When condensate drain systems are defined by designers, a p-trap is commonly specified and the geometry defined. When so specified, the contractor’s installation task is relatively simple. Oftentimes, however, the specification simply states that the drain system “shall be trapped” or it makes no reference to drains systems. In either case, contractors must select and install a trap because most plumbing codes simply require them to do so. Unfortunately, it makes little difference whether the trap is designed or selected randomly. The p-trap exhibits so many failure modes that, regardless of the geometry, it is certain to cause damage to the air conditioning system, the building, the building contents and degrade indoor air quality.
The only remedy the industry offers to these costly problems is improvement in system maintenance. The fact is, satisfactory maintenance of such systems is virtually impossible. Even with the best possible trap geometry, the continual maintenance effort required to: (1) prevent flow blockage, (2) keep water in traps during winter operation, (3) prevent trap freeze-up during wintertime, and (4) ensure the trap is full at startup for summer cooling is at best unrealistic. Add to these the design deficiencies to those of randomly selected p-traps and effective maintenance is simply not feasible.
This situation places contractors in an unenviable position. They are forced to install drain systems which are failure-prone and cannot be successfully maintained. Evidence that contractors recognize this is reflected in typical contracts they offer to building owners, which often include the following warranties: compressors and coils – 10 years; condensate drain - 60 days. See 60 Day Warranty
Fortunately, there is a proven effective and reliable solution to condensate drainage problems: The CostGard™ Condensate Drain Seal. To review the contrast in maintenance requirements for the CostGard™ Condensate Drain Seal system and the condensate trap, view this hyperlink: (Trap vs. CostGard™ Condensate Drain Seal).
Some economic reasons why the air conditioning and plumbing contractors may want to take advantage of the features the CostGard™ Condensate Drain Seal offers and other advanced technologies are included in Reference 1, "More Effective Performance Standards in 10 Steps".