The U.S. Embassy in Guatemala requires the purchase and delivery of air filters for Air Handling Units (AHUs), including all applicable service fees. The filters will be used to support the operation ... The U.S. Embassy in Guatemala requires the purchase and delivery of air filters for Air Handling Units (AHUs), including all applicable service fees. The filters will be used to support the operation and maintenance of the Embassy's heating, ventilation, and air conditioning (HVAC) systems and to ensure proper indoor air quality and equipment performance.