Hvac Condensate Drain Trap Design

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.

Hvac condensate drain trap design.

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. 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. A c condensate drains pumps. 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. As air conditioning caught on in the 50s p traps were the standard that every contractor field designed and installed even if it was unknown to them whether the drain pan was at. 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. 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.

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. Do you know the proper way to size a p trap on an hvac unit. Here is our finished product. 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.

Codes installation leaks clogs connections troubleshooting repair. The videos below explain why condensate traps are unacceptable and why their replacement with the costgard condensate drain seal is a cost saving alternative. 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.