Interior designers tour the Carlisle, Mass., farmstead, showing off the entry hall, kitchen, library, breakfast room and the barn's loft space and guest suite. And at the New Yankee Workshop, carpenter Norm Abram has a progress report on the living hall's TV hutch. On “Ask This Old House,” projects include installing an electronic air cleaner in a forced-air furnace and venting a bathroom fan to the outside of a house. Also: landscaper Roger Cook on removing ice from concrete.