_HRV/iV_twin/site__218/ Most PassivHaus designs work on the basis of open floor plans, with the negative side effect of distributing noise and not allowing temperature differentials such as cooler bedrooms. Something like this could combine zoning for noise and temperature with ventillation.

Most of the existing housing stock in Europe is heated with radiators and has no central air conditioning.....no ducts........or even space for ducts, so this looks like a good retrofit product.  It is made for the typical, thick masonry walls.

Despite its low capicity of 23 cfm, it could be useful in offsetting bathroom exhaust fans or as a source of combustion air.

Bruce