Hvac Condensate Drain Trap Design

Codes installation leaks clogs connections troubleshooting repair.

Hvac condensate drain trap design.

Trap failures due to freeze up drying out breakage blockage and or improper installation can compromise the seal against air ingestion through the condensate drain 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. 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 weight of the water in the trap is enough to prevent this while still allowing condensation to flow freely.

The important dimensions for a p trap are. This article discusses the inspection and repair or un clogging of condensate disposal systems including air conditioning heat pump or condensing boiler furnace condensate drains condensate pumps and their proper installation as part of our review of condensate piping traps drains. Since p traps seal against air leakage they were the natural solution to prevent air leaking in the condensate drains of early 1900s air conditioning units. Another key component of a p trap is an air vent the air vent prevents the drain that comes after the p trap from siphoning the water in the trap out.

The pull of the water to the drain has to exceed the sucking of the supply fan negative pressure rule of thumb add 2 5 to the static pressure before the fan return and internal to the unit and that s the long end. Do you know the proper way to size a p trap on an hvac unit. The costgard condensate drain seal is a pneumatic flow control that replaces the condensate p trap on air conditioners. The videos below explain why condensate traps are unacceptable and why their replacement with the costgard condensate drain seal is a cost saving alternative.

Traps with insufficient height between the inlet and outlet design deficiency on draw through systems can cause the drain to back up when the fan is on possibly causing. Here is our finished product. The condensate s net column height in the trap h in the accompanying figures is less than the equipment s negative air pressure in inches of water column the condensate will be unable to drain t he condensate trap perhaps is the most overlooked item in the design and installa tion of fan coils and air handlers with cool ing.