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Building Science Corp. Study Examines Insulation Performance

first_imgOld newsThe findings aren’t new; they were reported by GBA in a September 2012 article called “Air Leakage Degrades the Thermal Performance of Walls.” In that article, senior editor Martin Holladay wrote, “If the walls were sealed and there was no air flow through the walls, all of the R-13 walls behaved the same. As Gertrude Stein might have put it, an R-13 wall is an R-13 wall is an R-13 wall. ‘When the nominal R-13 walls are sealed and tested, they have the same heat flow, plus or minus 4%,’ said [Chris] Schumacher. ‘They all perform roughly the same.’” RELATED ARTICLES Builders who run the other way when someone suggests using fiberglass batt insulation may want to rethink their point of view. A study released by an industry trade group says that one type of wall insulation performs as well as any other as long as it is installed correctly and the wall has been air-sealed.That conclusion comes from an updated Thermal Metric Summary Report compiled by the Building Science Corporation and released this week by the North American Insulation Manufacturers Association (NAIMA), a trade group representing manufacturers of fiberglass, rock wool, and slag wool insulation.“R-value is R-value,” NAIMA said in reporting the latest results of the multi-year study. “When walls are constructed to the same R-value and properly sealed, all insulation types perform essentially the same.” Air Leakage Degrades the Thermal Performance of WallsA Bold Attempt to Slay R-ValueUnderstanding R-ValueInstalling Fiberglass Right Search continues for an R-value replacementThe industry-funded research is part of what’s turning out to be a very long process aimed at replacing R-value with another metric for describing thermal performance.Joseph Lstiburek, a principal at Building Science Corporation (BSC), announced in 2007 that it was time for the R-value to be retired and replaced with a metric that took into account more complexities of building assemblies and site conditions. As GBA’s Martin Holladay reported nearly four years ago, BSC built a new test rig called a double-guarded hot box with the aim of measuring heat and mass flows. But testing dragged on for years without any firm conclusions.As the report notes, BSC joined with six companies in the industry — including NAIMA and Icynene, a manufacture of open-cell foam — to develop a replacement for R-value.“The Thermal Metric Project was initiated in response to renewed focus on building system performance and increasing use of a broader range of building materials and systems,” the report notes. “These factors highlight the shortcomings of the dominate thermal performance metric, namely R-value. Contemporary insulation materials and systems are more or less sensitive to thermal bridging, workmanship (i.e. quality of installation), internal convention and through convection (i.e. infiltration, exfiltration, wind washing and re-entrant looping).“The impact of such ‘anomalies’ and ‘defects’ is not captured in the standard (label and installed) R-value metric,” it said.Researchers still have more work to do: “At this stage of the research project, the industry partners have not proposed a new metric for quantifying the thermal performance of insulation beyond conventional R-value,” NAIMA said, “and the report does not include any recommendations for a new metric.”But the study did yield a number of observations:Unless a continuous layer of insulation is installed on one side of the wall, all wood-framed walls are subject to thermal bridging, regardless of what type of insulation is used in the stud cavities. Thermal bridging through the framing lowered thermal performance by about 15%.Commercially available heat transfer models do a good job of predicting thermal bridging, as did the ASHRAE Handbook of Fundamentals.All types of insulation show changes in thermal performance with changes in temperature.No matter what type of insulation is used, all wall assemblies show some loss of thermal performance when air is permitted to move through them. A preliminary version of the report was released almost two years ago, NAIMA said, comparing fiberglass batts, cellulose, closed-cell spray foam, and foam sheathing. But open-cell spray foam wasn’t included because of defects in a test wall. The updated version of the report, dated June 2015, also includes test results involving R-15 fiberglass batts and R-15 blown-in fiberglass insulation.NAIMA said that R-15 fiberglass batts performed better than a wall insulated to R-13 with open-cell spray foam and better than R-12 worth of closed-cell foam.“The results of this research clearly demonstrate that there is no single ‘best’ insulation material and that all insulation materials perform equally well when properly air sealed and installed, debunking the claims that spray foam insulation performs better than other insulation types and provides air sealing for the whole building.”last_img read more

Ancajas leaves for Texas fight vs Gonzales

first_imgFILE — Jerwin Ancajas. Photo by Mark GiongcoJerwin Ancajas will still train Thursday before taking the night flight bound for Los Angeles.“Time is of the essence,” Joven Jimenez, Ancajas’ trainer told the Inquirer Wednesday. “Jerwin is ready to rumble.”ADVERTISEMENT Bayron, three foreigners share Pradera lead “Hopefully, he’ll hit 118 before our departure,” added Jimenez. “We’ll only do light training in the United States, just to let the sweat out.”Though Ancajas (28-1-1 with 19 knockouts) is tagged the favorite against Gonzalez (21-1, 8 KOs), Jimenez said they’re not lowering their guards and have covered all bases to ensure victory.Finally able to secure tapes of Gonzalez’s fights, Jimenez said they know what to do on fight night.Ancajas hopes to impress in his American debut, also his first fight under Bob Arum’s Top Rank.ADVERTISEMENT Read Next Typhoon Kammuri accelerates, gains strength en route to PH John Lloyd Cruz a dashing guest at Vhong Navarro’s wedding LATEST STORIES NEXT BLOCK ASIA 2.0 introduces GURUS AWARDS to recognize and reward industry influencers Ancajas will dangle his International Boxing Federation junior bantamweight crown for the fourth time against Mexican Israel Gonzales on Feb. 3 at American Bank Center in Corpus Christi, Texas.Jimenez said they will have light training, but no more sparring, in LA before leaving for Texas on Jan. 28.FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSLillard, Anthony lead Blazers over ThunderSPORTSMalditas save PH from shutout“Jerwin has sparred over 90 rounds and that’s enough,” added Jimenez, who supervised Ancajas’ training camp at their Survival Gym in Magallanes, Cavite.Even Ancajas’ weight is well under control, according to Jimenez, who bared that the 26-year-old pride of Panabo City checked in at 121 pounds after Wednesday’s training session. MOST READcenter_img 2 ‘newbie’ drug pushers fall in Lucena sting 2 dead in California school attack; gunman shoots self PLAY LIST 03:122 dead in California school attack; gunman shoots self00:45Onyok Velasco see bright future for PH boxing in Olympics05:25PH boxing team determined to deliver gold medals for PH01:29Police teams find crossbows, bows in HK university01:35Panelo suggests discounted SEA Games tickets for students02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City Kammuri turning to super typhoon less likely but possible — Pagasa Globe Business launches leading cloud-enabled and hardware-agnostic conferencing platform in PH Brace for potentially devastating typhoon approaching PH – NDRRMC Don’t miss out on the latest news and information. Slow and steady hope for near-extinct Bangladesh tortoises View commentslast_img read more