Ac Condensate Drain Line Design

Plumbing code citation for installation of air conditioning condensate drain piping.

Ac condensate drain line design.

On our a c the air rushing in through the condensation drain was preventing the water from exiting through the drain. One is the primary condensate line that is generally connected to a location like a tail piece of a bathroom sink drain piece. No trap clean out no vent. Drain s 2015 imc 307 2 2 requires that an air conditioning condensate drain inside diameter should not be smaller than in ch and should not be smaller than the drain pan outlet diameter.

Condensate leaks can be caused by a number of factors. The secondary line usually a pvc pipe will often end. For starters it can originate from a cracked or corroded condensate drain pan. At split system air conditioners heat pumps.

That white line is the condensate drain headed from the wall mounted unit not shown to outdoors. Since the air conditioner is at a negative pressure relative to the outside air the outside air will rush into the air conditioner through any openings the condensation drain is an opening. Uniform mechanical code section 310 0 310 1 condensate disposal. Condensate pumps can be used to elevate the condensate vertically to a point where it will then discharge into a code approved gravity sloping condensate drain line.

Carson dunlop associates sketches left illustrate both acceptable and not recommended locations for the discharge of an air conditioner or heat pump condensate drain line discharge. With no overflow safety switch no clean out and no vent one is just asking for several thousand dollars of damage due to condensate water backing up and overflowing the cooling coil drain pan flooding out this interior furnace closet. It can air lock because there is no vent after the trap. If the condensate drain line is clogged you will need to use a wet dry vacuum or a special pump to unclog the line.

Three quarters of an inch is sufficient for up to 20 tons according to the imc unless the drain outlet size is larger than in ch use t able 307 2 2 for condensate pipe sizing. The pvc drain line can also form cracks or holes due to stress accidental impact or age. Clogs caused by debris or mold can also cause leaks through an overflowing condensate drain pan. Condensate switches imc 307 2 3 states that all hvac equipment that produces condensate must have either a secondary drain line or a condensate overflow switch a secondary drain pan with a secondary drain line or condensate switch or some combination of these installations should be used to prevent overflow if the primary drain line blocks.

The secondary line is considered a backup line so that if the primary line gets clogged the condensate water will then go through the secondary line. Check for lint or crud blocking the opening to the condensate drain line inside the unit. Just pour a cup of bleach in the drain line s access opening near the indoor air conditioning unit. The photo showing flexible air conditioner condensate piping is explained.