The Air-Trap allows liquid condensate to drain from the HVAC equipment and simultaneously prevents air from entering or escaping from the equipment.

Why a Waterless Trap?

The DMS-Series Air-Trap allows water to drain from HVAC equipment and simultaneously prevents air from escaping from or entering the equipment by way of the condensate drain line.

The DMS-Series Air-Trap does not require standing water to prevent gas (typically air) from flowing through the condensate drain line. With the occurrence of condensate, or other water sources within the unit, the water flows out of the HVAC unit, but no gas enters or leaves. When there is no production of condensate or water, there is no water in the trap and there is no gas flow through the trap. Install the DMS-Series Air-Trap in a vertical orientation.

DMS-Series

Maximum Pressures, Connection Sizes & Length

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No More Troublesome "P" Traps

Negative/Positive Pressure

Vertical Orientation

DMS-Series Operation

DMS Air-Traps will properly drain condensate for negative pressures to -1" WC and positive pressures to +5/8" WC while allowing essentially no air to enter or leave through the drain line. After condensate production ceases there will be no standing water within the drain line or trap if line is installed per code, i.e. 1/8" per foot slope or greater toward final drain point and no sags in the line.

Preferred DMS-Series Installation

Preferred DMS Air-Trap installation for a ductless mini split for ease of cleaning trap and drain line.

For ease of maintenance and drain line cleaning the condensate trap location is best placed at the very end of the drain line as shown in Figure 4. Simply attach the DMS Air-Trap to the end of the drain line using plumber’s tape so that it can be easily removed from the line. Once removed, simply wash the trap with water to remove any debris.

Features and Benefits

• Operates dry except when condensate is being produced

• Will not freeze and will never pass gas

• No sludge build-up in bottom of trap

• Easily comes apart for cleaning

• Operates under both positive and negative pressure

• Meets general building codes. For use on HVAC equipment only.

• Meets code IMC Section M307.2.4.1 for Ductless Mini-splits

Specifications

Maximum negative pressure of WC = -1"

Maximum positive pressure of WC = +5/8"

Available connection sizes:

  • 3/4" (25 mm)

  • 5/8" ID Drain Hose

Length 2.95 inches

Flammability rating is UL94 V-0

Air-Traps Meet IMC® Code Section M307.2.4.1

Available Models and Connection Sizes

• 3/4" (25 mm)

• 5/8" ID Drain Hose

Patented: US11808482B1

Condensate Drain Line and Condensate Trap Code Requirements as Outlined in the 2024 UMC (Uniform Mechanical Code) and 2021 IMC (International Mechanical Code) for Mini-split AC Equipment