Closed cavity facades
Studies show that overall building energy consumption can be significantly reduced by the use of double-skin and closed cavity facades—by as much as 20% in most climates—relative to the baseline of traditional single skin curtain wall facade.
Derick Koprek at Permasteelisa recently shared with us how a closed cavity facade (a compact double skin facade consisting of single glazing on the outside and a DGU or TGU on the inside), creates a ventilated cavity where blinds can be integrated and a low volume of clean, dry air supplied to the cavity to prevent condensation and dust with the cavity at all times. “This provides the thermal advantage of an exterior operable shading device without the high maintenance costs,” Koprek wrote.
Closed cavity facades offer excellent thermal performance in the transparent areas with U-values in the range of U-0.145 to U-0.15. Other benefits include a high degree of solar protection by the automated blind system, reduced maintenance costs, and top-notch acoustic performance, among other perks.
Radiant systems for commercial projects
As architects and designers seek energy-efficient, design-friendly radiant systems, they increasingly recognize the benefits that radiant heating and cooling systems offer.
As far as green building innovations go, radiant solutions have long been popular in Europe, even as they continue to gain steam in the US. Barcol-Air itself has been a large part of the excitement. But some have asked: Can radiant systems be used in a commercial building as the sole sensible heating and cooling system?
The short answer is yes, says Michael O’Rourke at Barcol-Air. He writes in a previous article for gb&d: “Although new buildings with tight envelopes are the best applications, many retrofits have been done over the past 10 to 15 years as older buildings have been updated to allow the use of radiant.”
Examples include the award-winning Edith Green-Wendell Wyatt Federal Building project in Portland, Oregon. The 1970s high-rise steel building wasn’t very energy-efficient, and that was one of the main reasons for its renovation. The building was updated with solar shading on two sides (SE and SW), and the hanging trellis gardens were added on the northwest side. This allowed for plentiful daylight in the space but reduced the overall solar loading to a level where radiant ceiling system was feasible, O’Rourke said. This building renovation, completed in 2013, was awarded a LEED Gold designation.
Barcol-Air manufactures premium radiant heating and cooling systems that deliver optimal comfort using advanced thermal exchange methods. “Radiant can be used for sensible loads—both heating and cooling—and to offset any radiant asymmetry due to cold or hot walls or glass facades in the space,” O’Rourke said in a past interview with gb&d. “But it’s not appropriate for fresh air or dehumidification requirements.”
Therefore, the company offers advanced Active Chilled Beam technology to provide each space with an additional level of ventilation and dehumidification, creating fully integrated heating and cooling operations that positively contribute to LEED accreditation.
Barcol-Air’s Active Beam application offers significant space savings, too, thanks to smaller ductwork requirements. It can be installed tight up against the slab, resulting in reduced floor-to-floor heights and reduced construction costs on new buildings. In addition to low maintenance requirements, Active Beam systems also use the same water temperatures used in radiant panels and exude low noise levels.
Windows currently account for anywhere from 30 to 50% of the heating and cooling energy loss in a building, according to Cascadia Windows & DoorsTechnical Director Michael Bousfield, who recently shared how fiberglass windows impact building performance in an article for gb&d. That means for every dollar spent on heating and cooling, up to 50 cents is lost through the window.
Bousfield says fiberglass is an ideal structural material for window and door frames—specifically fiberglass with a high glass-fiber-to-resin formula. “Nearly 10 times stronger than traditional vinyl, thermoset fiberglass is dimensionally stable, meaning it won’t creep and deflect over time,” he told gb&d. “This stability and strength allow fiberglass frame windows to withstand higher wind load, resulting in larger possible windows—even on tall buildings with high wind loads.”
He says fiberglass also represents less embodied carbon compared to traditional aluminum windows in both sourcing its raw materials and fabrication, carbon draw during its service life, as well as its end of life recycling.
Fiberglass windows are also reported to be impervious to decay, insect attack, and corrosion and can stand up to extreme weather temperatures (-40°F through 350°F and higher) without becoming brittle or soft, giving them a lifespan of 50 to 80 years. “That’s more than four times the lifespan of vinyl/PVC and twice the serviceable lifespan of aluminum windows,” Bousfield wrote.
Metal wall panels
One quick way to determine a product’s true value is to check out whether it has a Declare Label. You can find a list of products with Declare Labels on the International Living Future Institute (ILFI)’s website. Developed by the ILFI, a Declare Label looks at the product source location, the materials that make up the product, and how the product is treated at the end of its life.
Intercept, a modular metal wall panel system from CENTRIA, is one of many top products with a Declare Label. Intercept provides design versatility by incorporating different substrates, depths, slopes, curves, and perforations into an easy-to-install rainscreen. The flat, rectangular metal wall panel system can be applied over any sort of back-up wall system.
Intercept is 98.6% recyclable, has a 20-year finish warranty, can withstand the life span of the building when following proper maintenance procedures, and is Living Building Challenge compliant.