TIPC Answers Lingering Questions

NFRC’s Policy Committee just finished meeting. The Technical Interpretations Policy Committee (TIPC) provided answers to two key questions that they had been considering.

TIPC is an NFRC Board appointed committee. The committee’s role is to provide a technical interpretation when items found in NFRC’s technical documents cause questions and the answer is not clear.

The first question TIPC addressed was whether or not only one material type of sealant on both the sides and the bottom of a spacer would be considered by the simulation and the test lab to be a single sealed or a dual sealed spacer system.

TIPC reported that in the simulation manual, section 2.7, states that there is a primary seal (edge of spacer to glass) that helps to hold the unit together and to prevent moisture intrusion. The same section also reports that a secondary seal (below spacer) is used to provide structural strength.

TIPC pointed out that section 2.7 does not state that the sealant needs to be two different materials in order to be considered a dual-sealed spacer. Thus, if a spacer is sealed both on the sides and below, it should be reported as a dual-sealed spacer.

A second question TIPC discussed was whether or not revising a report to add a new glass option to an existing matrix with a better center of glass U-factor is required to report using an additional Solar Heat Gain Coefficient (SHGC)/Visible Transmittance (VT) 0.0 and 1.0 table for the new options.

TIPC reported that this is not the case. Instead the initial SHGC/VT of 0.00 and 1.00 tables shall be used for the entire certification cycle and will be modified upon recertification.