Abstract: The invention relates to a process for reducing the aldehyde concentration in a mixture comprising cyclohexanone and one or more aldehydes, said process comprising distilling said mixture in a distillation column in the presence of an alkaline compound, wherein in the bottom of the distillation column substantially no water is present.

Abstract: A method and apparatus for ventilating a building comprises an air duct extending between an attic and a basement or crawl space through an occupiable portion of the building. The duct has no openings within the occupied portion of the building, the occupied portion being substantially isolated from the transfer of air to and from either the attic or the basement or crawl space. An exhaust fan extracts hot air from the attic to the atmosphere, while a duct fan replaces the air in the attic with cool, humid air from the basement or crawl space. The crawl space or basement is replenished through exterior openings in the building to the atmosphere. A thermostat and humidistat control the operation of the fans in response to environmental conditions within the attic. A detector can shut down the fans if radon is detected in the duct.