Source: G.B.E. |Stephen Hanley | July 17, 2015
Let’s face it; caulking is not very sexy. Done right, you never see it and you can’t really tell if its working. Not unless you have a Heat, Air, and Moisture (HAM) Penetration chamber like the one at Oak Ridge National Laboratory in Tennessee, that is.
“Reducing air leakage in residential and commercial buildings is among the most cost-effective means to lower energy consumption,” said Diana Hun, building technologies researcher at ORNL. “We have the ability to evaluate air barrier assemblies to determine whether sealants can stand up to the elements and improve energy efficiency.”
The HAM chamber — the only apparatus of its kind — simulates indoor temperatures of 60°F to 90°F and outdoor temperatures of 0°F to 110°F. Additionally, the chamber can subject walls to 10 to 90 percent relative humidity and other outdoor conditions such as rain, solar radiation, and pressures from wind and wind gusts that range from -30 to 30 pounds per square foot.
Energy loss from air leakage in buildings is estimated to be about 4 quads (4 quadrillion BTUs) or about 4 percent of the total energy used in the United States annually, according to the Department of Energy’s Energy Data Book.
Hun and her team at ORNL recently evaluated a new product called Liquid Armor invented by Dow that significantly reduces air leakage and helps to make residential and commercial buildings more energy efficient. The product was introduced to the market in the US in 2014. It is a one-step liquid flashing that can be brushed or sprayed on surfaces to seal gaps, cracks, and seams in the building envelope, and is especially effective on rough openings where windows and doors are installed. The fluid nature of the product allows it to “fill” as well as “bridge” gaps, providing additional robustness of seal.
The elastomeric — or rubbery — liquid adheres well to most substrates, even as buildings settle or adjust to wind pressures and changes in temperature. Additionally, its water-based acrylic formula significantly decreases workers’ exposure to volatile organic compounds (VOCs) and reduces VOC emissions into the atmosphere.
“One of the main advantages a liquid sealant such as Liquid Armor has over tape is that it can be faster to install,” Hun said. “Because it can be sprayed on. Installation can be as much as three to four times faster than tape. Also, the spraying process can be more forgiving and foolproof, and a high-quality seal can be more reliably achieved, especially in areas with complex shapes.”
Hun and her research team evaluated the sealant’s effectiveness by using ORNL’s unique Heat, Air, and Moisture (HAM) Penetration chamber that measures the impact that various environmental conditions have on wall assemblies treated with LIQUIDARMOR.
The US Department of Energy’s Building Technologies Office sponsored the ORNL-Dow collaboration through the US–China Clean Energy Research Center for Building Energy Efficiency, which supports the development of advanced technologies to reduce energy consumption and CO2 emissions in the United States and China. Widespread opportunities for use of Liquid Armor exist in China because construction practices there include minimal building envelope air sealing.