Complete 2 cooling system maintenance in Decatur. Check safety and operations. Find upstairs ac unit operating with in manufacturer spec. Replace batteries for co detector customer provided. Tighten gas connector due to loose fitting. Find downstairs American standard unit operating with weak starter kit. Replace starter kit. Find broken supply duct run in crawlspace. Repair duct run for customer. System operating at this time. Suggest surge protection system and suggest air purifier system to improve air quality and prevent.