Missing backflow preventer

Air Conditioning and Heat Pumps · Evaporator Coil (Indoor Coil) · printed page 217 (PDF page 218)

Book index entries

Missing Backflow Preventer Backflow Preventer – Missing on Water Cooled Air Conditioners Water Cooled Air Conditioner – Missing Backflow Preventer

Text in the illustration

in some areas, an anti-siphon device such as a backflow preventer is required to prevent possible contamination of the drinking water in the event of a drop in the house water pressure
shutoff valve for A/C water supply
supply plenum
cold air return
evaporator coil
refrigerant lines
furnace
water-cooled air conditioner
outlet pipe
drain
condensate line

Generated explanation

The illustration shows a water-cooled air conditioner connected by refrigerant lines to an evaporator coil in the supply plenum above a furnace. A large cold-air return duct runs beside the furnace, and a condensate line leads from the coil area to a floor drain. The air conditioner has a water supply with a shutoff valve and an outlet pipe discharging to the drain. A dashed circle highlights the missing backflow preventer on the water supply. The annotation explains that an anti-siphon device is required in some areas to prevent drinking-water contamination if house water pressure drops.

Components

water-cooled air conditioner water supply pipe water supply shutoff valve outlet pipe refrigerant lines evaporator coil supply plenum cold-air return duct furnace condensate line floor drain

Defects shown

Missing backflow preventer on the water-cooled air conditioner water supply Potential drinking-water contamination through back-siphonage when house water pressure drops