For those of you following the news at ASHRAE earlier this year, you were no doubt surprised by the vote to approve a reduction in permissible fenestration area -- from 40 percent to 30 percent for prescriptive compliance -- in standard 90.1. (Read a Glass Magazine article on the subject). This turn of events is a result of a continuing effort to improve the thermal efficiency of the building envelope.
On the bright side, there was and continues to be a coordinated effort by the entire fenestration industry to maintain the 40 percent level. This is atypical -- normally, the industry is splintered by vested interests at code and regulatory bodies -- and demonstrates how important this issue is to all of us.
Recent discussions of R-value versus U-factor are symptomatic of this industry’s inability to effectively communicate product performance.
It brings to mind how important it is for the fenestration industry to be sure that all of the benefits of windows, doors, skylights and curtain-wall systems are recognized by the building code and architectural community. These benefits specifically include ventilation and daylighting. To fully realize the potential benefits of fenestration systems, the industry needs to:
- Provide a tool that measures the potential opportunity for natural ventilation as part of sustainable designs;
- Establish a metric for the productivity and health-related gains from daylighting;
- Reach a consensus on the energy-related benefits of daylighting; and
- Work towards a consensus on the potential for positive solar heat gain benefits in cold climates.
Achieving the above would allow us to move toward an annual energy performance rating.
Please remember that NFRC is not a fenestration industry organization, nor do we represent their interests. We provide an organizational forum for valid, consensus-driven, energy-related ratings for fenestration products. However, we are tied to the success of the fenestration industry and hope that we can have a role to play in its continued growth.
--Jim Benney is the National Fenestration Rating Council’s chief executive officer. He has been involved in developing product and performance standards for the window and glass industry for more than 25 years. He can be reached at firstname.lastname@example.org.
The opinions expressed here are those of the individual author and do not necessarily reflect those of the National Glass Association, Glass Magazine editors, or other glassblog contributors.