P Trap Hvac Condensate Drain Line Design

Trap for draw thru unit condensate beginning to drain away.

P trap hvac condensate drain line design.

A central air system routes condensation through a u shaped trap located in the drain line just outside the air handler. Do you know the proper way to size a p trap on an hvac unit. 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. Minimum h fan outlet pressure in.

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. That is why in the summer your car drips water. All air conditioners have a special drain for. If fan is located before the coil in the system the fan will push small amount of air and water down condensate drain.

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. Been looking at some posts around here and notice a lot of mention of p traps for a c condensate lines. W c 1 2 in. Co ndes at r i p r ec om ndati.

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. Condensate drain pan h 2 minimum sea level when condensate begins to drain off h fan inlet pressure in. 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. See when moist air hits something cold the water condenses out of the air and collects on the cold surface.

Condensate comes from evaporator coil. Minimum maximum sea level. What is a p trap you say. 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.

If fan is located upstream of coil fan will pull water up drain line counter to water flowing down. W c 1 in. I am not sure about code but the need for a trap will depend on design of a c system. 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.

Air conditioning units pull a lot of water out of the air. A p trap serves a very important purpose on an a c unit. The condensate line comes out of the main trunk and runs to the floor just above the drain near the furnace. 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.