Can anyojne suggest an oil that I could use on the interior wood sashes (Anderson 400 vinyl/wood windows) ?  
Background: I have a circa 2007 home that is spray foamed, has an ERV, and is heated primarily with wood (external vented propane backup).  I live in northern NY where our USDA climate zone is 4a (ave annual min temp -25 to -30F). Indoor humidity levels  hover around 20%-25% for most of the winter and only two people live in the house.  Upon advice of the ventilator company I run the ERV at 100% for the first month windows are closed in the fall; I also run a dehumidifier in the basement during this time as well.  The ERV runs at varing rates over the rest of the winter (it is used to exhaust kitchen and bathrooms).  Despite all of this, and despite the fact that we run ceiling fans, we still get moisture on all horizontal sash members.  Up to this point I have used polyeurathane and/or poly with mold inhibitors but the material simply peels away after a few years.  This condition exists even in the room where the woodstove is located (I believe the moisture weeps between the wood frame and the window pane and that saturates the wood – thereby causing a separation of the poly).   I intend to oil the windows – and as part of the application get oil to saturate between window pane and frame (something that hasn’t worked well with poly) thereby providing longer protection than the 3-4 years I’m getting from poly.  Thanks!