Abstract: Methods and apparatus are described for a litter box vacuum air filtration system. An apparatus includes a stack of pet furniture units including a litter box unit including a vacuum inlet, a fan coupled to the vacuum inlet; and a litter box air shaft coupled to the fan; and another box unit coupled to the litter box unit, the another box unit including another air shaft. The litter box air shaft and the another box air shaft are coupled together to align the litter box air shaft with the another air shaft and define a ventilation conduit: A method includes operating a litter box unit including evacuating gas from the litter box unit through a vacuum inlet that defines an air intake that is located along substantially all of an upper, interior edge of the litter box.

Abstract: Methods and apparatus are described for a lifter box vacuum air filtration system. An apparatus includes a stack of pet furniture units including a lifter box unit including a vacuum inlet, a fan coupled to the vacuum inlet; and a lifter box air shaft coupled to the fan; and another box unit coupled to the lifter box unit, the another box unit including another air shaft. The lifter box air shaft and the another box air shaft are coupled together to align the lifter box air shaft with the another air shaft and define a ventilation conduit. A method includes operating a lifter box unit including evacuating gas from the lifter box unit through a vacuum inlet that defines an air intake that is located along substantially all of an upper, interior edge of the lifter box.