Background
Engineers and designers, more than any other members of the industry, determine the energy efficiency, life-cycle cost, and indoor air quality of buildings. Within the cost limits set by the building owner, engineers and designers are responsible for defining buildings that achieve the best possible performance in terms defined as “Sustainable” and “Green.” Hence, trade-off evaluations between performance and costs are essential parts of successful building design.
Many of the steps necessary for achieving high building performance require “high tech” and expensive components. Others simply require the elimination of detrimental and outdated design practices. The practice of including the failure prone p-trap in the design of air conditioner drain systems is an example of outdated design practices.
The propensity for p-trap failures and some of the consequences are documented in ASHRAE [American Society of Heating, Refrigerating and Air Conditioning Engineers] Standard 62-89R, paragraph 5.6.4, which reads as follows:
Consequences of Trap Failures
Despite this assessment, the condensate trap remains the choice of many engineers and designers as a means of condensate drainage control. This choice, unfortunately, deprives your clients of high performance buildings and any hope of reaching the level of truly “sustainable green buildings”. Some of the many trap failure modes identified by ASHRAE are illustrated in Figure 1. These failure modes, which occur frequently, allow condensate blowing and flooding as illustrated—causing property damage and air contamination. Since all the air in a building passes through the air conditioning unit at a rate of several times per hour, the circulated health threatening pathogens inevitably expose occupants to degraded indoor air quality, as indicated in Figure 2.
Successful Drain System Design and Specifications
Engineers and designers must reject the common practice of specifying p-traps for condensate drain systems and seek an effective and reliable alternative. The CostGard™ Condensate Drain Seal is such an alternative. Tens of thousands are performing successfully in locations throughout the United States, in all kinds of environments: hot and humid to cold and dry. Not one has failed to operate successfully.
A short video, accessible from the home page of this website, shows typical damages caused by failed condensate traps. It also illustrates how the CostGard™ Condensate Drain Seal operates, and how it prevents these damages. Other topics in this website that provide additional information about the functioning of this drain seal are listed below under the headings: OTHER TOPICS
Specifying condensate drain systems with the CostGard™ Condensate Drain Seal can be as simple or as formal as the designer desires.
Simple Specifications
For the most commonly used Unitary Rooftop Units (RTUs)—up to 30 tons—detailed system designs and installation instructions are readily available. Refer to Products-Model-1525 System Kit for a list of the available designs. For these units, the designer may simply define the RTU model and state:
The only constraint on this statement is that the curb height must be adequate to accommodate the drain seal, which is 5.6 inches deep.
In instances where detailed system designs and installation instructions are not available, the same simple statement can be used. Trent Technologies will work with the contractor and designer to define the design and installation instructions necessary to provide a successful condensate drain system. Please contact us with any questions regarding the CostGard™ Condensate Drain Seal and preparation of specifications at (903)-509-4843.
More Formal Specification
For guidance in preparing a more formal specification, go to: Guidelines for Preparing Specifications 