Hvac Condensate Drain Line Trap

The drip pan connects to the condensate drain line which carries water out of the home.

Hvac condensate drain line trap.

Air conditioning units pull a lot of water out of the air. A central air system routes condensation through a u shaped trap located in the drain line just outside the air handler. Trap required in condensate line if the condensate drain line is under negative pressure e g upstream of blower as shown here a trap is required. A p trap serves a very important purpose on an a c unit.

Another sign your condensate lines may be clogged is if no moisture is exiting outdoors. See when moist air hits something cold the water condenses out of the air and collects on the cold surface. 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. While most manufacturers don t specify this on this gravity ductless drains it is something to look out for.

The hvac air trap allows liquid condensate to drain from the hvac equipment and simultaneously prevents air from entering or escaping from the equipment. B that the drain lines slope toward the final drainage point at a rate of 1 8 inch per foot. 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 drain pan overflow or water droplet carryover into the duct system. The only code requirements for drain lines removing condensate from hvac equipment are.

The air trap concept has been incorporated into iapmo igc 196 2018 standard for condensate traps and overflow switches for air conditioning systems. A for the installation of a trap in accordance with the unit manufacturer s installation and operating instructions. That is why in the summer your car drips water. The imc states that condensate drains should be trapped according to manufactures specs however wording was added in imc 307 2 4 1 that states that ductless systems must either have a check valve or a trap in the condensate line.

For the primary condensate drain the installer piped 3 4 pvc into a condensate pump which will discharge into a nearby vanity sink prior to the trap via 3 8 vinyl plastic tubing. For the secondary drain system he installed a wet switch within the pan below the unit which will turn the unit off upon water detection.