@article {12093, title = {Natural Convection Effects in Three-Dimensional Window Frames with Internal Cavities}, journal = {ASHRAE Transactions}, volume = {107, Part 2}, year = {2000}, month = {06/2001}, address = {Cincinnati, Ohio}, abstract = {

This paper studies three-dimensional natural convection effects in window frames with internal cavities. Infrared (IR) thermography experiments, computational fluid dynamics (CFD) simulations, and calculations with traditional software for simulating two-dimensional heat conduction were conducted. The IR thermography experiments mapped surface temperatures during steady-state thermal tests between ambi-ent thermal chambers set at 0 deg. C and 20 deg. C. Using anon-contact infrared scanning radiometer and an external referencing technique, we were able to obtain surface temperature maps with a resolution of 0.1 deg. C and 3 mm and an estimated uncertainty of 0.5 deg. C and +/-3 mm. The conjugate CFD simulations modeled the enclosed air cavities, frame section walls, and foam board surround panel. With the two-dimensional heat conduction simulation software, weusedcorrelations to model heat transfer in the air cavities. For both the CFD simulations and the conduction simulation software, boundary conditions at the external air/solid interface were modeled using constant surface heat-transfer coefficients with fixed ambient air temperatures.

Different cases were studied, including simple, four-sided frame sections (with one open internal cavity), simple vertical sections with a single internal cavity, and horizontal sections with a single internal cavity. The sections tested in the Infrared Thermography Laboratory (IR lab) were made of PVC. Both PVC and thermally broken aluminum sections were modeled. Based on the current investigations, it appears that the thermal transmittance or U-factor of a four-sided section can be found by calculating the average of the thermal transmittance of the respective single horizontal and vertical sections. In addition, we conclude that two-dimensional heat transfer simulation software agrees well with CFD simulations if the natural convection correlations used for the internal cavities are correct.

}, author = {Arlid Gustavsen and Brent T. Griffith and Dariush K. Arasteh} } @conference {12092, title = {The National Energy Requirements of Residential Windows in the U.S.: Today and Tomorrow}, booktitle = {ACEEE 1996 Summer Study on Energy Efficiency in Buildings: Profiting from Energy Efficiency}, year = {1996}, month = {08/1996}, address = {Pacific Grove, CA}, abstract = {

This paper describes an end-use analysis of the national energy requirements of U.S. residential window technologies. We estimate that the current U.S. stock of 19 billion square feet of residential windows is responsible for 1.7 quadrillion BTUs (or quads) per year of energy use - 1.3 quads of heating and 0.4 quads of cooling energy - which represents about 2\% of total U.S. energy consumption. We show that national energy use due to windows could be reduced by 25\% by the year 2010 through accelerated adoption of currently available, advanced window technologies such as low-e and solar control low-e coatings, vinyl and wood frames, and superwindows. We evaluate the economics of the technologies regionally, considering both climatic and energy price variations, and find that the technologies would be cost effective for most consumers.

}, url = {http://aceee.org/files/proceedings/1996/data/papers/SS96_Panel10_Paper07.pdf$\#$page=1}, author = {Karl J. Frost and Joseph H. Eto and Dariush K. Arasteh and Mehry Yazdanian} } @conference {12115, title = {NFRC Efforts to Develop a Residential Fenestration Annual Energy Rating Methodology}, booktitle = {Window Innovations Conference 1995}, year = {1995}, month = {06/1995}, address = {Toronto, Canada}, abstract = {

This paper documents efforts currently being undertaken by the National Fenestration Rating Councils Annual Energy Rating Subcommittee to develop procedures to quantify the energy impacts of fenestration products in typical residential buildings throughout the United States. Parallel paths focus on (1) the development of simplified heating and cooling indices and (2) the development of a more detailed methodology to calculate the cost and energy impacts of specific products in a variety of housing types. These procedures are currently under discussion by NFRCs Technical Committee; future efforts will also address commercial buildings.

}, author = {Brian Crooks and James Larsen and Robert Sullivan and Dariush K. Arasteh and Stephen E. Selkowitz} }