Deliberations in the technical and ratings committees dominated the second day of the National Fenestration Rating Council (NFRC) Spring Meeting in Alexandria, Va. One new proposal was approved — an optional ventilation rating procedure for operable fenestration products.
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The NFRC 401 ventilation rating procedure seeks to standardize the methods used to measure the ventilation area of doors and windows. The rating will be based on the ratio of frame area to ventilation area. According to ventilation subcommittee chair Ray Garries of MI Windows and Doors, the new rating will go into use as soon as NFRC’s staff can complete the internal procedures for calculations and listing in the organization’s Certified Product Directory. NFRC will also conduct a cost analysis before implementing the proposal.

Because many newer “green” buildings use  natural ventilation to lower costs and improve indoor air quality, the new rating could help building owners make informed decisions when selecting thise products.  Garries says inquiries have already come in about the rating from California, which could be used for the state’s indoor air quality requirements for ventilation.

In other actions, NFRC’s Optical Properties Subcommittee discussed solar optical properties data for glazing materials and systems, and the Research Subcommittee discussed ways to determine standards for vacuum insulated glass.

Another session debated a rating system for daylighting potential that would use existing NFRC visible transmittance (VT) ratings plus known, bright day incident illuminance values. Discussion among the members indicated that a standard for daylighting potential would be more relevant to the commercial market than the residential market.

The NFRC’s Fall Membership meeting will be held October 3-6 in Denver.